CP Biology Midterm Review
Scientific Method
1. Define the following terms:
Independent variable
Dependent variable
Control
Constant variables
Quantitative Observation
Qualitative Observation
Variable being tested
Variable that is measured
What is kept under ‘normal’ conditions, to be used
to compare results
Variables kept the same to make experiment fair
Observations involving numbers
Observations without numbers
2. An experiment was designed to test the effect of sugar on the heartbeat of rats. Two groups of rats
were used. Every two hours rats from both groups were selected and their heartbeats were checked.
The rats of group one were given one dose of sugar five minutes before the heartbeat was checked.
a. Independent variable – dose of sugar
b. Dependent variable – heartbeat of the rat
c. Control – Group two without the sugar
3. List the steps of the scientific method in order and explain the steps.
Problem
Question to investigate AFTER making observations.
Research
Background information
Hypothesis
A testable prediction
Experiment
Step by step procedures to test hypothesis
Data
Charts, graphs, pictures collected during the experiment
Conclusion
Accept or reject hypothesis based on data
Basic Biology
1. What is the difference between an autrotroph and heterotroph?
Autotrophs are producers that make their own food by photosynthesis and then make ATP
through cellular respiration. Heterotrophs are consumers and can NOT make their own food.
They get food from eating plants and animals and converting this food into ATP by respiration.
2. What is metabolism?
Chemical processes that a body undergoes to maintain life: ingestion, digestion, respiration,
excretion.
3. List the characteristics of life. Something is LIVING if it has ALL characteristics.
a. Made of cells
b. Energy use/metabolism
c. Responds to the environment
d. Grows and develops
e. Reproduces
4. What is homeostasis?
Process of maintaining internal stability within an organism - Ability of organism to balance or
regulate itself (ex: not too hot, not too cold, just right)
Chemistry of Life
1. Define organic: organic compounds are made of carbon (hydrocarbons – hydrogens bonded to
carbons)
2. All living things are made up of 6 essential elements: CHONPS. Name the six elements of life.
Carbon
Hydrogen
Oxygen
Nitrogen
Phosphorous
Sulfur
3. Elements join together by chemical bonds to form compounds. Name 4 types of chemical bonds.
Ionic, covalent, polar covalent bonds, and hydrogen bonds (also peptide bonds in proteins).
4. Carbon is in all living things. How many bonds does carbon form? 4
5. There are 4 major categories of organic molecules that are made up of the CHONPS elements.
Complete the following chart on the “BIG 4”.
LIPIDS
Monomer: fatty acids and glycerol
Polymer: triglycerides (3 fatty acids bonded to
glycerol) and phospholipids (2 fatty acids,
glycerol, and phosphate group)
Function: 1. secondary energy storage, 2.
insulation, 3. phospholipids in building cell
membrane
Examples: fats, steroids like cholesterol, cell
membrane, waxes, saturated triglycerides are
animal fats (saturated means no double bonds
between carbons), unsaturated triglycerides are
plant oils
PROTEINS
Monomer: amino acids
Polymer: dipeptides, polypeptides, and proteins
are amino acids linked together by a peptide bond
CARBOHYDRATES
Monomer: monosaccharide (simple sugars like
glucose)
Polymer: polysaccharides (2 sugars joined by
dehydration synthesis reaction)
Function: major source of energy and plant cell
walls
Examples: sugars, starch (plant stored energy),
glycogen (animal stored energy in liver),
cellulose, plant cell walls
NUCLEIC ACIDS
Monomer: nucleotide (3 parts – 5 carbon sugar,
phosphate group, and nitrogen base)
Polymer: DNA and RNA
Function: 1. enzymes that speed up reactions 2.
structural proteins in hair muscle, skin, tendons 3.
antibodies that fight infection, 4) builds strong
muscles
Function: DNA that stores hereditary information
and RNA that builds proteins
Examples: enzymes, muscles, collagen, keratin,
antibodies, catalysts, hemoglobin
Reminder: DNA bases A bonds with T (apple
tree) and C bonds with G
Examples: DNA, RNA
6. Define chemical reaction: the process in which chemical bonds are broken and new ones formed,
producing one or more different substances
7. Write an example of a chemical reaction and label the reactants and products.
NaCl
→ Na + Cl
Reactants
products
8. What is the difference between hydrolysis and dehydration synthesis reactions?
Dehydration synthesis removes water and joins 2 monomers to make a polymer. Hydrolysis adds
water to break bonds of a polymer to form it back into its monomers.
9. Define enzyme – proteins that increase the speed of a chemical reaction
- each enzyme connects to a specific substrate (substance the enzyme reacts with)
10. Define activation energy – energy needed to start a chemical reaction
11. How does an enzyme affect the activation energy for a chemical reaction? Enzymes are catalysts
that reduce the activation energy needed for a chemical reaction to take place.
12. Any factors that affect the shape of an enzyme affect the enzyme’s activity. What effect does pH
and temperature have on an enzymes ability to catalyze (speed up) a reaction? Enzymes work well
within very specific ranges of pH and temperature. If the pH or temperature changes to outside of
the range (too high or too low), the enzyme shape changes and no longer works to speed up the
reaction.
5. Identify the hydrophilic and hydrophobic portions of a phospholipid.
Fatty acid tail are nonpolar and hydrophobic
Heads are polar and hydrophilic
6. What is the difference between active and passive transport?
Passive transport does not require energy and moves down the concentration gradient from an area
of high to low concentration. Active transport requires energy and moves against the gradient from
low to high concentration.
7. Explain how diffusion, osmosis, and facilitated diffusion work.
Diffusion
Osmosis
Hypertonic
Hypotonic
Isotonic
Facilitated
Diffusion
a type of passive transport across membrane that does not require energy,
particles move from high to low concentration
a type of passive transport across membrane that does not require energy,
WATER moves form area of high to low concentration
Water leaves cell because less water/more solute in the solution than inside
the cell
Water enters cell because more water/less solute in the solution than inside
the cell
Water goes in and out of cell equally
A type of passive transport across membranes that does not require energy,
the help of a carrier protein moves particles from high to low concentration
8. Explain the types of active transport. Protein pumps (3 Na out and 2K in) use ATP to pump ions
from low to high concentration or against the concentration gradient. Endocytosis uses ATP to
change cell membrane to enclose particles and make it ENter the cell. Exocytosis uses ATP to
change cell membrane to let particle EXit the cell.
9. Write the chemical formula for photosynthesis, aerobic cellular respiration, and anaerobic cellular
respiration.
C6H12O6 ------> lactic acid + 2ATP (lactic acid fermentation –anaerobic)
C6H12O6+ O2 -------> H2O + CO2 + 38 ATP (aerobic cellular respiration)
C6H12O6------>ethyl alcohol + 2CO2 + 2ATP (alcohol fermentation – anaerobic)
Sunlight + H2O + CO2 ------> C6H12O6 + O2 (photosynthesis)
10. Define photosynthesis: the process that captures the sunlight’s energy in the chloroplast of plant
cells and converts it to glucose
11. How does photosynthesis take place?
a. Light energy used to break water into H and O2 in the thylakoid of chloroplast during the light
cycle.
b. O2 leaves the chloroplast. H is attached to NADP to make NADPH.
c. CO2, ATP, NADPH enter dark cycle and H combines with the C and O to make glucose.
d. ADP and NADP returned to light cycle.
12. Define cellular respiration: the process that breaks down glucose to make 38 ATP for cells to use
as energy
13. Describe the steps to cellular respiration:
a. Glycolysis: splits glucose into pyruvic acid and release 2 ATP (happens in cytoplasm) of ALL
CELLS
b. Kreb’s Cycle: pyruvic acid is broken down into CO2 in mitochondria and form 2 ATP
c. Electron Transport Chain: electrons from Kreb’s cycle convert ADP into 34 ATP
14. How are photosynthesis and cellular respiration related? Cellular respiration is the opposite process
of photosynthesis.
15. What is ATP? Label the parts.
the cell
ATP is adenosine tri-phosphate and is the energy ‘currency’ of
16. What happens when a phosphate group is removed from ATP? Energy is released for the cell to
use and ATP becomes ADP.
ANATOMY and PHYSIOLOGY
1. Describe the levels of structural organization in the human body.
Cells → tissue → organ → organ system → organism
2. Complete the chart with the missing information.
Function: breaks
down and absorbs
nutrients from food,
removes waste,
maintains water
balance, used by cells
for
energy/repair/growth
DIGESTIVE SYSTEM
Path of Food:
Mouth - teeth mechanically break down food and amylase in saliva chemically
breaks starch into sugar
Pharynx – moves clump of food to esophagus
Esophagus – clump moves down tube by peristalsis (squeezing of esophagus)
Stomach – mixes the food and pepsin breaks down the proteins to form chyme
Small intestines – chyme mixes with enzymes from pancreas, liver, and
gallbladder to finish digestion and villi absorb nutrients from chyme
gallbladder to finish digestion and villi absorb nutrients from chyme
Large intestines – removes water from chyme
Rectum – removes waste
Circulatory System
Function: transports
Path of blood
Red Blood Cells –
nutrients and oxygen
Heart: pumps the blood to lungs and the rest of the carry oxygen though
and hormones to cells,
body
the body, contain the
removes waste
Arteries: carry oxygen rich blood from the heart to protein hemoglobin
the body (large)
which binds oxygen
Capillaries – bring nutrients and oxygen to the
in the lungs
tissues and absorb carbon dioxide and waste
Veins – carries oxygen-poor blood from body back
to heart
energy/repair/growth
Excretory System
Function of Kidneys: regulate the amount of
Function of Liver: secretes bile which helps
water and salt in the blood, remove waste as urine break down fats and absorb vitamins: regulates
sugar levels in blood
Function: move air into
and out of lungs,
controls gas exchange
between blood and
lungs, brings in oxygen
from air we breathe in
and releases carbon
dioxide when we
breathe out
Respiratory System
Path of oxygen/carbon dioxide:
Nose – filter, moisten, and warm air
Pharynx – controls movement of air into larynx and food into esophagus
Larynx – air moves through vocal cords to produce sound
Trachea – traps particles in air and push particles/mucus away from lungs
back to pharynx
Lungs – divides into smaller and smaller passageways until reach alveoli
Alveoli – tiny air sac that provide surface area for gases to exchange, oxygen
diffuses into blood from alveoli and carbon dioxide diffuses into alveoli
from blood
Function: collects info about
body’s internal and external
environment, regulates behavior,
maintains homeostasis, regulates
organs, controls sensory and
motor functions
Basic Unit – How does the
neuron work?
Neuron is made up of dendrites
that receive an electrical signal
which is then carried to the cell
body which is then carried
through the axon and passed
onto the next neurons dendrites.
Nervous System
Major Components:
Central Nervous System – brain and spinal cord
Peripheral Nervous System – contains sensory and motor neurons
Main parts:
Brain – control center responsible for processing and relaying
information
Spinal Cord – main communication link between brain and rest of
the body
Sensory Neurons –transmits info about internal and external
environments to the CNS
onto the next neurons dendrites.
Motor Neurons –transmits impulse from the CNS to the muscles
and glands
Muscular/Skeleton System
Function of Muscles: help in movement of bones, Function of bones: provides shape and support to
contraction of heart and other organs
the body, produce red and white blood cells in the
bone marrow
3 Types of Muscle Tissue & Their Function
2 types of connective tissue:
Skeletal – muscles that move bones
ligaments – attach bone to bone
Smooth – involuntary controlled like muscles that tendon – attaches muscle to bone
cause the stomach to contract
Cardiac – involuntary controlled – muscles that
makes heart beat
3. The organ systems of the human body work closely together to maintain the health of the entire
body. An organism who can not maintain homeostasis within all its systems will die. Explain how the
nervous system, muscular system, skeletal system, and circulatory system work together to help you
keep a constant body temperature when it is cold.
When it is cold out, the sensory neurons (nervous system) send a signal to the spinal cord then
to the brain. The brain interprets the signal and sends a message to the motor neurons. The motor
neurons trigger the muscles (muscular system) in your body to shiver and the muscles contract/relax
over and over again, which also causes the bones to move (skeleton system). This increases warmth in
the body. The heart (circulatory system) also beats faster sending warm blood more quickly throughout
the body to increase warmth.
4. What is a feedback loop?
Way to maintain homeostasis when internal or external conditions change. Example: body
sweats when too hot, liver stores excess glucose after a big meal and then releases the glucose
when needed