GHSGT SCIENCE
Review Packet
PHYSICAL SCIENCE SECTION
STRUCTURE AND PROPERTIES OF MATTER
When studying for this portion of the test, be sure to review the following:


Be able to describe atoms and their structure in terms of:
a. atomic mass and atomic number
b. elements (atoms with different numbers of protons)
c. isotopes (atoms with the same number of protons, but different numbers of neutrons)
d. proton, neutron, and electron charge and locations
The properties of solutions, in terms of solutes and solvents.
The GHSGT will focus on the following:
1. Understanding that atoms are composed of a nucleus encompassed by a cloud of electrons
2. Recognizing that electrons are arranged in the electron cloud in energy levels.
3. Understanding that the atomic mass of an atom is concentrated in the nucleus of the atom
4. Identifying the symbol, atomic number, and atomic mass of the first 20 elements on the
periodic table.
5. Recognizing the difference between atomic number and atomic mass.
6. Identifying the effect of differing numbers of neutrons in atoms of the same element, primarily
in the context of radioactive isotopes.
7. Differentiating among elements.
8. Understanding solutions, including describing the components of solutions as solvents and
solutes.
Become Familiar with the following terms:
Element
Atom
Nucleus
Electron cloud
Energy level
Electron shells
Proton
Electron
Neutron
Atomic number
Atomic mass
Mass number
Period
Group
Solution
Solute
Solvent
Saturated
Unsaturated
Supersaturated
Electrolyte
THE ATOM
SUBATOMIC PARTICLES
Nucleus: the center of the atom, contains 99.9% of the mass of the atom, holds neutrons and
protons.
- Proton, p+: has a positive charge; all are identical no matter which element; mass is one amu; the
number of protons determines which element you have – also called the atomic number.
- Neutron, n°: is neutral (no charge); all are identical regardless of the element; mass is one amu;
the number of neutrons of an element can be determined by:
Mass Number – Atomic Number = number of neutrons number
Electron Cloud-the area surrounding the nucleus, is mostly empty space, and holds electrons.
-
Electron, e-: has a negative charge, the mass is 1/1840 amu, in a neutral atom, the number of
electrons equals the number of protons.
ATOMIC NUMBER, Z: Equals the number of protons; determines the identity of the element; if you
change the number of protons, you change the element.
MASS NUMBER, A: The number of protons and neutrons combined; this number is different for each
isotope of an element.
ATOMIC MASS:
All masses of the isotopes of the element averaged together. It is rarely a whole
number.
SUMMARY:
Particle
PROTON
NEUTRON
ELECTRON
Location
Charge Mass (amu) the number in a neutral atom
nucleus
positive
1
same as the
atomic number
nucleus
neutral
1
mass number –
atomic number
electron cloud
negative
1/1840
same as protons
in a neutral atom
PERIODIC TABLE ORGANIZATION
The periodic table is organized by increasing atomic number and is read from left to right.
Each vertical column is called a group or family. All elements in the same family have the
same number of valence electrons (the electrons in the outermost energy level.
Each horizontal row is called a period. All elements in the same period are in the same final
energy level.
The Element Families
Family 1 (1A)
Alkali Metal family
+1 ion
1 valence electron
Family 2 (2A)
Alkaline Earth Metals +2 ion
2 valence electrons
Elements in the first two columns are reactive metals and form compounds easily.
Family 13 (3A)
Boron family
+3 ion
3 valence electrons
Family 14 (4A)
Carbon family
+4 or -4 ion
4 valence electrons
Family 15 (5A)
Nitrogen family
-3 ion
5 valence electrons
Family 16 (6A)
Oxygen family
-2 ion
6 valence electrons
Family 17 (7A)
Halogen family
-1 ion
7 valence electrons
The halogen nonmetals are very reactive and form compounds easily.
Family 18 (8A)
Nobel Gas family
no ion
8 valence electrons
The Noble Gases are very UNREACTIVE and stable because their outermost energy level is
full.
ISOTOPES
An isotope is when you have atoms of the same element that differ in atomic mass. These
atoms have the same number of protons but a different number of neutrons. Mass numbers are the
way you distinguish one isotope from another. Any sample of an element in nature will contain a
mixture of isotopes for that element.
Example:
CARBON
carbon-12
carbon-13
6 protons 6 neutrons
6 protons 7 neutrons
carbon-14
6 protons 8 neutrons
Carbon-12 means this carbon has a mass number of 12.
Carbon-14 and Carbon-13 atoms’ are not as stable as carbon-12 and easily break down.
If an isotope has too many or too few neutrons compared to the number of protons, it is
unstable and will undergo radioactive decay. These radioactive isotopes become different elements
in an effort to become more stable.
SOLUTIONS
A solution is different from an element, a compound, or a mixture. A solution is a mixture of
two or more substances where all parts are identical. The parts will not settle out upon standing and
cannot be filtered. Yet, they are not chemically combined like in a chemical compound. They were
just mixed together in any amount. Examples include tea, coffee, and sterling silver
There are two parts to a solution, the solute (substance being dissolved) and the solvent
(substance doing the dissolving). The solute is in the lesser amount and the solvent is in the greater
amount. Water is called the universal solvent because it dissolves a lot of things.
A solution is saturated when it is holding all the solute that is can at that temperature. So a
glass of tea that has sugar sitting at the bottom of the glass is saturated because it cannot hold any
more sugar in solution. The excess sugar is sitting at the bottom of the glass.
ENERGY TRANSFORMATIONS
When studying for this portion of the test, be sure to review the following:




Understand radioactivity and describe the half-lives of elements
Examine the phases of matter and the related atomic and molecular motion
Analyze energy transformations and the flow of energy in systems
Understand molecular motion involved in thermal energy changes due to conduction,
convection, and radiation.
The GHSGT will focus on the following:
9. Describing the process of radioactive decay in which the unstable nucleus of a radioactive
isotope spontaneously decays.
10. Calculating the amount of a radioactive substance that will remain after one half-life.
11. Analyzing graphs, tables, and other displays of data to determine the length of half-life or the
amount of materials remaining after one half-life.
12. Understanding that as temperature increases, the motion of molecules increases.
13. Describing a solid as a composition of particles closely situated in position giving a definite
shape and definite volume and that little motion occurs between particles as compared to other
phases of matter.
14. Describing a liquid as a composition of particles free to move, giving a definite volume but not
a definite shape and that particles have a greater range of motion as compared to solids.
15. Describing gases as a composition of particles that move more that particles of either a solid or
a liquid, giving no definite volume or shape, and colliding more randomly than particles of
solids or liquids.
16. Understanding that a phase change requires a gain or loss in energy.
17. Describing the two forms of energy encountered during a single energy transformation,
including chemical, heat, light, electrical, and mechanical.
18. Identifying the processes of conduction, convection, and radiation that occur during thermal
energy changes.
Become Familiar with the following terms:
Alpha radiation
Beta radiation
Gamma radiation
Half-life
Solid
Liquid
Gas
Phase change
Melting
Freezing
Sublimation
Vaporization
Condensation
Conduction
Convection
Radiation
RADIOACTIVITY AND HALF-LIFE
HALF-LIFE
Each radioactive element breaks down after a certain amount of time to become stable. This time is
measured in “half-life”. A half-life is the time required for one half of the substance’s atoms to break down
and become stable. The half-life for a substance does not change. Some examples are carbon-14 (halflife of 5730 years) and uranium-238 (half-life of 4.5 billion years). When asked to work a half-life problem,
draw the boxes, like the ones below, to help you answer the question.
All atoms are
radioactive
One half-life later, Two half-lives later,
half are radioactive ¼ are radioactive
Three half-lives later,
1/8 are radioactive
RADIATION
The unstable elements tend to break down spontaneously. They do not have
enough “binding energy” in their nuclei to hold the protons and neutrons together. Most
radioactive nuclei have too many neutrons compared to their protons. These elements
are said to be radioactive. Radioactivity is where rays are spontaneously produced by
the nucleus of an unstable atom. It can be particles, energy, or a mixture of both.
Types of Radioactive Decay:
- Alpha Particle, : Has a +2 charge; the particle is composed of two protons and two
neutrons; Is stopped by skin, tissue paper. These particles are not very energetic.
The atomic number drops by two. It is sometimes written as a helium atom: 24 He
Example: When uranium (atomic number 92) undergoes radioactive decay, it gives
off an alpha particle. The atomic number drops by two and it becomes the element,
thorium, with an atomic number of 90.
- Beta Particle, : Has a –1 charge; comes from a neutron being given off – the
neutron gives off a beta particle (negative) and a proton (positive); the beta particle
leaves and the proton stays in the nucleus. Metal foil stops this particle. The atomic
number increases by one.
Example: When bismuth (atomic number 83) undergoes radioactive decay, it gives
off a beta particle. The atomic number increases by one and it becomes the
element polonium, with an atomic number of 84.
-
Gamma Ray, : Has no mass or charge because it is energy. It is high-powered
electromagnetic radiation and it is stopped by lead, concrete.
Uses of Radioactivity
- Medicine: Radiation is used as a form of therapy for cancer. X-rays and gamma
rays produced by cobalt-60 or cesium-137. Radioactive elements can be used as
tracers that can follow certain chemical reactions inside living organisms.
- Industry: Food may be exposed to gamma rays in an effort to kill bacteria and other
parasites in the food in hopes to limit the number of food poisoning cases.
- Radiochemical Dating: Radioactive isotopes are used to measure fossils and other
artifacts. While an organism is alive, it takes in isotopes. Once the organism dies,
the isotopes do not enter the body anymore. Scientists can estimate how much of
the radioactive isotope was present in the body to begin with and then determine
how much is currently left. Carbon-14 is a common isotope measured.
- Too much radiation can be lethal. You are exposed to radiation every day by
watching television, standing in the sun, and even standing in your basement. The
goal is to not get exposed to too much radiation. Too much radiation can result in
cancer or other diseases. This happens when the radioactive substance causes
damage to your DNA and chromosomes. This damage to the DNA is called
mutations. This in turn causes changes in your cells.
- Fuel/Electrical Source: The energy produced in nuclear reactions can be used as a
fuel source. Fusion is the result of nuclei combining and giving off huge amounts of
energy. This occurs in the sun. Fission is the splitting of an atom into two and
releasing energy at the same time.
STATES OF MATTER
Solids have definite shape and definite volume. For the most part, solids can be carried
around without the help of a special container. The molecules or atoms in a solid are
densely packed together and vibrate back and forth in their own space. The atoms
cannot change positions. Examples: rock, paper.
Liquids have no definite shape and a definite volume. They take on the shape of the
container that they are in. The molecules or atoms in a liquid are packed together, but
not as densely as a solid. They can slide around each other but cannot break apart.
Examples: water, mercury
.
Gases have no definite shape and no definite volume. They expand to take on the
shape and volume of the container they are in. A gas’ molecules or atoms have more
energy than a solid or liquid and they can go anywhere within their container.
Examples: helium, air.
PHASE CHANGES
Each of the three main states of matter can change into another state by going
through a phase change. Remember as a solid becomes a liquid becomes a gas,
temperature is increasing and the molecules in the substance are moving faster.
Substances are made to change phases by adding or taking away heat energy. There
are six phase changes.
Melting
solid becomes liquid
Vaporization (boiling)
ENDOTHERMIC
Sublimation
solid becomes gas
absorbs heat
liquid becomes gas
Freezing
Condensation
Deposition
loses heat
loses heat
loses heat
liquid becomes solid
gas becomes liquid
gas becomes a solid
absorbs heat
absorbs heat
EXOTHERMIC
Be sure you understand a heating curve. See below:
G
L
Temp.
S
Energy
Phase changes are physical changes. Physical changes do not produce a new
substance. They produce the same substance with new physical properties. For
instance, water may change from a solid to a liquid. Its volume and density will change,
but it is still water. Examples of physical changes include melting, freezing,
condensation, vaporization, sublimation, cutting, breaking, mixing, and dissolving.
Chemical properties cannot be observed unless the substance you are observing
becomes something new. The particles of one substance undergo a chemical change
and become something new. Chemical properties include such properties as
flammability. You cannot observe this in paper unless the paper burns. Then, it is no
longer paper.
There are several evidences of chemical changes. We also call these chemical
reactions. These are:
- Formation of a new substance (solid precipitate, gas bubbles)
- The production of energy (heat or light)
- The absorption of energy
- Appearance of a new color or odor
Examples of chemical changes include combustion (burning), fermentation, metabolism,
electrolysis, rusting – anything that involves a chemical reaction.
ENERGY TRANSFORMATIONS
Energy is the ability to do work (work involves a change in movement). Energy is the ability to cause
change. The units for energy are joule, J. All matter contains some form of energy because all matter
has the ability to do work or cause change.
There are changes in forms of energy. This is where energy changes from one type to another. Energy
cannot be created or destroyed, just converted from one form to another. When you rub your hands
together, mechanical energy (moving your arms) turns into heat energy in your hands due to friction.
MECHANICAL
HEAT
CHEMICAL
ELECTRICAL
LIGHT
associated with motion. Ex. waterfall, sound, running.
internal motion of particles of matter. The faster the particles move, the more
heat energy is present Ex. rubbing hands together.
stored in bonds that hold atoms and ions together. Ex. fire, energy to move
muscles
moving electrical charges. Ex. lightning, radio
visible portion of the electromagnetic radiation
Examples of Changes from One Form of Energy to Another
Chemical to electrical
Electrical to heat
Electrical to sound
Electrical to chemical
Electrical to mechanical
Chemical to mechanical
Mechanical to electrical
Flashlight battery
toaster
telephone, door bell
human sight
turning on a ceiling fan
energy in food helping your arms move to throw a ball
water turning a turbine which then moves a magnet to generate
electricity
HEAT TRANSFER
Heat is energy, sometimes called thermal energy. The heat of an object is the total kinetic energy of the
random motion of its atoms and particles. When a substance is heated, its molecules move faster and further apart.
Heat is always transferred from the hotter object to the cooler object. Dark colored objects absorb more heat than
light colored objects. That is the reason tennis players wear white!
Conduction:
Heat is transferred from one object to another by direct contact. The two substances must be touching. An
example of conduction is the hot chocolate heating the cup it was poured into. Substances that are conductors
transfer heat very easily - iron, copper, and aluminum. Insulators slow down the conduction of heat - air and glass.
Convection:
Heat is transferred through currents of liquids and gases. As a fluid gets warmer, its
molecules spread out and become less dense. This fluid will rise because it is now less dense
than the fluid on top of it. As it rises, colder fluids fall. This cycle forms a current of warm
rising fluid and cold falling fluids. This is called a convection current. Water circulating in the
oceans or world wind currents are examples of this type of heat transfer.
Radiation:
This type of heat transfer requires no matter. Radiant heat is the transfer of energy by
electromagnetic (infrared) waves. Examples of radiation are when you feel the heat from the fire
or the sun’s heat
FORCES, WAVES, AND ELECTRICITY
When studying for this portion of the test, be sure to review the following:
a. Understand the relationship between force, mass, and motion.
a. Calculate velocity and acceleration
b. Apply Newton’s First Law of Motion, the law of inertia.
c. Relate falling objects to the force of gravity
d. Understand the difference between mass and weight.
e. Calculate work and mechanical advantage
b. Describe the properties of waves
a. Understand that all waves transfer energy
b. Associate frequency and wavelength with the energy transferred by
electromagnetic and mechanical waves.
c. Understand the concepts and can identify examples of reflection, refraction,
interference, and diffraction.
d. Analyze the effects of different mediums on the speed of sound.
c. Understand the properties of electricity and magnetism
a. Describe magnetism and electrical charges in the context of electricity,
magnetism, electromagnets, and simple motors.
Assessment will focus on the following:
1. Using the following formulas to solve for velocity and acceleration:
vf - vi
Velocity: v = d/t
Acceleration: a =
T
2. Apply knowledge of Newton’s First Law of motion to give situations:
a. An object in motion stays in motion unless acted upon by an unbalanced force.
b. An object at rest remains at rest unless acted upon by an unbalanced force.
3. Understanding that gravity causes objects to accelerate as they fall.
4. Understanding factors that affect the force of gravity on an object.
5. Explaining the difference between mass and weight.
6. Calculating work using the formula W = f d (Work = force x distance)
7. Understanding the concept of mechanical advantage in relation to simple machines
8. Understanding that waves carry energy
9. Relating frequency and wavelength to the energy carried in waves
10. Understanding how frequency and wavelength are related.
11. Understanding that electromagnetic waves do not require a medium
12. Understanding how electromagnetic waves differ in the amount of energy transferred
based on position in the electromagnetic spectrum.
13. Relating frequencies and wavelengths on the electromagnetic spectrum to technological
advances such as microwaves and radio waves.
14. Understanding how light interacts with lenses and mirrors
15. Using the terms absorption, reflection, refraction, interference, and diffraction to describe
how waves (including sound waves) interact with obstacles, within mediums, and with
other waves.
16. Describing how the speed of sound varies with the type of medium and temperature of a
medium.
17. Relating magnetism and electricity.
18. Describing electromagnets, including their uses in electric motors, generators, radio,
television, and other technologies.
Become Familiar with the following terms:
Gravity
Force
Inertia
friction
Mass
Weight
Work
Power
Speed
Velocity
Acceleration
Simple machine
Wave
Wavelength
Frequency
Reflection
Refraction
Electric current
Static current
Electric circuit
Conductor
Insulator
Electromagnet
Wet cell
Dry cell
Ohm’s Law
FORCES
A force is a push or pull that starts, stops, or changes the direction of an object. Force transfers energy to an object.
To determine the amount of force being used, you need the mass of the object and its acceleration. Force is
measured in Newtons, N.
The equation is:
Force = mass x acceleration
Forces that are in opposite directions and equal in size are called balanced forces. The larger arrow indicates in
which direction the object will move.
A
+
=
B
+
If the two forces are exerted in the same direction, they
combine and should be added together (A).
=
0
When forces are balanced, there is no change in
motion (B).
C
+
=
If the forces are exerted in exactly opposite directions and are not
equal in size, then you must subtract the smaller force from the larger
to get the net force (C).
Friction is a force that opposes motion. It slows down an object. Motion of an object is going to occur
when the forces acting upon it are unbalanced, like in Figure C. One force cancels out the effects of a smaller force.
There are three types of friction: fluid friction, rolling friction, and sliding friction. Fluid friction has the least
amount of force and sliding has the most.
NEWTON’S FIRST LAW (Law of Inertia)
Newton’s first law states that an object in motion will remain in motion and an object at rest will remain at
rest unless acted upon by an unbalanced force. An object placed on a desk stays there until someone or something
pushes it off. A ball thrown in space will continue forever until it hits something. Objects tend to keep on doing
what they're doing. In fact, it is the natural tendency of objects to resist changes in their state of motion. This
tendency to resist changes in their state of motion is described as inertia. Inertia is the resistance an object has to a
change in its state of motion. The more mass an object has, the more inertia an object has. An object with a lot in
inertia is difficult to get moving and also harder to stop once it is moving.
A ball thrown on earth will not keep going forever. The ball thrown on earth is acted on by gravity and
friction. So it slows down and falls to earth. Gravity and friction are the unbalanced forces.
GRAVITY
The universal Law of Gravitation states that every object in the universe is attracted to every other object in
the universe. This force of attraction depends on the mass of the two objects as well as the distance that separates
them. The more mass it has, the greater its gravitational force. The closer the two objects are, the greater the
gravitational force. On earth, when you let go of an object, it falls to the ground at 9.8m/s 2. This is acceleration due
to gravity. Objects accelerate as they fall due to gravity.
Gravity is measured by weight and the unit is the Newton, N. If you change the force of gravity, you will
change the weight. Keep in mind that the amount of matter – the mass – does not change - only the force that is
pulling on that matter changes and this is reflected in a change in weight. Weightlessness occurs when the force
acting upon an object is equal and opposite to the force of gravity.
WORK
Force is needed to move an object and in doing so, work is done. In order for work to be done, you must be
lifting something. Lifting a book is work. Simply carrying the book across the room or holding the book above
your head is not considered work.
The equation is: Work = Force x distance
The unit for work is joules (Newton-meter).
MACHINES
Simple machines help us make better use of our muscle power to do work. A Machine produces force and
controls the direction of force, it cannot create energy. Simple Machines help us lift, pull, increase elevation of
heavy things, change the direction of the force, increase the force, split things, fasten things, and cut things. We all
use simple machines everyday, opening a door, turning on the water faucet, going up stairs, or opening a can of
paint. Bottom Line: They are simple devices used to make work easier.
Remember work is calculated by force times distance. If you change force or distance, the amount of work
will change. EFFORT FORCE is the amount of force that is applied to the machine by you. The force opposing the
effort force is the RESISTANCE FORCE - often the weight of the object.
Mechanical advantage is the number of times a machine multiplies force. It is the ratio of the force that
comes out of a machine to the force that is put into the same machine. The formula for mechanical advantage is:
Actual mechanical advantage = resistance force  effort force.
The formula for ideal mechanical advantage is calculated by:
Ideal mechanical advantage = effort length  resistance length
There are six simple machines. One group includes the inclined plane (ramp), the screw, and the wedge.
The second group includes the pulley, the wheel and axle, and the lever. A compound machine is a combination of
two or more simple machines. The mechanical advantage of a compound machine is greater than that of just one
simple machine. Example: mechanical pencil sharpener - inclined plane, a wheel and axle.
MOTION
In order for motion to occur, there must be unequal forces. To measure motion, calculate the speed of the
object. The formula for speed is: Speed = distance  time
The speed and direction of an object’s motion is called velocity. Constant speed means that the object is
not changing its motion. Average speed can be calculated by taking the total distance traveled divided by the total
time elapsed.
Velocity is speed in a particular direction. There are times when an object needs to
change its velocity. This is done by slowing down or speeding up. Once motion gets started,
unequal forces allow for speeding up or slowing down. “Speeding up” is called acceleration.
Negative acceleration is called deceleration (“slowing down”).
The formula for acceleration is:
Acceleration = (final velocity – starting velocity)
Projectile Motion is the motion of a thrown ball. The ball initially curves up or stays straight and
then arcs back down to the surface. This arcing motion is due to gravity pulling down and
friction slowing it down.
WAVES
A wave is a disturbance that transfers energy through matter or through space. Some waves, like sound
waves, must travel through matter while others, like light, can travel through space and do not need a material to
move through. Energy is transferred to nearby particles and they move, causing other particles to move. Energy is
transferred from one place to another. The particles of matter do NOT move along with the wave. ONLY the
energy that produces the wave moves with the wave.
Waves can be compressions of energy (compression / longitudinal wave) or made up of
up and down movements (transverse wave). An example of a compression wave is sound.
Examples of transverse waves include water waves and earthquakes.
Parts of a Wave:
A. Amplitude - the height of a wave above or below the
midline
B. Crest - the peak or top of the wave
C. Midline - original position of the medium before the waves
move through it.
D. Trough - the lowest point of the wave
E. Wavelength (cycle) - the distance between two peaks.
Relating Frequency and Wavelength
Frequency is the how fast the wave is moving. If you stand in one spot and watch a wave go by, it is the
number of crests that go by in a second. A long wave (one that doesn’t have too many crests and has a long
wavelength) has a low frequency. A short wave (one that has a lot of crests or a short wavelength) has a high
frequency. The higher the frequency, the more energy a wave has. Waves with short wavelengths have more
energy than larger wavelengths.
The speed or velocity of a wave depends on the wavelength and the frequency. The formula for wave
speed is:
Speed = wavelength x frequency
THE ELECTROMAGNETIC SPECTRUM
The electromagnetic spectrum is an order of electromagnetic waves in order of wavelength and frequency a long wavelength has a low frequency, a short wavelength has a high frequency. Electromagnetic waves can travel
through space. They do not need to travel through a medium like air or water, though they can.
The Spectrum in Order
Least E
Radio Waves
lowest frequency and longest wavelength, used for communication (radio and TV)
Microwaves
used in cooking and for RADAR
Infrared Waves
cannot be seen, felt as heat, “below” red, used for cooking, medicine, night sight
Visible Light
portion of the spectrum that your eye is sensitive to, consists of seven colors
(ROYGBIV), red has the lowest frequency/energy and violet has the highest
frequency/energy
Ultraviolet Waves
present in sunlight, “beyond” violet, energy is enough to kill living cells, used for
sterilization
X-Rays
energy is enough for photons to pass through
the skin, for medicine
highest frequency, shortest wavelength, certain radioactive materials emit them, have
Gamma Rays
tremendous ability to penetrate matter, used in the treatment of cancer
WAVE INTERACTIONS
When a wave hits a piece of matter, the wave can be absorbed or it can be reflected.
Reflection
 the bouncing back after a wave strikes an object that does NOT absorb the wave’s energy.
 The Law of Reflection states that the angle of the incidence is equal to the angle of reflection.


In other words, the angle that it hits the object at will be the same angle, in the opposite
direction, that the waves leaves the surface.
There are three types of mirrors that reflect light. PLANE - flat surface, reflected image is the same size.
CONCAVE - curves inward, like the bowl of a spoon, reflected image is either enlarged (original image was
close to the mirror ) or the reflected image is smaller and upside-down (original image was far away).
CONVEX - curves outward, like the back side of a spoon, reflected image is always smaller and right side up,
provide a wide angle of view so a large area can be seen.
The reflection of sound is called an ECHO.
Refraction
 The bending of waves due to a change in speed. This time the wave is absorbed and not reflected.
 Waves move at different speeds in different types of matter. Temperature can also affect the speed of a wave.
 Examples include prisms (bends white light into its component colors), lenses like glasses and contacts, and a
mirage.
Diffraction
 The bending of waves around a barrier. When a wave encounters a barrier, it can go around it.
 Electromagnetic waves, sound waves, and water waves can all be diffracted. Diffraction is important in the
transfer of radio waves. Longer AM wavelengths are easier to diffract than shorter FM wavelengths. That is
why AM reception is often better than FM reception around tall buildings and hills.
 Examples include rainbow glasses, diffraction gratings.
Interference
 The phenomenon which occurs when two waves meet while traveling along the same medium. The
interference of waves causes the medium to take on a shape which results from the net effect of the two
individual waves.
 When two waves’ crests or troughs combine, there is an additive effect – this is called constructive interference.
When one wave’s crest and another’s trough combine, there is a subtractive effect – this is called destructive
interference.
Constructive interference
Destructive interference
SOUND
Sound moves from its source in the form of compression waves. Sound is a form of energy that causes the
molecules of a medium to vibrate back and forth. Sound cannot travel through space or a vacuum. Materials that
can easily bounce back (elastic) transmit sound easily. Solids are generally more elastic than liquids or gases
because the molecules are not very far away and bounce back quickly. Elasticity increases the speed of sound; If the
objects are in the same phase (ex. both liquids), sound goes slower in the denser medium. As temperature increases,
the speed of sound increases. Sound travels faster at higher temperatures.
DOPPLER EFFECT
This is a common occurrence that depends on the frequency of sound (or light) waves. There is a change in
pitch whenever there is motion between the source of the sound (or light) and its receiver. Either the source of the
sound or the receiver must move relative to the other. Consider an ambulance siren moving towards you. Each time
the siren sends out a new wave, the ambulance moves ahead in the same direction as the wave. This gives shorter
wavelengths and higher frequencies because the waves get pushed together. So, the pitch goes up. As the
ambulance passes you, it is traveling in the opposite direction and the waves spread out. Wavelength gets longer,
frequency gets lower, and the pitch goes down. This also happens with light when light from a star is being sent
back to earth. If the star is moving away relative to the earth, the light gets shifted to the red side of the spectrum,
called a red shift.
ELECTRICITY AND MAGNETISM
METHODS OF GENERATING ELECTRICITY
Electricity is a form of energy called electrical energy. It is basically moving electrons. It can be produced in
several ways.
 Static Electricity - This is a build up of electrical charge when electrons are exchanged from one object to
another. Once they move to another object, they remain on that object. Static electricity is a result of
friction. Friction separates electrons from the surface of an object whose atoms hold electrons loosely.
Some good ways to generate static electricity are to rub opposite substances together like silk and glass or
plastic and wool.
 Electric Current - This is a streams of electrons that flow through a conductor, like a wire. An electric
current can be produced chemically, by moving water (hydroelectric), by solar cells (using sunlight), by
wind, and by nuclear radiation (fission reaction).
a. Chemical energy comes from a wet cell or a dry cell battery. It changes chemical energy into
electrical energy. It is a reaction that is produced as atoms within a substance exchange, transfer, or
lend electrons to another atom within the substance of the cell. An electric cell contains two
electrodes, two different substances. In a wet cell, the electrodes are put in an electrolyte (liquid that
can carry an electric current). The electrodes react with the electrolyte solution and release electrons.
Electrons move from the negative electrode to the positive electrode through a wire. A dry cell works
that same way except there is a solid paste, like ammonium chloride, instead of the liquid electrolyte.
b. Hydroelectric power, nuclear energy and wind energy are generated through electromagnetism.
The moving air or water turns a turbine. The turbine moves a magnet through a coil of wire. This is
called electromagnetic induction. Electromagnetic induction is the process of inducing an electric
current by moving a magnetic field through a wire coil without touching it – this is what a generator
does and this is how water produces electricity.
INSULATORS AND CONDUCTORS
Conductors are materials that are good at carrying an electric charge. Insulators keep an electric charge
from flowing. Good conductors of electricity include metals, water, electrolytes (solutions containing ions), and the
human body. Good insulators include nonmetals, rubber, plastic, and wood. Sometimes an insulator and a
conductor are put together to keep electricity flowing in a particular direction. A copper wire is coated in plastic to
protect anyone from getting electrocuted when they touch the wire.
ELECTRICAL UNITS
There are three ways to measure electricity. They are current, voltage, and resistance.
1. Current: This is the rate at which electric current flows through a wire. It is the number of electrons that
pass by a specific point in a circuit in one second. The symbol is “I” and is measured in amps (A).
2. Voltage: Electrons need energy to force the electrons through the wire. Voltage is the amount of energy
available to move the electrons. The higher the voltage, the more work the electrons can do. The symbol
for voltage is “V” and it is measured in volts (V).
3. Resistance: This is the measure of how difficult it is to move electrons through a circuit. It is the force
opposing the flow of electrons. Good conductors have a low resistance and poor conductors have a high
resistance. Resistance depends on the material’s length, thickness, and temperature. The symbol for
resistance is “R” and it is measured in ohms ().
Ohm’s Law relates current, resistance, and voltage:
Current = voltage  resistance
MAGNETISM
Magnetism is a universal force like gravity. A magnet always has two poles - north and south. Like poles
repel each other and opposite poles attract. There is a magnetic field around a magnet and the invisible lines of
force run from one pole to the other. See below – iron filings show the magnetic lines of force.
A magnetic field can be produced using a current through a wire and a piece of metal that can be
magnetized. Electricity and magnetism are related. Electricity can produce a magnetic field and magnetism can
produce an electric current.
ELECTROMAGNETISM
An electromagnet is a temporary magnet. As long as there is a current flowing, a magnetic field is present.
A simple electromagnet consists of a battery, copper wire, and an iron nail. The strength of the electromagnet
depends on the number of turns in the wire coil and the size of the iron core. The greater the number of turns, the
stronger the magnetic field that is produced.
Magnets are used in electric motors. An electric motor is a device that produces a direct current. It
contains an electromagnet, a permanent magnet, and a commutator. The electromagnet is placed between the poles
of the permanent magnet. The poles repel and attract each other and the electromagnet spins. Electric energy is
converted into mechanical energy. This is the opposite of a generator.
Magnets are also used in television sets. The non-plasma televisions all have a cathode ray that uses
electrons and fluorescent materials to produce images on a screen. An electromagnet changes the path of the beam
of electrons which allows it to sweep the television screen many times a second.
A transformer is a device that uses electromagnetic induction to change the voltage of a current.
Transformers are basically iron cores with wires wrapped around them. There are transformers at the power plant,
at power substations, and on the utility pole near your house. The one near your house looks like a trash can on the
utility pole. A transformer works by stepping up or stepping down the voltage of electricity. More current in a wire
means that more energy is wasted due to resistance in the wire. Power companies want to limit the amount of
energy wasted. When energy is transmitted over a long distance, the voltage is raised and the current is lowered.
The step up transformer raises the voltage. For instance a power plant will step up the voltage from 20,000
volts to 250,000 volts to run the electricity through the long distance transmission lines. The primary coil has a
certain number of turns with the wire. If the secondary coil has twice as many turns as the primary coil, the voltage
will be twice as much in the secondary coil.
LIFE SCIENCES SECTION
CELLS AND HEREDITY
When studying for this portion of the test, be sure to review the following:
1.
Describe the structures of cells and the structure of their components.
a. Examine the similarities and differences between prokaryotic and eukaryotic
2. Explain the process of inheritance of genetic traits.
a. Differentiate between DNA and RNA, recognizing the role of each in heredity.
b. Demonstrate understanding of Mendel’s Laws in genetic inheritance and variability.
c. Discuss the use of DNA technology in the fields of medicine and agriculture.
3. Analyze the similarities and differences between organisms of different kingdoms.
Assessment will focus on the following:
19. Describe the roles of cell organelles in the following:
a. information feedback
d. protein construction
b. motility
e. reproduction
c. obtaining, storing, and using
f. transport of material
energy
g. waste disposal
20. Differentiating the functions of the macromolecules:
a. carbohydrates
c. nucleic acids
b. lipids
d. proteins
21. Understanding differences between DNA and RNA
22. Describing how DNA stores and transmits information
23. Understanding Mendel’s Laws as they apply to variability between generations and cell division.
24. Understanding how DNA technology is used today in medicine and agriculture, including, but not
limited to:
a. Environmental factors in mutation
b. Genotype and phenotype
25. Understanding the relationships between single-celled and multi-celled organisms, on a broad
conceptual level.
26. Differentiating how organisms from different kingdoms obtain, transform, and transport energy
and/or material.
Become Familiar with the following terms:
Cell
Response
Stimulus
Prokaryote
Eukaryote
Cell wall
Cell membrane
Cytoplasm
Vacuole
Mitochondrion
Chloroplast
Nucleus
Chromosome
Endoplasmic
reticulum
Golgi bodies
Ribosome
Homeostasis
Isotonic
Hypotonic
Hypertonic
Osmosis
Diffusion
Carbohydrate
Lipid
Nucleic acid
Protein
Double helix
Replication
Translation
Transcription
Photosynthesis
Respiration
ATP
Mitosis
Meiosis
Interphase
Prophase
Metaphase
Anaphase
Telophase
Genetics
Heredity
Dominant
Recessive
Homologous
Alleles
Gametes
Species
Trait
Genotype
Phenotype
Nondisjunction
Punnett square
Kingdom
Phylum
Class
Order
Family
Species
Genus
Pollen
Pollination
THE SIGNIFICANCE OF BIOLOGY
Biology is the study of life and living organisms. An organism is a complete, individual, living
thing. All organisms are formed from the same basic building block – cells. Most cells are so small that
you cannot see them. Cells are not only the structural units of living things, they are the functional units as
well. They are the smallest units that carry on the activities of life.
DIVISIONS OF BIOLOGY
Originally, there were two fields of biology, only botany and zoology. Now there are many. Here
are a few:
1. Anatomy - The study of the external and internal structures of organisms.
2. Biochemistry - The study of the chemical make-up and processes of organisms.
3. Botany - The study of plants.
4. Cell Biology - The study of the structure and activities of living cells.
5. Ecology - The study of how organisms interact with one another and with their environments.
6. Evolutionary Biology - The study of how organisms have changed throughout time.
7. Genetics - The study of heredity, or how traits are transmitted from one generation to another.
8. Immunology - The study of infection protection
9. Microbiology - The study of organisms too small to be seen without a microscope.
10. Physiology - The study of how organisms carry on their life processes and how various parts of
the organisms perform their special functions.
11. Zoology - The study of animals.
CHARACTERISITICS OF LIVING THINGS
1. Organisms are highly organized. Every living cell is a highly complex structural and chemical
system.
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Organism use energy. All living things need energy because they are constantly building the
substances that they need. The sum of this chemical building up and breaking down is known as
metabolism.
Organisms grow and develop.
Organisms cannot live forever.
Organisms reproduce themselves.
Organisms respond to stimuli. Any condition to which an organism responds to is called a
stimulus. What an organism does as a result of the stimulus is a response. The ability to respond
to stimuli is typical of all living organisms. This property is called irritability.
Organisms adjust to their environment. To survive, an organism must adjust to changes in its
environment. Any change in an organism that makes it better suited to its environment is called
an adaptation.
THE CELL THEORY
1. All organisms are composed of cells. (Schleiden and Schwann)
2. Cells are the basic units of structure and function in organisms. (Schleiden and Schwann)
3. All cells come from preexisting cells. (Virchow)
The virus does not fit this theory. It is a packet of nucleic acid wrapped in a protein coating. It
possesses only a few structures of a cell. It relies on a host cell to help it reproduce. It cannot reproduce on
its own.
DIFFERENCES IN CELLS
Cells can be grouped according to their similarities and differences. All cells can be divided into
two categories – prokaryotes and eukaryotes.
A PROKARYOTE is a cell that lacks a true nucleus and does not have membrane-bound
organelles. The DNA in a prokaryote is a single circular molecule. They have no mitochondria,
chloroplasts, Golgi bodies, lysosomes, vacuoles, or endoplasmic reticulum. They do have a cell wall and
a cell membrane. Bacteria and blue-green algae are prokaryotes.
A EUKARYOTE is a cell that possesses a well-defined nucleus surrounded by a nuclear
membrane. The DNA is in the form of complex chromosomes. The organelles are membrane bound.
There is a greater division of all the jobs to be done in an eukaryotic cell. These cells are found in plants,
animals, fungi, and protists.
Eukaryotic cells also differ between plants and animals. Plant cells contain three
structures not found in animal cells – cell walls, large central vacuoles, and plastids.
Centrioles are found in some, but not all types of plant cells. They are found in all animal
cells.
Animal Cell
Plant Cell
STRUCTURE AND FUNCTION OF CELLS
Cells differ in size, shape, and function. But most share several common traits. There are two
main types: animal and plant. Both of these cell types have the following ORGANELLES (cell
structures):
controls the activities of the cell and holds the DNA. The “brain” of the cell.
gel-like substance inside all cells in which most of the cell’s life processes take place.
contain complex genetic information that directs all the cell’s activities. Located in the
nucleus.
Cell membrane: outer covering of the cell. It regulates what enters or leaves the cell and it allows for all
the communication between cells.
Mitochondria: supplies the energy that the cell needs to do work. They release this energy from the
nutrients taken up in the cell.
Endoplasmic Reticulum (ER):
transports proteins from one part of the cell to another. It is the internal
support system for the cell. There are two types – rough ER (contains ribosomes) and
smooth ER (no ribosomes)
Ribosome:
Attached to ER, they make the proteins. Ribosomes are located either on the
endoplasmic reticulum or free within the cytoplasm of the cell.
Lysosomes:
storage containers that hold enzymes that break down larger food molecules into smaller
ones.
Golgi Bodies
areas for the storage and packaging of chemicals. They are formed from pinched off ER.
They look like flattened balloons.
Microtubules
long, slender tubes that hold the cells more rigid. They support the cell and maintain its
shape.
Spindle Fibers microtubules that appear during cell division. These are temporary structures that help
guide the chromosomes through the cytoplasm.
Centrioles
small dark bodies located outside the nucleus in many cells. They exist in pairs and
perform a function only during cell division. They appear only in animal cells.
Cilia
short, threadlike projections that stick out on the surface of the cell. They aid in
locomotion as well as moving substances along the surface of the cell.
Flagella
Long hairlike projection that sticks out on the surface of the cell. There are usually just
one or two per cell. They aid in the locomotion of unicellular organisms.
Nucleus:
Cytoplasm:
Chromosomes:
Plant cells also have:
Cell wall:
rigid wall that supports and protects the cell and is located outside the cell membrane.
Chloroplasts:
Vacuole:
Plastids:
stores chlorophyll. It allows plants to make their own food by converting light energy
into chemical energy.
storage containers for food, water, and other materials. Not all animal cells have
vacuoles. The interior of plant cells has one large one.
storage containers that hold food or pigments.
CHANGING TO STAY THE SAME
An important property of living things is the ability to maintain a nearly constant internal
environment. This is important because cells are extremely delicate. Cells cannot tolerate a change in
temperature and the surrounding concentration of chemicals cannot change much. Cells might shrivel up
like raisins or swell and burst. You can compare the maintenance of the cell’s environment to that of a
greenhouse. The internal environment of a greenhouse is maintained so that the conditions are favorable
for plant growth.
Not only do cells have to adjust to a changing environment, but they also have to adjust to the
activity of the moment. They may need to produce extra fuel to help your muscles run a race, they may
have to make your lungs and heart work harder, and they may have to release extra heat generated by the
hard work of these cells.
Keeping this delicate balance is called HOMEOSTASIS. This is a self-adjusting balance of all
the life functions and activities.
THE MOVEMENT OF MATERIALS
When we study cells, we are primarily concerned with the movement of molecules in a liquid. All
the substances important to life are often part of a solution. A solution is a mixture where the molecules of
one substance are evenly spread out in the molecules of another. The substance that makes up the greater
part of the solution (or the substance doing the dissolving) is called the solvent. The molecules in the
smaller amount (or the substance being dissolved) are called the solute. In salt water, water is the solvent
and the salt is the solute. Water is the solvent of most solutions involved in cell activities.
DIFFUSION is the process by which molecules of a substance move from area of higher
concentration to areas of lower concentration. Think of a drop of food coloring in a beaker of water. The
drop is initially very concentrated. Gradually the color molecules move throughout the whole beaker of
water until the entire beaker is the same color. The net, or overall, movement of the molecules results in a
uniform concentration of food coloring throughout the whole beaker. Diffusion is one of the major
mechanisms of molecular transport in cells. Many materials move into, out of, or through the cells due to
diffusion. The difference between the concentration of molecules of a substance from the highest to the
lowest concentration is called a diffusion gradient. Molecules move from the higher area of concentration
to the lower area along this concentration gradient. The steeper the gradient, the faster diffusion occurs.
OSMOSIS is how water diffuses into a cell. Osmosis is the diffusion of water through a
membrane. The cell membrane controls what enters and leaves the cell. They are selectively permeable.
This means they allow only certain substances to pass through them into or out of the cell. The cell
membrane is a lipid bilayer with proteins planted in it. Oxygen and carbon dioxide can pass right
through the membrane, but water cannot. Water and other molecules that cannot dissolve in lipids pass
through the cell through openings made by proteins in the membrane.
Water diffuses into cells by osmosis. Water makes up 70-95% of a cell. Since water is the most
abundant substance in cells, its movement into and out of the cell is very important. The cell has no control
over osmosis. It occurs due to differences in concentrations inside the cell and outside the cell. Water will
move back and forth across the cell membrane until equilibrium is reached. Water molecules will always
move to the area where they can make the water purer or “fresher”.
In an ISOTONIC
solution, the concentration of
solutes outside the cell is the
same as the concentration
inside the cell. They are equal.
Freshwater plants
often exist in HYPOTONIC
solutions. In hypotonic
solutions, the concentration of
solutes outside the cell is lower
than that inside the cell.
"“Hypo-"“means less than, so
there is less outside the cell.
As water flows into the cell,
the cell swells and increases its internal pressure. (The cell inside has less fresh water, so the fresh water
moves into the cell to try and make it more “fresh”.) This is called turgor pressure (pressure built up as a
result of osmosis). Excess water is often stored in the large central vacuole. The cell pushes against its cell
wall and the cell stiffens. This causes the plant to become more rigid.
In animal cells, if water flows in unchecked, the cell will swell and burst. An
example of this would be a red blood cell bursting when placed in fresh water. Cells
have ways to get rid of the excess water. Unicellular organisms have a contractile
vacuole which pumps excess water out of the cell. Freshwater fish remove excess water
through their gills.
In a HYPERTONIC solution, cells can shrivel up because more water flows out of the cell than
into it. In a hypertonic solution, the concentrations of the solutes outside the cell is greater than that inside
the cell. “Hyper-“ means more than, so there is more
outside. Drinking seawater is dangerous to humans
because the ocean is hypertonic with relation to the
human body. Drinking salt water causes the body’s
cells to lose water through osmosis. The cells lose
more than they take in.
OTHER MEANS OF TRANSPORT
Carrier molecules are proteins in the cell
membrane that transfer large molecules or molecules
that cannot dissolve in the lipids that make up the cell
membrane. They pick up molecules on one side of the
membrane and carry them across to deposit them on the
other side of the membrane.
Facilitated
diffusion involves the use of a carrier molecule but
follows the rules of simple diffusion – the molecules will move from an area of higher concentration to an
area of lower concentration. The carrier molecule speeds up the diffusion process. The cell does not
expend energy in this process.
Active transport is another transport method using carrier molecules. Active transport is the
movement of materials against the concentration gradient. In active transport, molecules are moved from
an area of low concentration to an area of high concentration. This process requires energy.
ORGANIC COMPOUNDS
There are six elements that are especially important to life: carbon, hydrogen, nitrogen, oxygen,
phosphorus, and sulfur (CHNOPS). There are about twenty others that play lesser roles. Iron, iodine and
other trace elements make up less than 0.1% of the human body, but must be present for the body to
function normally.
Carbon forms the backbone of all organic molecules. Only carbon is versatile and stable enough
to make up the tremendous variety of molecules that are found in living things. There are four main types
of molecules containing carbon.
CARBOHYDRATES are organic compounds that contain carbon, and hydrogen and oxygen.
Carbohydrates that you are familiar with are sugars and starches, such as glucose and cellulose.
Carbohydrates like cellulose are used as structural materials. Carbohydrates like glucose provide quick
energy or store energy in cells. The largest carbohydrates are called polysaccharides. These molecules
consist of hundreds of units of glucose or simple sugars. Plants store food in the form of starch, a
polysaccharide of glucose. Animals store excess sugars as glycogen, another polymer of glucose. Cells
break down glycogen or starch and energy is released.
LIPIDS are a chemically diverse group of substances that include fats, oils, and
waxes. Examples include butter, beef fat, and olive oil. Lipids also contain carbon,
hydrogen, and oxygen like carbohydrates, but lipids are more complex than
carbohydrates. All lipids are insoluble in water. They serve mainly as storage of energy
in living things. They provide the most stored energy and usually have the most calories.
Lipids are also part of the cell membrane and thus help regulate what enters and leaves
cells. Many lipids have a backbone that is a three-carbon molecule called glycerol to
which three fatty acids are attached.
PROTEINS are basic building materials of all living things. Protein molecules contain carbon,
hydrogen, and oxygen. But unlike carbohydrates and lipids, they also contain nitrogen, sulfur, and other
elements. All proteins are made of monomers (single molecules) called amino acids. Examples of proteins
include egg whites, gelatin, and hair. There are 20 amino acids. These amino acids combine to form
polypeptides. All proteins consist of polypeptides.
NUCLEIC ACIDS are a class of organic compounds that carry all instructions for cellular
activity. There are two kinds of nucleic acids. Deoxyribonucleic acid, DNA, records the instructions and
transmits them from generation to generation. Ribonucleic acid, RNA “reads” the instructions and carries
them out.
ENERGY FOR LIVING CELLS
Cells require chemical energy to make tasks necessary for life. This energy is stored in the
form of chemical bonds between atoms in food. The energy is taken from the food and stored in
molecules that can provide the energy where it is needed in the cell.
Many reactions in the body energy to keep them going (endergonic). In
most cases, a molecule called ATP (adenosine triphosphate) provides this
energy. ATP consists of a sugar, base, and a chain of three phosphates. The bond that
P
holds the second and third phosphate together is easily broken. Enzymes help ATP to
transfer this phosphate to another molecule. When this transfer takes place, energy is
released that drives the chemical reactions in a cell.
For ATP to be effective, it must lose its final phosphate. The phosphate is returned
to ATP by adding a phosphorus (P) to ADP. The series of reactions between
ATP and ADP form a cycle. See the diagram to the right. Think of it as a
battery that is continually recharging itself. The phosphate group is returned to
ATP during a process called cellular respiration. Glucose is broken down and
the energy in its bonds is transferred to the energy bonds of ATP.
PHOTOSYNTHESIS
The ultimate source of the energy that powers cells is the sun. Green plants and other organisms
(AUTOTROPHS) capture the light energy of the sun through the process of photosynthesis.
Photosynthesis requires light, chlorophyll, and raw materials. Enzymes are also needed for the reactions to
proceed. Chlorophyll in the plants traps the light of the sun. Carbon dioxide from the air and water from
the ground are the raw materials for the process of photosynthesis. Glucose is the end product. Oxygen
and water are also given off.
PHOTOSYNTHESIS
enzymes,
light, chlorophyll
6CO2 + 12H2O
C6H12O6 + 6O2 + 6H2O
The purpose of photosynthesis is to store the energy of the sun in the bonds of the glucose
molecules. These molecules are then used by organisms to provide energy for cellular activities. The
energy is removed from the glucose in a process called respiration.
RESPIRATION
Cellular respiration involves breaking the chemical bonds of organic food molecules and releasing
energy that can be used by the cells. The food molecules were the ones produced in plants during the
process of photosynthesis.
ATP
P
ADP
Respiration involves several steps. Glycolysis is the first step where glucose is broken down into
a compound, pyruvic acid, and energy for 2 ATP. From there, the pyruvic acid goes through Krebs cycle
and releases energy for 36 ATP. Glycolysis occurs in the cell’s cytoplasm and Krebs cycle occurs in the
mitochondria.
Respiration requires glucose and oxygen and it produces carbon dioxide, water, and energy.
enzymes
C6H12O6 + 6O2
6CO2
+ 6H2O + energy
The end result of respiration is the energy gain of 38 ATP.
Remember that plant and animal cells use ATP to run the chemical
reactions they need to survive.
DNA
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DNA is the genetic material of living things. It is contained in
the nucleus of most organisms.
DNA stands for DeoxyriboNucleic Acid. DNA contains three
parts - nitrogen bases, a five carbon sugar, and a phosphate
group. Each of these bases are attached to a sugar –
(deoxyribose), and a phosphate group. Each unit that includes
a base, sugar, and phosphate is called a nucleotide.
The nitrogen bases are called adenine, guanine, thymine, and cytosine.
DNA is shaped in a double-helix. A double-helix looks like a spiral staircase or a twisted ladder.
The sides of the helix are the phosphate groups and sugar molecules and the rungs on the helix are
the nitrogen-carrying bases.
The bases pair up in a specific pattern. Adenine always pairs with thymine and guanine always
pairs with cytosine.
The pairs of nucleotides that appear on the helix can appear in any order. The sequence of the
nucleotides is the code that controls the production of all the proteins of an organism. A
gene is a sequence of nucleotides that controls the production of a polypeptide (large protein) or an
RNA molecule. To give you an idea of size, all 46 of the human chromosomes are composed of
more than 5 billion nucleotides.
RNA
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RNA stands for RiboNucleic Acid.
RNA acts as a messenger between DNA and the ribosomes. If DNA is located in the nucleus
and the synthesis of proteins takes place in the ribosomes located in the cytoplasm, then there
must be a way for DNA to instruct the ribosomes in protein production without leaving the
nucleus. RNA is the way.
The sugar in RNA is ribose, not deoxyribose like DNA.
Also, uracil replaces thymine as a nitrogen base in RNA.
RNA is usually a single strand unlike DNA’s double-helix.
There are three types of RNA.
1. Messenger RNA (mRNA) carries the sequence of nucleotides from the DNA in the
nucleus to the ribosomes in the cytoplasm.
2. Transfer RNA (tRNA) picks up individual amino acids and brings them to the
ribosome. The amino acids are then joined together in proper order to form a
protein.
3.
Ribosomal RNA (rRNA) is contained in the ribosome and contributes to the
structure of it.
STORING AND TRANSMITTING INFORMATION
REPLICATION
Replication is the process in which DNA makes a copy of itself. Remember that each new cell
gets a copy of the genetic code. DNA replicates before cell division starts. During replication several steps
take place. The DNA upzips and then the bases pair up with the exposed nucleic acids. Each completed
DNA molecule contains one old strand and one new strand. ATP and the action of the enzymes power the
entire process.
TRANSCRIPTION
Transcription is the process whereby mRNA is copied from DNA. This process transfers the
DNA code to molecules of mRNA. Several steps occur. First, the DNA unzips. One strand of DNA
serves as a template for the RNA. The bases attach to the exposed nucleic acids. Once the RNA is made, it
detaches from the DNA and the DNA zips back up. The code in the mRNA allows the cell to collect the
right amino acids and assemble them in the correct sequence to make a particular protein. Each code is a
three letter word with a base standing as a letter. Each three letter code is called a codon.
TRANSLATION
The mRNA carries the codon information to the ribosome in the cytoplasm. Translation is the
process where the ribosome attaches to mRNA and carries out the formation of a protein. Several
ribosomes are involved in translation thus allowing one mRNA molecule to repeatedly produce a specific
protein molecule.
The ribosome is made up of two parts. The smaller part attaches to the mRNA.
The larger part contains a enzyme that helps to link amino acids together to form a
protein. The tRNA brings specific amino acids to the ribosome to be joined to a forming
protein strand. Each tRNA has an amino acid attached and an anticodon. The anticodon
pairs with a codon on the mRNA and thus amino acids are added in proper sequence.
MITOSIS VERSUS MEIOSIS
MITOSIS is a type of cell division, which generates two identical cells and DNA of the mother
cell. It occurs in body cells – somatic cells. Mitosis maintains the chromosome number and generates cell
replacement, maintenance, and repair of the organism. Mitosis requires one DNA replication and one
nuclear division.
MEIOSIS is a process in which the normal number of chromosomes in a cell is reduced by half or
a HAPLOID number. Chromosomes in cells occur in pairs called homologous chromosomes. Cells that
have homologous chromosomes are said to have DIPLOID (2n) number of chromosomes. Sex cells or
GAMETES must have a haploid number of chromosomes. When two gametes combine (sperm fertilizes
egg), then the cell has a full compliment of needed chromosomes.
Meiosis requires two cell divisions one after another. The DNA only replicates once. In Meiosis
I, the homologous (paired) chromosomes separate. During Meiosis II, the chromatids of each chromosome
separate. Meiosis I is just like mitosis.
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There are several stages involved in cell division:
INTERPHASE – this is the time between the formation of a cell through cell division and the
beginning of the next mitosis. DNA is replicated; more organelles and other structures are made.
PROPHASE – this phase takes up 60% of the total time for mitosis. During this stage, the
chromosomes coil up into short rods called chromatids. The nuclear membrane breaks down and
disappears. Spindle fibers appear between the centrioles and the chromosomes attach to the spindle
fibers at their centromere.
METAPHASE – Chromosomes become arranged along the cell’s equator or middle. Each
centromere is attached to a separate spindle fiber.
ANAPHASE – Each chromatid separates in each pair. Spindle fibers shorten and pull the two
chromatids apart. The single chromatids move to the opposite ends of the cell.
TELOPHASE – After the chromosomes have reached opposite ends of the cell, the spindle fibers
disappear. The nuclear membrane reforms and the chromosomes uncoil. The cell membrane pinches
together and a groove or furrow forms. The cell then separates into two daughter cells. This portion of
cell division is called cytokinesis. In plant cells, a cell wall forms in the middle of the cell and extends
outward to the cell membrane until it separates the two daughter cells.
During meiosis, the cell goes through this cycle twice. The only exception is that the DNA is not
duplicated before the second cell division. The result is four cells are formed, each with half the number of
chromosomes.
GENETICS AND HEREDITY
The study of HEREDITY is called GENETICS. Modern genetics is based on the knowledge
that traits are transmitted by means of chromosomes. Offspring resemble their parents because they carry
their parent’s genetic material in units called GENES. Genes are located on the CHROMOSOME; they
are the units of heredity. You have blue eyes because your parents gave it to you in their genes.
Gregor Mendel is the father of genetics and he studied the inherited traits in pea plants. He knew
nothing about chromosomes and yet he was able to discover the basic principles of heredity. Mendel had
logical experimental methods and he had careful record keeping. From his study, we can predict the
percent of characteristic traits that will be passed off to offspring.
Remember that you have traits from your mom and your dad. No one person is like any other
person in their genes except for identical twins, triplets, etc.
Here are some things you should know:
1. For each inherited trait, an individual has two copies of the gene – one from each parent.
2. There are alternate versions of genes – for example, blue, green, and brown eyes. These different
versions are called ALLELES. If the two alleles in a person are the same it is called
HOMOZYGOUS (such as TT or tt). If they are different, it is called HETEROZYGOUS (such
as Tt).
3. When two alleles occur together, one of them may be completely expressed, while the other may
have no observable effect on the organisms appearance. DOMINANT alleles are traits that
express themselves. RECESSIVE alleles are traits that are hidden. For every pair of traits, like
purple flowers and white flowers, one trait is always dominant and one is recessive.
4. The physical appearance of the trait is called the PHENOTYPE (example: brown eyes). The set
of alleles and individual receives is called the GENOTYPE (example: BB).
5. The PRINCIPLE OF DOMINANCE is when one gene in a pair prevents the other gene from
being expressed. A dominant gene masks another gene. A recessive gene is masked by a
dominant gene. Dominant traits are given capital letter and recessive genes are given lower case
letters.
B = brown
b = blue
BB = brown
Bb = brown
bb = blue
6.
The PRINCIPLE OF INCOMPLETE DOMINANCE is when one gene in a pair does not
prevent the other gene from being expressed. There is an intermediate trait shown. For instance,
snapdragons have red (RR) and white (rr) flowers, but with incomplete dominance, they can have
pink flowers (Rr). Neither red or white is completely dominant
THE PUNNET SQUARE
Let’s try a cross where there is complete
dominance. Seeds can have bumpy
shells or smooth shells. Bumpy is
dominant,
B and
smooth
is recessive,
b.
The Punnett
Square
is a grid
to help scientists
show all the possible gene combinations for a cro
Show the cross of BB and Bb in the box
to the left. What are the offspring?
Now let’s try is again with incomplete
dominance. Red (RR) are crossed with
white (rr) snapdragons. Show the cross
in the box to the right. What are the
offspring?
GENETIC DISORDERS
Abnormal chromosomes determine some human genetic disorders. Abnormalities can occur due
to NONDISJUNCTION. Nondisjunction is the failure of a chromosome pair to separate during meiosis.
When nondisjunction occurs, half of the gametes produced lack one chromosome and the other half have an
extra chromosome. Several serious problems result from cells with the wrong number of chromosomes (too
many or too few). Down’s syndrome can result from having three copies of chromosome 21 (instead of
just two).
Abnormalities and diseases can also be a result of MUTATION. The gene mutates (it has
different nucleic acids) and can no longer function normally. This abnormality can be passed onto the
offspring. Mutations result in diseases like sickle cell anemia, Huntington’s disease, and cystic fibrosis.
Colorblindness and hemophilia are sex-linked traits. These traits are carried on the ‘X’
chromosome. The mother acts as a CARRIER. She carried the defective gene but does not show the
disease. She can then pass the defective gene on to her children. If the child is a boy, then he will express
the disease because he does not have another “X” chromosome to mask the defect.
GENETIC ENGINEERING
Genetic engineering involves different approaches, but share the same four basic steps:
1. Cutting the DNA from an organism containing the gene of interest.
2. Making a combination of the original DNA fragment and DNA fragments from the organism that
is going to carry the new gene (both DNA together is called recombinant DNA).
3. Cells are treated to make many copies of the recombinant DNA.
4. Cells are then screened to remove the cells that did not take up the recombinant DNA.
This technique has been used to produce insulin and other needed drugs. Bacteria are given the gene
for the protein insulin and then the bacteria produce it. In addition, vaccines for diseases can be produced.
The genes for the disease-causing virus’ surface proteins can be inserted into a harmless virus and then put
into a vaccine.
DNA technology has been used to develop new strains of plants, which in turn can be used to
increase food crop yields. For example, by transferring genes for enzymes that are harmful to hornworms
into tomato plants, scientists can make tomato plants toxic to hornworms, and thus protect these plants
from these pests, which otherwise would seriously damage them
KINGDOMS OF ORGANISMS
Taxonomy
Scientists these days study chromosome structure, reproductive potential, biochemical similarities,
and embryology to determine the relationships among organisms. Organisms are then given classification
names. The classification levels are:
Kingdom-Phylum-Class-Order-FamilyGenus-Species
(to remember order, say: King Philip Came Over For Great Spaghetti)
For instance, here is the classification for a tiger: Kingdom Animalia, Phylum Chordata, Class Mammalia,
Order Carnivora, Family Felidae, Genus Panthera, Species tigris. The scientific name for tiger is Panthera
tigris.
Currently there are five kingdoms, but some scientists talk about six kingdoms. Six
kingdoms will be discussed here, although you should also know the five. In the five kingdom
arrangement, there is a kingdom Monera. In the six kingdom arrangement every kingdom is the
same except Kingdom Monera is replaced by Kingdom Eubacteria and Kingdom Archaebacteria.
KEY CHARACTERISTICS OF THE KINGDOMS
CHARACTERISTICS
EUBACTERIA
ARCHAEBACTERIA
PROTISTA
FUNGI
PLANTAE
ANIMALIA
CELL TYPE
Prokaryote
Prokaryote
Eukaryote
Eukaryote
Eukaryote
Eukaryote
CELL STRUCTURE
Cell wall, with
peptidoglycan
Cell wall, no
peptiodoglycan
Mixed
Cell wall,
chitin
Cell wall
No cell wall
BODY TYPE
Unicellular
Unicellular
Unicellular,
multicellular
Unicellular,
multicellular
Multicellular
Multicellular,
with organs
NUTRITION
Autotrophic
and
heterotrophic
Bacillus subtilis
Autotrophic
and
heterotrophic
Methanomicrobium
mobile
Autotrophic
and
heterotrophic
Euglena
gracilis
Heterotrophic
Autotrophic
Heterotrophic
Pennicillium
notatum
Pinus
radiata
(pine tree)
Loxodonta
Africana
(elephant)
EXAMPLE
The key characteristics listed above are explained below:
1. Cell Type: Organisms are either prokaryote or eukaryote. Two of the kingdoms are prokaryotic
and the other four include eukaryotes.
2. Cell construction: Cells are built differently. Some cells have cell walls made of different
compounds, and some cells have no cell walls at all.
3.
4.
Body Type: Organisms can be unicellular or multicellular and may have tissue or organs. Only
one kingdom includes organisms that have organs; organisms in the other kingdoms vary in body
type.
Nutrition: Organisms obtain their nutrition through photosynthesis or by heterotrophic means.
Some kingdoms have organisms that use both methods; but organisms in other kingdoms use
strictly one method.
EUBACTERIA
Characteristics:
Structures:
Growth:
Reproduction:
Beneficial:
Harmful:
Examples:
prokaryote, microscopic, lives as a single cell or in colonies in water. Most are
autotrophic (producers), a few are heterotrophic (consumers); have the same kind of
lipid (peptidoglycan) in their cell walls; found in practically every environment on
earth.
flagella, capsules
cell membrane and availability of food set growth limit; keep moist and warm for
optimal conditions
binary fission (splits in two)
decomposers of matter, in digestive system, nitrogen-fixers
can cause diseases like strep throat, pneumonia
Bacteria, blue-green bacteria
ARCHAEBACTERIA
Characteristics:
prokaryote, microscopic, lives as a single cell or in colonies in water. Most are
autotrophic (producers), a few are heterotrophic (consumers); do not have
peptidoglycan in their cell walls; found in extreme environments on earth – swamps,
hydrothermal vents, very salty places. Also found in soil and seawater. Most receive
their energy from inorganic sources.
Structures:
flagella, capsules
Growth:
cell membrane and availability of food set growth limit; methane (methanogens) and
sulfur (thermophiles) are two types of nutrients used for energy.
Reproduction:
binary fission (splits in two)
Beneficial:
unknown
Harmful:
unknown
Examples:
Methanogens, Thermophiles, Halophiles
PROTISTA
Characteristics:
Structures:
Growth:
Reproduction:
Beneficial:
Harmful:
Examples:
FUNGI
Characteristics:
Structures:
Most diverse kingdom; Animal-like organism, distinguished by method of
locomotion, eukaryotes, mainly microscopic, single celled or multicellular; some are
autotrophic (algae) and many are heterotrophic (protozoans); All single celled
eukaryotes are protists except yeast.
flagella, pseudopodia, capsules, cell organelles, membrane bound, some are
photosynthetic
cell membrane, availability of food set growth limit.
asexual or sexual
some are harmless
sleeping sickness, malaria
Most unicellular organisms - protozoa, amoeba, zooplankton, euglena, paramecium,
and algae
Animal-like organism, cannot move, eukaryotes, mainly multicellular, parasitic,
symbiotic, heterotrophic,
root-like, caps, filaments called hyphae
Growth:
Reproduction:
Beneficial:
Harmful:
Examples:
PLANTAE
Characteristics:
Structures:
Functions:
Systems:
Growth:
Reproduction:
Examples:
ANIMALS
Characteristics:
Structures:
Functions:
Systems:
Growth:
Reproduction:
Examples:
based on food source and availability; obtain nutrients by secreting digestive
enzymes into their environment and the absorbing the digested organic molecules.
asexual, sexual
yeast, penicillin, decompose organic material
cereal rusts, ringworm, athlete’s foot,
mushrooms, bread molds, slime molds, rusts and smuts, yeast
eukaryotes, mainly multicellular, can’t move, autotrophic
cellulose cell walls
based on cell and tissue chemistry
all present and functioning
determined by available nutrients
asexual, sexual by spores, seeds, flowers, and cones
All multicellular plants - Mosses, ferns, gymnosperms (pine cone plants),
angiosperms (flower-bearing plants)
eukaryotes, multicellular, heterotrophic, most are motile at some point in their
lifetime
all present and unique to the organism
based on nutrition, cell and tissue chemistry, and individual demands
all present and functioning
based on hormone action and nutrition
asexual, sexual
All multicellular animals - Invertebrates (sponges, jellyfish, coral, sea anemones,
planarian, fluke, tapeworm, hookworm, earthworm, mollusks, starfish, insects,
crustacean); vertebrates (fish – cartilaginous and bony); amphibians – frogs,
salamanders; reptiles – snakes, lizards, turtles; birds; and mammals
MORE ON PLANTS
One of the major ways that land plants differ is the way they transport water and nutrients
throughout the plant body. The majority of land plants have an internal system of connected tubes and
vessels called vascular tissues. These plants, called vascular plants, are the plants that you are the most
familiar with –maple trees, grasses, roses, and house plants. Vascular plants have roots, stems, and leaves.
The other group of plants lack vascular tissue. They transport water and nutrients by osmosis and
diffusion.
VASCULAR PLANTS AND THEIR TISSUES
Plants with vascular tissue have true roots, stems, and leaves. They have an internal network of
tubes that carry water, nutrients and glucose made from photosynthesis throughout the plant.
The ROOTS absorb water and nutrients from the soil and they anchor the plant.
The roots also store food that was made in the leaves. The STEM contains vascular
tissue that transports substances between the roots and the leaves. The stem also supports
plant growth above the ground. It is the backbone of the plant. There are two types of
vascular tissue: xylem and phloem. XYLEM transports water and minerals absorbed by
the roots up to those parts of the plant that are above the ground. The PLOEM carries
sugar and other soluble organic materials produced by photosynthesis from the leaves to
the rest of the plant.
The LEAVES use sunlight, water, and carbon dioxide to carry out photosynthesis. They also
transport the food they produce to the rest of the plant in a process called translocation. In addition leaves
exchange gases and water vapor with the atmosphere. The outside of the leaf is covered with a waxy layer
that slows the evaporation of water from the leaf. The leaf has openings called stomata. Each STOMATE
controls the exit and entry of water and gases. Most stomata are located on the underside of the leaf where
the surface is shaded. Ninety percent of the water that enters the roots is lost through the leaves in a
process called transpiration. The middle portion of the leaf contains the chlorophyll and other pigments.
The vascular plants can be divided into those that have seeds and those that have spores. Ferns,
horsetails, whisk ferns, and club mosses all have spores. All other plants have seed – either in a cone or in
a fruit.
DIFFERENT GROUPS OF PLANTS
Ferns are seedless plants that contain vascular tissue. Fern fronds
spread out over a large area and so ferns are able to survive in dim
sunlight.
Gymnosperms produce their seeds in cones and generally keep their leaves throughout the year
(evergreen). Conifers means “cone-bearer”. Pines, spruce, fir, and other conifers are characterized by
their stiff cones and needle-like leaves. Conifers can thrive in harsh conditions because they have special
adaptations. Their needles are covered in a hard waxy outer coating and have little exposed surface area.
This means that they do not lose much water. They shed their needles throughout the year instead of once a
year. They send their roots out into a wide area of soil instead of deep into the soil. This allows them to
survive in areas where the soil is not very deep.
Angiosperms are flowering plants. They produce seeds enclosed in fruits. (Gymnosperm seeds
are uncovered in their cones.) Angiosperms are deciduous plants. That means that they lose their leaves
every fall.
During pollination, pollen grains stick to the top of the stigma. From there, the pollen grain grows a
pollen tube down through the style to the ovary where it fertilizes the egg.
Animals, wind, and water all transport pollen from flower to flower. The nonessential flower
parts are modified to aid the specific type of pollination a plant undergoes. In flowers that are pollinated by
animals, the stem and receptacle hold the flower out where its colors and scent are most obvious. Some
flowers produce nectar, a sweet liquid.
Fruits are formed when the egg is fertilized and the ovary begins to swell and ripen. It changes
color and becomes fleshy or dry. Animals eat the fruit and pass the seed out to new places through their
waste.
SEXUAL REPRODUCTION IN FLOWERS
In plants that produce them, the flower functions in sexual
reproduction.
The parts are
as follows:
1. Stamen: male part of flower. Many
flowers have 3-5 stamens.
2. Filament: the thin stem-like portion of a
stamen.
3. Anther: pollen is produced at the tip of the
filament.
4. Pistil (labeled carpel in drawing): the
female part of the flower. Most flowers
5.
6.
7.
have a single pistil. The pistil contains three parts.
Ovary: The swollen base of the pistil. Within the ovary, one or more ovules produce the egg cells.
Style: The slender middle part of the pistil.
Stigma: At the tip of the style. The stigma produces a sticky substance to which pollen grains
become attached.
SEEDS
Seeds gave the animal world a new high-energy food source. They provide food for mammals
that need lots of energy to help maintain their body temperature. People have depended upon angiosperms
for food, lumber, fibers, clothing, and medicines.
The development of plants that have seeds really helped plants to survive in a variety of places.
Seeds can lie dormant (asleep) if the conditions aren’t right for growing. Some seeds, because they have
burrs or stickers, can travel a long way on animals or in the wind before falling to the ground and sprouting.
This spreading of seeds, called dispersal, is good for plants. It helps to spread the plant’s genes over a
wider area.
INVERTEBRATES
The major difference between animals and plants is that animals can move. Animals cannot
produce their own food so they must move to find it. The arrangement of body parts is related to how a
particular animal meets the challenges of living, which includes gathering food, protecting itself, and
reproducing. Differences in body structure are useful in classifying animals. Invertebrates make up 97% of
the animal kingdom. There are 15 invertebrate phyla and some of them will be discussed below.
PHYLUM PORIFERA
Sponges have the simplest body organization of any phlya. They have no head, mouth, or any
organized systems like digestion and circulation. The cells are not organized into tissues and organs. They
live in shallow seas. They are all shapes and sizes, as well as colors.
They do not move around, attaching themselves to a rock, shell, or other substance. They feed by
filtering food and nutrients out of the water. Their bodies consist of two layers of cells with a jelly-like
layer in between.
PHYLUM COELENTERATA
Coelenterates are bag-like animals with long flexible tentacles. Most live in seawater, but hydras
live in freshwater. Coelenterates include jellyfish, sea anemones, and corals. Coelenterates have a digestive
gut with only one opening. They have radial symmetry (Symmetry where body parts are arranged around a
central point - like a wheel.) Their bodies consist of two layers of cells, separated by a jelly-like substance.
They also have special stinging cells called cnidocytes.
PHYLUM PLATYHELMINTHES
This is the group of flatworms which includes the flatworm, the fluke, and the tapeworm. They
have a digestive cavity with only one opening. They have no circulatory or respiratory system. Flukes are
parasites and pose a serious health problem. Many can cause serious and even fatal diseases. They live off
the fluid of their host (blood or mucus). Most flukes are endoparasites which means they live inside the
body of their hosts. Their life cycle generally involves two or more hosts. For instance, the oriental lung
fluke infects crabs which are eaten raw by humans who then get infected with the worms. To not get
infected, humans could cook the crab meat! Tapeworms live in the intestines of vertebrates where they
feed by absorbing food that has already been digested by their host.
PHYLUM NEMATODA
This phylum includes roundworms, also called nematodes. Different types include Ascaris
(intestinal roundworm), hookworms, trichina, and pinworm. They have tubular bodies and have a digestive
tract open at both ends. Most roundworms are parasites. They feed on plants by sucking the juices from
them. They can infect humans, usually from poor sanitation and cause diseases. These roundworms are
pinworms, hookworms, or intestinal roundworms. Trichina infects pigs and can cause trichinosis in humans
who eat raw or undercooked pork.
PHYLUM ANNELIDA
This phylum is the segmented worms - they have bodies that are divided into a series of segments
which often look like visible rings on the outside of the body. They are also called annelids. They include
earthworms, leeches, and a variety of marine worms. They have three tissue layers and a body that has
bilateral symmetry (symmetry where body parts are identical on both sides – like humans). Annelids have a
true coelom (internal organs are suspended by double layers of a membrane). Annelids also have a more
complex circulatory, nervous, and respiratory systems than other worms.
PHYLUM MOLLUSCA
This phylum is the soft bodied mollusks. They live in fresh as well as seawater. They come in a
variety of sizes. Many are protected by one or more shells. They are classified according to what kind of
shell that they have. They include the two-shelled mollusks (clams, scallops, oysters), one-shelled mollusks
(snails) and no-shelled mollusks (squid, octopuses, cuttlefish). Mollusks have bilateral symmetry and they
have a true coelom. They have three distinct body parts - head-foot, visceral mass, and mantle. Clams
obtain both food and oxygen from the water that flows through their bodies. They are filter feeders. They
have gills that absorb the oxygen from the water. They have an open circulatory system and a three
chambered heart.
PHYLUM ECHINODERMATA
Echinoderms are spiny-skinned and include starfish, sand dollars, brittle stars, and sea urchins.
They live only in ocean/marine habitats. Echinoderms have an endoskeleton that is covered by a thin skin.
They are considered the most advanced form of invertebrates and are classified closest to vertebrates due to
a larva stage that is bilaterally symmetrical. They are radially symmetrical as adults. They have no brain.
They breathe through skin gills that are protected by the spines. The starfish has a remarkable ability to
regenerate body parts. So if a starfish loses an arm, it will regrow.
PHYLUM ARTHROPODA
The Arthropod phylum has more species than any other. Three quarters of all species on earth are
insects. Their great success is due in part to their body structure. They are characterized by having jointed
appendages, a segmented body, and an outer skeleton (exoskeleton). It is made of chitin. They have a well
developed open circulatory system with a long dorsal tube for a heart. The nervous system consist of two
long ventral chains of nerves and a simple brain.
The five major classes of Arthropods are insects (bees, beetles, mosquitos), arachnids (spiders,
scorpions, ticks, mites), crustacean (crayfish, lobsters, crabs, shrimp), Diplopoda (millipedes), and
Chilopoda (centipedes).
Insects are the only arthropods that can fly. They are both beneficial (pollination) and harmful
(crop destroyers). They have three distinct body parts and three pairs of legs. They include grasshoppers,
crickets, termites, aphids, flies, mosquitoes, butterflies, moths, beetles, ants, wasps, and bees.
VERTEBRATES
PHYLUM CHORDATA
This phylum is the most complex of all animals. The vertebrates (animals with backbones) make
up the largest subphylum in the phylum Chordata. At some point in their development, all chordates
possess four distinctive structures: a notochord, a nerve chord, gill slits, and a tail.
SUBPHYLUM VERTEBRATA
Vertebrates have a strong flexible backbone. Three classes live entirely in water - jawless fish,
cartilaginous fish, and bony fish. Amphibians are adapted to life on land as well as the water. Reptiles and
mammals are primarily land animals. All but a few birds can fly.
Vertebrates have a number of characteristics in common. They have bilateral symmetry. The
major sense organs are located in the head. All vertebrates have a closed circulatory system and a coelom
(large central body cavity that contains the important organs). They all have an endoskeleton which
supports and protects them. The endoskeleton can be made of cartilage or bone. A distinctive feature of
the skeleton is the backbone - vertebral column. They have pairs of muscles that work in opposite
directions to push and pull the bones.
Their bodies are covered with scales, skin, feathers, or hair. They have a digestive tube that goes
from mouth to anus. They have gills or lungs for breathing and have a closed circulatory system with two-,
three-, or four-chambered hearts. They have arteries to take the blood from the heart and veins to take it
back to the heart.
Their excretory (waste) system consist of kidneys, and associated tubes. Their nervous system
includes a spinal cord, brain, nerves, and sense organs. There are male and female sexes.
CLASS AGNATHA
They do not have jaws but use a sucker-like mouth to latch onto their prey. They have smooth,
cylinder-like bodies with flexible skeletons of cartilage. They are ectothermic (cold-blooded). The only
two surviving members of this class are the hagfishes and lampreys.
CLASS CHONDRICHTHYES
These are the cartilaginous fishes. Their skeletons are made of cartilage. They have hinged jaws
lined with rows of teeth. They are ectothermic. The class includes sharks, rays, and skates.
CLASS OSTEICHTHYES
Most of the world’s fishes are in this class. They have skeletons made of bone, and have jaws and
scaly skin. They get their oxygen from the water through gills. They are ectothermic.
CLASS AMPHIBIA
Amphibians live on land and in the water. They have internal lungs that are not very efficient and
they also get oxygen through their moist skin. They keep their skin moist with a mucus and they can never
venture too far from water. They return to the water to lay their eggs and their young pass through a larval
stage in the water before beginning their life on land. They are ectothermic. Amphibians include frogs,
toads, and salamanders.
In frogs, the young are called tadpoles and live in the water. The tadpole goes through
metamorphosis, or change, as it develops into an adult. A tadpole begins life with a short tail and breathes
through gills. Gradually it develops arms and legs and its tail begins to disappear. The lungs replace the
gills and the frog leaves the water.
CLASS REPTILIA
Reptiles were the first animals that were truly independent of the water. They do not need to keep
their body moist for their skin is thick and covered with scales. They do not need to return to water to have
babies for their young are laid in eggs. These eggs hold food for the embryo to live off of while it is
growing. They are ectothermic. Reptiles include the extinct dinosaurs, turtles, tortoises, alligators,
crocodiles, lizards, and snakes.
CLASS AVES
This is the class of all birds. Birds arose from reptiles and they grew feathers instead of scales to
insulate themselves. The feathers distinguish birds from other classes of vertebrates. Birds are
endothermic (warm-blooded) which means their body temperature remains constant.
CLASS MAMMALIA
Mammals have several characteristics not found in other vertebrates. They nurse their young
using milk from mammary glands. Mammals have live births - the young are born live after spending time
developing in their mother’s body.
They have body hair that acts as insulation and also protects the body from injury. Mammals have
a large well-developed brain and they are the only animals that have an external outer ear for hearing.
Their body is divided into two parts - the chest and the abdomen. The diaphragm separates the two parts.
They are endothermic.
Mammals include monotremes (duck-billed platypus, spiny anteater). They have mammary
glands which make them mammals, but they lay eggs. Mammals also include marsupials (kangaroos,
koalas, opossums). They bear live young, but the young are not as developed as other mammals. These
babies complete their development inside a pouch attached to the mother.
Placental mammals include 95% of all mammals. The embryo of a placental mammal is
implanted in the mother’s uterus - the mother’s reproductive organ. The placenta forms, connecting the
young mammal directly to the mother providing nutrients and oxygen.
ECOLOGY
Science Review
When studying for this portion of the test, be sure to review the following:
1. Analyze dependence of organisms on each other and the flow of energy and
matter in an ecosystem.
A. Evaluate relationships between organisms, populations, communities,
ecosystems, and biomes.
B. Describe the flow of matter and energy through an ecosystem by organizing
the components of food chains and webs.
Assessment will focus on the following:
1. Understanding the identifying characteristics of major biomes of the world on a
conceptual level, rather than identifying them on maps.
2. Describing predator-prey, producer-consumer, parasite-host, scavenging, or
decomposing relationships among organisms.
3. Understanding and analyzing the physical conditions (food, space, water, air, and
shelter) necessary for organisms to survive in an environment.
4. Understanding that the amount of matter remains constant as it flows through an
ecosystem.
5. Explaining the flow of energy through an ecosystem and that energy may change
from one form to another.
6. Using diagrams to interpret the interactions of organisms within food chains and
webs.
7. Determining the role of different organisms in food chains and webs.
Become Familiar with the following terms:
Heterotroph
Autotroph
Adaptation
Habitat
Niche
Food Chain
Food Web
Predator
Prey
Parasite
Decomposer
Host
Producer
Consumer
Population
Community
Ecosystem
Symbiosis
Parasitism
Herbivore
Carnivore
Omnivore
Biome
Tundra
Taiga
Temperate Deciduous
forest
Desert
Grassland
Tropical rain forest
Arid
ECOLOGY
ECOSYSTEMS
Life on earth extends from the ocean depths to a few kilometers above the earth’s surface. The
area where life exists is called the biosphere. The biosphere can be more easily understood by breaking it
into smaller components called ecosystems.
An ECOSYSTEM is a physically distinct, self-supporting unit of interacting organisms and their
surrounding environment. It is made up of biotic and abiotic interactions. The BIOTIC factors of an
ecosystem are the living organisms in the area. The ABIOTIC factors are the non-living, or physical,
components of the area like light, soil, water, temperature, wind, and nutrients. The essential factors that
make an ecosystem successful are a source of energy, a storage of water, and the ability to recycle water,
oxygen, carbon, and nitrogen.
Ecosystems must maintain an ecological balance. This can be helpful or harmful to the members
that make up the community depending upon whether they are predators or prey. A PREDATOR is an
animal that feeds on other living things. The animal it feeds upon is the PREY. Lions (predator) hunt
down and kill antelope (prey). Recently several state parks have allowed hunting for deer. The deer no
longer have a predator to keep their numbers down and so the parks are using man to do that. When there
are too many deer, too much of the forest and undergrowth are eaten and there is not enough food for all
deer to live a healthy life.
Each of the biotic organisms in an ecosystem interrelate with the others. A SYMBIOTIC
relationship between two members of a community is one in which one or both parties benefit.
PARASITISM is a relationship that involves a HOST organism which is harmed by the presence of the
other organism (fleas on dogs and cats). A parasite/host relationship is usually associated with diseases.
HIV is a virus that is a parasite living in the human body. A successful parasite learns to live in its host,
harming it but not killing it.
Natural resources are necessary for human survival and the making of necessary products. The
natural resources are water, air, soil, wildlife, and forests. Problems that are now being faced are related to
erosion, soil depletion, species extinction, deforestation, desertification, and water shortages. Efforts to
reverse these problems and their environmental damages are found in the planned programs of
reforestation, captive breeding, and planned farming through efficient plowing and planting procedures.
Disruptive changes can easily upset the stability of an ecosystem. Destructive acts of nature can
occur. A forest fire can destroy all plant and animal life in a forest, along a river, and around the shore of a
pond. It can also pollute a pond with ash.
Humans are unique in our ability to modify our ecosystem. Pollution from human acts can also
affect an ecosystem. A chemical spill or pesticides sprayed overhead can kill all plant and animal life with
which it comes in contact with. A housing development along the bank of a river or on the shore of a pond
can bring both garbage and noise pollution, in addition to direct physical destruction of these habitats.
COMMUNITIES
An ecosystem’s biotic factors interact with each other and compose a COMMUNITY of living
things that coexist. Each community is composed of populations. A POPULATION is a group of small
individuals of a single species that occupy a common area and share common resources. The number of
populations within a community varies. A tropical rain forest community may have thousands of
populations while a desert community may have very few.
Just like communities are made up of populations, each population is composed of interacting
individuals. Each individual organism lives in a specific environment and pursues a particular way of life.
The surroundings in which a particular species can be found is called its habitat. An organism can inhabit
an entire ecosystem like a woodpecker might occupy the whole oak forest. But the spider may only inhabit
the trunk of one of the oak trees.
The way of life that a species pursues within its habitat is called its ecological niche. An
organism’s niche is composed of biotic and abiotic factors. Some niches can be very broad (rats) while
others can be very limited (panda).
POPULATIONS IN ECOSYSTEMS
The population of an area is affected by the new offspring produced in the area. New plants and
animals moving in from other places increase the size of the population. The death of organisms and
animals moving out of the area decrease the size of the population. There is a direct relationship between
the number of plants and animals in an area which is in ecological balance. If the number of one of them is
increased or decreased, it will affect the numbers of the other. During deer season, the number of deer is
reduced by man. The plants that the deer eats will increase during this season.
A change in population may be helpful or harmful to the community. If insects are killed
by insecticide, the animals that depend on them for food
must move elsewhere. Even the human population changes
as the seasons change. In the summertime, the coastal area
is more widely populated by vacationing people. In the
wintertime, the snowy, mountainous areas are more
populated by snow skiers.
THE FLOW OF MATERIALS
Each ecosystem has its producers, consumers, and decomposers. Plants are called PRODUCERS
because they are able to use light energy from the sun to produce food (sugar) from carbon dioxide and
water. Animals cannot make their own food so they must eat plants and/or other animals. They are called
CONSUMERS and there are several types. HERBIVORES are animals that eat only plants.
CARNIVORES are animals that each only other animals. OMNIVORES are animals that eat both plants
and animals. DECOMPOSERS (bacteria and fungi) feed on decaying matter. Decomposers speed up the
decaying process that releases mineral salts back into the food chain for absorption by plants as nutrients.
All living things need energy to grow, energy to reproduce, energy to survive. All
ecosystems, therefore, need energy. Their energy begins
with the sun. Plants trap the solar energy and, through
photosynthesis, convert it into the sugars that are their food.
Animals eat the plants, taking some of that sun-harvested
energy into themselves. Other animals eat those animals.
Eventually, the animals die. Their bodies are cleaned off by SCAVENGERS and
dismantled by decomposers. A SAPROPHYTE is an
organism that feeds on dead organisms (a
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DECOMPOSER). For example, fungi use the nutrients in
dead leaves and other items on the forest floor for food.
The remaining minerals are returned to the soil, which is
enriched by them so that it is once again fertile and can
support new plants. Around and around it goes.
These relationships—which organisms eat which other organisms, and how the energy is
passed from one to another—can be thought of in terms of
an imaginary chain. In this chain, each organism forms a
single link: the chain stretches from the blackberries to the
mouse that eats one to the owl that catches the mouse. Such
an imaginary chain is known as a food chain. FOOD
CHAINS describe the flow of energy, in the form of food,
from one organism to another. Each organism forms a link
in the chain.
Almost all food chains begin with producers harvesting energy from the sun. From there the
energy is passed from producers to consumers: herbivores, carnivores, and omnivores. When these die the
energy passes to scavengers and decomposers, and back into the soil. Decomposers, as the last step to
replenishing the soil, are both the end and the beginning of any food chain.
We can see that, as with a real chain, removing any link causes the entire chain to collapse. If the
plants were removed, for example, it would not simply affect herbivores—for carnivores eat the herbivores.
If the decomposers were removed, the soil would not become replenished with minerals; new plants would
not grow; herbivores would not feed on them. And if the sun were removed from the chain—perhaps by
pollution blocking its light—nothing else on the chain would remain. The last living recipient of energy in
a food chain is called the “top consumer.” It will not be consumed itself until it dies.
Food chains are a helpful way to think about how energy moves through an ecosystem. In any real
situation, though, there are many different food chains, all connected to each other. A food web is a
diagram that combines food chains to show these connections. Food webs are made of interconnected food
chains.
These relationships can also be imagined as a pyramid, with plants on the bottom, then herbivores,
and then carnivores. This kind of diagram is known as an energy pyramid.
Energy is lost between every feeding level of an energy pyramid. Only about one-tenth of
the energy in plants flows to herbivores. One tenth of the
energy in herbivores flows to carnivores. The rest is used
up in the process of staying alive or lost as heat.
The most abundant organisms in any ecosystem, aside from decomposers, will be the producers.
Plants have the most energy available to them because they trap it directly from the sun. There will be
fewer carnivores and will be even fewer top carnivores. Small populations of top carnivores depend on
much larger populations of other animals to survive
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FOOD WEB
All organisms need certain chemicals in order to live. The most important ones are water, oxygen,
carbon, and nitrogen. The continuous movement of chemicals throughout an ecosystem is called recycling.
The amount of water or carbon in an ecosystem does not change, but the form of the water or carbon may
change. The water may be locked in ice or in a rain cloud and not in a lake or in the ground.
BIOMES
Communities are members of a larger ecological unit called a biome. A biome is an extensive
area of similar climate and vegetation. A biome’s abiotic (non-living) factors determine what plants and
animals live there. The major influences are temperature, light intensity, and patterns of rainfall which
determine the availability of water. There are six basic biomes on earth: tundra, taiga, grassland, deciduous
forest, desert, and tropical rain forest. You need to be able to understand these biomes and not just locate
them on a map.
Biomes that are closest to the poles experience the coldest weather conditions for they are furthest
away from the sun due to the tilting of the earth.
Biome
TUNDRA
high
Characteristics
the coldest biome
Temperature
very cold (32°F)
TAIGA
northern
the biome that sustains
cold (50°F)
Rainfall
light rainfall
medium rainfall
Location
high altitudes,
latitudes
occurs in
Evergreen trees, but is
climates or high
Pretty cold
mountains
up
DECIDUOUS
FOREST
Forest where trees lose
their leaves;
more temperate (75°F) medium rainfall
located in middle
latitudes
GRASSLAND
grasses and shrubs,
continents,
Few trees
water
more temperate (68°F) low rainfall
middle of
away from large
37
DESERT
very little vegetation
RAIN FOREST lots of plants and
near the
Trees; very diverse
hot during the day
(86°F) colder at night
very little rainfall
temperate (77°F)
heavy rainfall
sources
near the equator
or near mountain
ranges
usually occurs
equator
CHARACTERISTICS OF SCIENCE
Become familiar with the following terms:
Research problem
Hypothesis
Dependent variable
Independent variable
Variable
Experimental group
Control group
Conclusion
Accuracy
Prediction
Hypothesis
Data
THE SCIENTIFIC METHOD
Science is NOT just a body of knowledge; it is also something that people do to find out
about the world around them. Science involves observing the world and its events.
Scientists seek facts – try to solve deeper mysteries
Scientific Method:
Science is investigated by a logical process, sometimes called the scientific
method. This requires searching for an answer in an orderly, systematic manner. There is
not one order for the six steps, but it should be done logically.
1. State the Problem
Being curious; having questions about what you observe
2. Analyze the Problem (research the problem)
Gathering information; look for patterns; look at what
other research has done
3. Form a hypothesis
Hypothesis: educated guess on what you think will
happen
4. Test the hypothesis through experimentation
Experimentation; make sure you have a control and a
variable; test multiple times.
5. Record and analyze data
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Look at your data; look for patterns
6. Form a conclusion
Was your hypothesis true?; no theory can become fact
until it has been tested under all possible conditions;
Your hypothesis is not always true.
Sometimes, you can make a prediction about what will happen. This is an
educated guess based on past experience. You can also make an inference. An inference
is an implied answer based on indirect observations. For instance, you might record that it
rained today if you went outside after school and saw puddles on the sidewalk, but you
never actually saw it rain.
The Research Problem
Once the problem has been stated, the problem must be investigated. This is done
through research. The scientist searches the literature published on the problem,
interviews potential experts, and searches the Internet to find all the information available.
The problem must be restated so that only one variable is tested. Variables are the
specific factors that can be measured. The independent variable (manipulated variable)
is a set of conditions that will be changed by the researcher. The dependent variable
(responding variable) is the set of conditions that may or may not change as the
independent variable is changed. The dependent variable is the variable being tested.
The group of samples or subjects that is tested by changing a variable is the
experimental group. Another set of samples or subjects makes up the control group.
This group is EXACTLY like the experimental group, except that no variable has been
changed. The purpose of the control group is to verify whether or not changes occurred in
the experimental group and whether or not the changes were a result of the independent
variable.
The anticipated results are stated at the beginning of the experiment in the form of
the hypothesis.
Sample Research Problem 1
A student wishes to test the rate of photosynthesis in plants at different
temperatures. Elodea plants will be tested at different temperatures and the rate of oxygen
(O2) production will be measured.
Research Problem:
Does temperature affect the rate of oxygen production in
Elodea?
Independent Variable: ___________________________________
Dependent Variable:
___________________________________
Experimental group:
Set of plants ___________________________________
Control group:
Set of plants ___________________________________
Hypothesis:
Increase in temperature will increase the rate of O2
production
Sample Research Problem 2
A student wishes to find out if eating breakfast has any effect on reaction time.
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Research Problem:
Does eating breakfast affect reaction time of high school
students?
Independent Variable: ____________________________
Dependent Variable:
____________________________
Experimental group:
Students who
______________________________________
Control group:
Students who
______________________________________
Hypothesis:
Students who
______________________________________
Practice Section - Read the following and answer the questions that follow.
A. Mrs. Brim wants to find out why seawater freezes at a lower temperature than fresh
water.
B. Mrs. Brim goes to the media center and reads a number of articles about the physical
properties of solutions. She also reads about the composition of seawater.
C. She also travels to a nearby beach and observes the conditions there.
D. After considering all this information, Mrs. Brim sits at a desk and writes, My guess is
that sea water freezes at a lower temperature than fresh water because sea water has
salt in it.
E. She goes to her classroom lab and does the following:
1. Fills each of two beakers with 1 liter of fresh water.
2. Dissolves 35 grams of table salt into one of the beakers.
3. Places both beakers in a refrigerator whose temperature is -1°C.
4. Leave the beakers in the refrigerator for 24 hours.
F. After 24 hours, Mrs. Brim takes the beakers out of the refrigerator and looks at them.
She finds that the fresh water beaker is frozen and the salt water is still liquid.
G. She writes in her notebook, It appears as if the salt water freezes at a lower
temperature than fresh water does.
H. She continues, “Therefore, the reason seawater freezes at a lower temperature is that
sea water contains dissolved salts while fresh water does not.
Which statement contains the CONCLUSION?
_________
Which statement refers to GATHERING INFORMATION?
___________
Which statement contains the HYPOTHESIS?
___________
Which statement contains the TEST OF THE HYPOTHESIS?
___________
In which statement is the PROBLEM defined?
___________
Which statement contains the DATA in the experiment?
___________
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EXPERIMENTAL ERROR
Sometimes, it is helpful to determine if there is error associated with your
experiment. Sources of error can come from not doing the lab well (poor laboratory
technique), improper experimental set-up, and errors in data collection. You may be
asked to determine sources of error on the graduation test. Think of anyway that the
experiment could have been done wrong and this will lead to a source of error.
ANALYZING, EVALUATING, AND
PRESENTING INFORMATION
During the experiment, data and observations are recorded in a logbook. This data
then is analyzed in a variety of ways: data tables, graphs, etc. You must be able to read a
data table or graph and determine what it is trying to say. The analysis of the data is
summarized in a conclusion. The conclusion will state whether the hypothesis was
supported or rejected. The experiment should be repeated multiple times to verify the
accuracy of the data before stating the conclusion.
SAFETY EQUIPMENT AND RULES
Be familiar with the following safety rules for working in a laboratory:
1. Always wear goggles when working with flames or chemicals. This includes acids.
2. Never smell a chemical directly under your nose. Wave the odor from the bottle or
beaker towards your nose (called “wafting”). Remember that leaving a cap off of a
smelly chemical can cause the chemical’s smell to spread throughout the room in a
process called diffusion.
3. Be sure to use tongs to handle hot equipment. Use the back of your hand held close to
the item to determine if it is too hot.
4. When heating chemicals, make sure to point to opening of the test tube away from you
and your partner.
5. When lighting a Bunsen burner, light the match and then turn on the gas.
6. Know the location of the fire extinguisher, eyewash, first aid kit, and emergency
shower.
7. Be sure to read all directions before starting an experiment.
8. Report all spills and accidents to your teacher immediately.
Safety goggles should be worn at all times in the lab. It is the single most important
safety device. The fire extinguisher should be an ABC or BC type fire extinguisher.
PRESENTING DATA
The following are examples of ways to present data. Look at the following and answer the
questions that follow.
Bar Graph - shows how subjects compare in relation to the main topic.
Growth of Pea Plants
1. What information is given in this graph?
60cm
50cm
40cm
30cm
41
2. What week shows the highest growth rate?
3. What is the maximum height of the plant?
1 2 3
4
5
6
Weeks plant has been growing
Line Graph - is effective in showing trends, changes over time
Plant Height over 6 weeks
4. How tall was the plant the second week?
30cm
25cm
5. What period of time shows the greatest growth?
20cm
15cm
10cm
5cm
1 2 3
4
5
6
Weeks plant has been growing
6. If the growth continues at this rate, can you
estimate the height of the plant in the 7th week?
Circle Graph - shows how parts relate to a whole (percentages)
7. What is the total percent of a circle
graph?
8.
Why would a circle graph not measure
the growth of a plant?
9. If you have 500mL of atmosphere, how
many mL of nitrogen and oxygen are
there?
Nitrogen
and
Oxygen
78%
PROCESS SKILL PRACTICE
Analyzing an Experiment
42
Do Plants like Coca Cola?
Hypothesis: If ten plants are given Coca Cola and ten plants are given water, the plants
fed Coca Cola will be taller and have more leaves.
1. Independent variable:
__________________________________
2. Dependent Variable:
__________________________________
Experimental Set-up
Water
Coca Cola
X X X X X
X X X X X
X X X X X
X X X X X
X = individual plant
3. Which group is the control?
4. Why have a control group?
Name at least three factors that will be the same for both sets of plants.
Analyzing a Line Graph
Look at the graph and answer the questions below.
Temperature in Celsius
Beaker of Water Placed in the Freezer
70
60
50
40
30
20
10
0
-10
-20
-30
0
20
40
60
80
100
Time in Minutes
1. About what temperature is the water after 20 minutes has passed?
a. 50C
b. 43C
c. 35C
d. 24C
e. 15C
43
2. How long does it take for the beaker of water to reach a temperature of 0C
a. 10 minutes
c. 40 minutes
e. 70 minutes
b. 30 minutes
d. 50 minutes
3. After the beaker has been in the freezer for 70 minutes, its contents would most
probably be
all water at a temperature slightly above 0C
a.
all water at a temperature slightly below C.
b.
partly water and partly ice, all at a temperature of
0C.
c.
all ice at a temperature of 0C.
d.
all ice at a temperature slightly above 0C.
4. What happens to the temperature from 50-70 minutes?
a. The temperature increases
b. The temperature decreases
c. The temperature does not change
d. This information cannot be determined from this graph.
44
Interpreting a Data Table
DATA ON THE PLANETS
Planet
Mercury
Temperature K
Night Day
13
683
Surface
Pressure (atm)
1000
Radius
Earth radii
0.3819
Density
Earth Density
0.9554
Venus
233
720
15
0.9500
0.9524
Earth
275
295
0
1.000
1.000
Mars
170
300
0.006
0.5306
0.7188
Jupiter
123
313
10000
10.949
0.2422
Saturn
103
223
1000
9.1377
0.1246
Uranus
103
123
2
3.6837
0.2905
Neptune
103
123
7
3.5654
0.3790
Pluto
43
63
unknown
0.8946
0.2523
1. Which planet has the hottest temperature at night?
____________________
2. Which planet is nearest earth in density?
____________________
3. What are the radii of all the planets compared to?
____________________
5. List the planets in order of surface pressure with the greatest pressure first and the
lowest pressure last.
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Interpreting a Circle Graph
Below is a circle graph. The title of this graph is “Earth’s Surface.” Each segment has
a name and a percent value. Look at this graph, you can see that the pacific ocean covers
33% of the Earth’s
surface.
THE EARTH’S SURFACE
Indian Ocean
14%
Land
29%
Atlantic Ocean
16%
Artic ocean
3%
Other Seas
5%
Pacific ocean
33%
Try finding the following details on the graph above.
1. What percent of the Earth’s surface is land? ___________________
2. What total percent of the Earth’s surface is covered by the two largest oceans?
______________________
3. What total percent of the Earth’s surface is covered by water? ______________
4. By comparing the amount of surface covered by water with the amount of surface
covered by land, what would you say would be the key point made by this circle
graph?
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