Name:____________________________________________ Date:________________ Class#:_______________________
Ms. Desmarais
Science Review & Study Guide
Science All Around (Chapter 1; Section 1 &2)
A. Scientists are like detectives trying to solve mysteries.
a. Scientist gathers information and evidence in their search for answers to questions.
b. A hypothesis is an educated guess about a possible solution to a mystery.
B. Scientists use a problem-solving procedure called the scientific method; it includes identifying a
problem or questions, gathering information or researching, making hypotheses, testing
the hypotheses or experimenting, analyzing the results, and drawing conclusions.
C. Science is a process of observing, studying, and thinking about things to gain knowledge to better
understand the world.
a. Any attempt to find out how and why things look and behave the way they do is a
performance of science.
b. Earth Science is the study of Earth and space.
D. Testing, or experimenting, is an important part of science.
a. Variables are the different factors that can change in an experiment.
i. An experiment should be designed so that only one variable at a time is tested.
ii. The variable that changes, the one being tested in an experiment, is the
independent variable (X-axis).
iii. Constants are variables that do not change.
iv. A dependent variable (Y-axis) is the variable being measured.
b. A control is a standard to which results can be compared; the same experiment done with
the same variables, except it omits the independent variable.
E. For results to be valid or reliable, test should be repeated several times.
F. Observing and recording data and discoveries are important parts of an experiment.
a. Data and observations must be analyzed to draw conclusions.
b. Unexpected results may be important and should be recorded, as well.
G. Technology -use of scientific discoveries for practical purposes such as making pottery or
extracting metals from rocks.
a. Technology is transferable, meaning it can be applied to new situations.
b. Earth scientists and biologists use information form satellites to gather weather data
and track animals.
H. Scientific knowledge changes as testing procedures and instruments improve.
a. An explanation or model backed by results obtained from nay tests or experiments is
called scientific theory.
b. A scientific law is a rule that describes the behavior of something in nature, usually
without explaining why the behavior occurs.
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I. Science cannot answer all questions.
a. Ethics deals with moral values about what is good or bad.
b. Belief systems deal with religious questions that science cannot answer, such as: Do
humans have more value than other life forms?
J. It is important to prevent bias, or personal opinion, from influencing scientific observations.
a. Ethical and unbiased scientists keep detailed notes and allow other scientist to evaluate
their work.
b. Scientific fraud includes making up data, changing experiment results, or taking credit for
another’s work.
Cells – The Units of Life (Chapter 13; Section 1)
A. Cells help living creatures with activities of life such as movement, growth, and reproduction.
a. The cell theory was developed after Robert Hooke invented the microscope in 1665.
i. All living things are made of one or more cells.
ii. The cell is the basic unit of life.
iii. All cells come from cells that already exist.
b. Bacteria are one-celled organisms; larger organisms are made of many cells, sometimes
trillions of cells.
c. A microscope’s magnification is found by multiplying the powers of the eyepiece and the
objective lens.
B. Cells are composed of parts that do specific jobs.
a. The flexible cell membrane is the boundary of the cell and helps control what enters and
exits the cell; some cells have a cell wall that helps support and protect the cell.
b. Cytoplasm is a gelatin like substance containing many chemicals the cell needs.
c. Specialized cell parts called organelles do various jobs within a cell.
d. The nucleus contains hereditary material called chromosomes.
e. Vacuoles are storage organelles for food, water and wastes.
C. Inside the mitochondria cellular respiration uses oxygen to convert food energy into a form the
cell can use for energy.
a. Waste products of cellular respiration are carbon dioxide and water.
b. Leaf cells in plants contain chloroplasts that help the cell make its own food through
photosynthesis.
The Different Jobs of Cells (Chapter 13; Section 2)
A. The cells in many-celled organisms are specialized in shape and size fro their function.
a. Human specialized cells include fat cells, bone cells, nerve cells, and muscle cells.
i. Fat cells can store so much fat that the nucleus is pressed against the cell
membrane.
ii. Hard calcium and phosphors metrical surrounds bone cells.
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iii. Nerve cells have many long branches to send and receive messages.
iv. Muscle cells have fibers that can contract and relax.
b. Plant cells in leaves, stems, and roots are specialized to move food and water or to support
the plant.
B. Cells are organized so they can work together to keep the organism alive.
a. Tissues are groups of similar cells that do the same kind of work; two or more tissues that
work tighter to form an organ.
b. Groups of organs that work together to perform a job are called organ system.
c. A group of organ systems work together to form an organism.
Circulation (Chapter 15; Section 1)
A. Your cardiovascular system includes the blood, heart, and blood vessels. It moves materials to
all parts of your body.
a. Movement of materials into and out of your cells occurs by diffusion or movement of
materials from an area of high concentration to an area of low concentration.
b. Movement also occurs by active transport, which is the opposite of diffusion.
B. The Heart controls blood flow through all parts of the body.
a. The heart has four chambers:
i. Atriums - upper chambers
ii. Ventricles - lower chambers
b. Circulatory System is divided into three sections:
i. Coronary circulation is the flow of blood to and from the tissues of the heart.
ii. In pulmonary circulation, blood flows through the heart to the lungs, where
carbon dioxide and other waste materials diffuse out, oxygen diffuses in, and the
blood goes back to the heart.
iii. The Systemic circulation moves oxygen-rich blood to all the organs and body
tissues, except the heart and lungs, and returns oxygen-poor blood to the heart.
C. Blood vessels carry blood to every part of your body.
a. Arteries are blood vessels that carry blood away from the heart.
i. Arteries are rich in oxygen (oxygenated blood).
b. Veins carry blood back to the heart.
i. Veins are low in oxygen (deoxygenated blood)
c. Capillaries are microscopic blood vessels that connect arties to veins.
Blood (Chapter 15; Section 2)
A. Functions of blood
a. Blood carries oxygen from your lungs to your body cells, and carbon dioxide from your
cells to your lungs to be exhaled.
b. Blood carries waste products from cells to your kidneys to be removed.
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c. Blood transports nutrients your body’s cells.
d. Cells and molecules in blood fight infections and heal wounds.
B. Parts of Blood
a. Plasma - liquid part of blood.
i. Made mostly of water.
ii. Nutrients, minerals, and oxygen are dissolved in plasma.
iii. Carries wastes from cells.
b. Red blood cells supply your body with oxygen.
i. Red blood cells contain hemoglobin, which is a chemical that can carry oxygen and
carbon dioxide.
ii. The life span of a red blood cell is 120 days, and then rapidly replaced.
c. White blood cells fight bacteria and viruses.
i. Your body reacts to invaders by increasing the number of white blood cells.
ii. White blood cells enter infected tissues, destroy bacteria and viruses, and absorb
dead cells.
iii. The life span of a white blood cell is a few days to many months.
d. Platelets are irregularly shaped cell fragments that help clot blood.
i. Platelets stick to a wound and release chemicals.
ii. Threadlike fibers, called fibrin form a sticky net.
iii. The net traps blood cells and plasma and forms a clot.
iv. Skin cells then begin their repair process.
e. Blood types – A, B, AB, O
i. Based partly on antigens.
1. Chemical identification tags in the blood.
2. Type O blood has no antigens, and can donate blood to any type but can only
receive O type blood.
ii. Also based on antibodies
1. Proteins that identify substances that do not belong in the body such as
other blood types, and destroy them.
2. Type AB has no antibodies, so it can receive blood from any types
The Integumentary System (Chapter 14; Section 1)
A. Your skin is the largest organ of your body.
B. Skin is made up of three layers of tissue.
a. Epidermis - the outer, thinnest layer.
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i. New cells are constantly produced at the base of the epidermis.
ii. Cells produce melanin a pigment that protects your skin and gives it color.
b. Dermis - the middle layer.
i. The dermis is thicker than the epidermis.
ii. The dermis contains blood vessels, nerves, muscles, oil, sweat glands, and other
structures.
c. Fatty layer - insulates the body.
C. Skin has many functions.
a. Protection – forms a protective covering over the body that prevents injury and disease.
b. Sensory response - nerve cells in the skin detects and relay information to the brain.
c. Formation of vitamin D, which helps your body absorb calcium.
d. Regulation of body temperature.
e. Elimination of wastes through seat glands.
The Muscular System (Chapter 14; Section 2)
A. A muscle is an organ that can relax and contact, providing the force to move your body.
a. Voluntary muscles – muscles that you are able to control.
b. Involuntary muscles – muscles that you cannot control.
B. There are three types of muscle tissue.
a. Skeletal muscles move bone, are voluntary muscle.
i. Tendons are thick bands of tissue that attach muscle to bone.
ii. Ligaments are tough bands of tissue that connect bone to bone.
b. Smooth muscles – found in internal organs, are involuntary muscles.
c. Cardiac muscle – found only in the heart and is involuntary muscle.
The Skeletal System (Chapter 14; Section 3)
A. All the bones in your body make up your skeletal system, which has five major functions.
a. Your skeleton gives shape and support to your body.
b. Your bones protect your internal organs.
c. Major muscles are attached to your bones.
d. Blood cells are formed in the red marrow in the center of your bones.
e. Calcium and phosphorus compounds are stored in your skeleton for later use.
B. Bone Structure
a. Periosteum a tough, tight-fitting membrane that covers the bone’s surface.
b. Compact bone-the hard, strong layer under the periosteum.
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c. Spongy bone- found toward the ends of long bones.
d. Cartilage - a rubbery layer of tissue found at the ends of bones, where they form joints.
C. Before birth, your skeleton beings as cartilage, which is gradually broken down and replaced by
bone.
D. Joints – any place where two or more bones come together; bones are held in place by a tough
band of tissue called a ligaments.
E. Types of joints
a. Immovable joint – allows little or no movement.
b. Pivot joint- one bone rotates in a ring of a stationary bone.
c. Ball-and-socket joint – the rounded end of one bone fits into a cuplike cavity on another
bone.
d. Hinge joint – back-and-forth movement.
e. Gliding joint – one part of a bone slides over another bone; used the most in the body.
The Nervous System (Chapter 14; Section 4)
A. Your nervous system helps your body make adjustments to changes in your environment.
a. Stimulus-any change inside or outside your body that brings about a(n) response.
b. Homeostasis the regulation of steady condition inside an organism.
B. Neurons are made up of a cell body and branches called dendrites and axons.
a. Dendrites receive messages and send them to the cell body.
b. Axons carry messages away from the cell body.
c. The Central Nervous System (CNS) is made up of the brain and spinal cord.
d. The Peripheral Nervous System (PNS) connects your brain and spinal cord to the rest of
your body.
C. The somatic system controls voluntary actions.
D. The autonomic system controls involuntary actions.
E. Reflex – an involuntary, automatic response to a stimulus controlled by the spinal cord.
F. Your body has five senses.
a. Light enters your eye and stimulate the rods and cones, the cells found in your retina.
b. These send impulses to the optic nerve.
c. The visual area of your brain interprets the image and you “see”.
G. Hearing – when an object vibrates, it produces sound waves necessary for hearing sound.
H. Smell
a. Food and objects give off molecules that stimulate nerve cells, called olfactory cells.
b. The olfactory cells send impulses to the brain where the stimulus is interpreted.
I. Taste – taste buds on your tongue are the major sensory receptors.
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J. Touch – sensory receptors pick up changes in touch, pressure, pain, and temperature and send
impulses to the brain or spinal cord.
The Digestive System (Chapter 16; Section 1)
A. Digestion – breaks food down into small molecules that can be absorbed by blood.
a. Mechanical digestion – food is chewed, mixed, and churned.
b. Chemical digestion – chemical reactions break down food.
B. Enzymes
a. Type of protein that speed up the rate of a chemical reaction in your body.
b. Many enzymes are involved in the digestion of carbohydrates, proteins and fats.
C. Organs of the digestive system
a. Accessory organs – food does not pass through them
i. Include the tongue, teeth, salivary glands, liver, gallbladder, and pancreas.
D. Digestive tract
i. Mouth – here, your tongue, teeth, and saliva change food into a soft mass.
ii. Esophagus – muscular tube moves food to the stomach using peristalsis or waves
of muscle contractions.
iii. Stomach – Here, food is digested mechanically by peristalsis and chemically by
digestive solutions with the help of enzymes and hydrochloric acid.
Food becomes a thin, watery liquid called chyme.
iv. Small intestine - Villi increase the surface area to increase absorption. Blood
transports the absorbed nutrients to cell.
v. Large intestine – Absorbs water from undigested chime. The rectum and anus
control the release of solid wastes from the body.
Nutrition (Chapter 16; Section 2)
A. Your body needs nutrients found in foods.
a. Nutrients provide energy and materials for cell development, growth, and repair.
b. You need energy for every activity your body preforms.
B. Classes of Nutrients
a. Proteins
i. Used for replacement and replacement and repair of body cells and for growth.
ii. Made up of amino acids.
b. Carbohydrates
i. The main source of energy for your body.
ii. Sugars are simple carbohydrates; starch and fiber are complex carbohydrates.
c. Fats
i. Provides energy and help your body absorb vitamins.
ii. Classified as unsaturated or saturated based on their chemical structure.
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d. Vitamins and Minerals
i. Needed for growth, regulating body functions, and preventing some diseases.
e. Water
i. The human body is about 60 percent water.
ii. You lose water each day when you perspire, exhale, and get rid of wastes.
The Respiratory System (Chapter 16; Section 3)
A. Functions of the respiratory system – Supply oxygen to the body.
a. Breathing is the movement of the chest that brings air into the lungs and removes waste
gases.
b. Cellular respiration - oxygen is used by the cells to release energy from glucose.
c. The waste products of cellular respiration are carbon dioxide and water.
B. Organs of the Respiratory System
a. The pharynx is a tube-like passageway used by food, liquid, and air.
b. Air passes through the larynx, which contains the vocal cords used to speak.
c. Trachea tube held open by rings of cartilage; lined with cilia and mucous membranes.
d. At the lower end of the trachea, two short tubes called bronchi branch into smaller tubes.
e. Smallest tubes are bronchioles, which end in cluster of alveoli.
f. The alveoli are surrounded by capillaries; oxygen and waste products are exchanged
here.
C. Why do you breathe?
a. Signals from your brain tell muscles in your chest and abdomen to contract and relax.
b. Diaphragm - muscle that contracts and relaxes to move gas into and out of the lungs.
The Excretory System (Chapter 16; Section 4)
A. Functions of the excretory system – to remove body wastes.
a. Urinary system - gets rid of cell wastes in the blood and controls blood volume.
b. Organs of the urinary system.
i. The blood passes through filtering units of the kidneys called nephrons.
ii. Urine drains from kidneys to the bladder through tubes called ureters.
iii. The urethra passes urine out of the body.
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