7th Science Review Packet KEY
Lab Safety, Metrics, Scientific Method, and Variables
1. How many mm long is the line below? 52 mm
_____________________________
2. How many cm long is the line above? 5.2 cm
3. Conversion practice:
a.
1.3 dm= .013 Dm
c.
2.4 KL= 2,400 L
b.
d.
13579 cg= .13579 Kg
17.24 mm= 1.724 cm
4. What piece of lab equipment would be best for finding the volume of 10 dimes? What about for finding the
mass of 10 dimes?
Volume- graduated cylinder, in order to preform water displacement (fill with a certain amount of water, place
the dimes in the cylinder and then measure how much the volume increased); Mass- a triple beam balance to
measure the mass of the dimes.
5. What is the volume of liquid in the graduated cylinder? 84 mL
6. What mass is shown on the triple beam balance below? 47.52 g
7. Circle and correct all unsafe practices that are happening in the picture below.
You should never eat or
Hair should be pulled back.
taste anything in the lab.
Chemicals should be
cleaned up after a spill
and kept where they
cannot spill.
Test tube should be
pointed away from
yourself and others.
Proper wear should be
worn to protect against
extreme temperatures.
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Goggles should be worn at
all times.
Use the written information and graph below to answer the next 3 questions:
The size of the U.S. population between the ages of 35 and 44 is shown on the line graph below. Use the population
data for people between the ages of 14 and 17 given in the table to the right of the graph to plot a comparison line
on the graph next to the line that is already there.
U.S. Population
Between the Ages of
14 and 17
Population
Year
(thousands)
1960
11,219
1970
15,924
1980
16,142
1990
13,311
2000
15,752
8. Which of the 2 age populations changed the most, the 35-44 year-olds or the 14-17 year-olds? 35-44 year olds
9. During which time span did the younger generation’s population decrease? 1980-90
10. During which time span did the older generation’s population decrease? 1960-70
11. What is the difference between an independent and dependent variable?
The independent variable is the variable that is changed on purpose by the experimenter (x axis).
The dependent variable is the variable that responds to the independent variable, it is measurable (y axis).
READ the following. Then answer questions 12-16 by circling the letter of your choice.
Vitamin C is important for a variety of health reasons. Your body does not store Vitamin C, so it is necessary
for you to take it in every day. Fruit juices are generally considered a good source of Vitamin C, but with so many
fruit drinks available, which juice is the best source of Vitamin C?
An experiment was conducted in which 6 test tubes were used. Each was filled with an equal amount of
liquid to be tested for the presence of Vitamin C. A blue indicator solution was added a drop at a time. The
quicker that the liquid turned colorless means that there is more Vitamin C present. If the liquid has not become
colorless after 20 drops had been added, it was assumed that that liquid contained no Vitamin C. The results are
shown in the chart below.
Tube #
Test Liquid
Number of Drops Added
1
Water
20
2
Orange Juice
5-6
3
Pineapple Juice
12
4
Apple Juice
20
5
Tomato Juice
7-8
2
6
Cranberry Juice
20
12. What problem was investigated in the experiment?
A. Which solution can be used to indicate the presence of Vitamin C?
B. How much Vitamin C is present in certain juices?
C. Which fruit juice had the greatest amount of Vitamin C?
D. Which fruit juice costs the most per unit of Vitamin C?
13. Which of the following was the control group?
A. Water
C. Apple juice
B. Orange juice
D. Cranberry juice
14. Which of the following would you conclude to have the least amount of Vitamin C per mL?
A. Orange juice
B. Tomato Juice
C. Pineapple juice
D. Apple and Cranberry juice
15. If another juice was tested and the indicator became colorless after 4 drops were added, you could
conclude that
A. it had more Vitamin C than the other juices tested.
B. orange juice has slightly more Vitamin C.
C. the juice has less Vitamin C than the other juices tested.
D. The indicator solution had been contaminated with one of the other juices.
16. Which of the following was the dependent variable?
A. Test liquid
B. Tube #
C. Number of drops
D. The water
17. Squidward loves playing his clarinet and believes it attracts more jellyfish than any other instrument he has
played. In order to test his hypothesis, Squidward played a song on his clarinet for a total of 5 minutes and counted
the number of jellyfish he saw in his front yard. He played the song a total of 3 times on his clarinet and repeated the
experiment using a flute and a guitar. He also recorded the number of jellyfish he observed when he was not
playing an instrument. The results are shown in the chart.
18. What is the independent variable?
Musical instrument played
19. What is the dependent variable?
Number of jellyfish attracted
20. What should Squidward’s conclusion be?
Overall, it seems that the clarinet attracted more
jellyfish than any other instrument.
21. Are the results reliable? Why or why not?
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Yes, he completed more than one trial for each of the instruments; the length of time, person playing the instrument
etc. stayed the same, so there shouldn’t have been any other factors to consider.
Microscopes, Cells, and Diffusion
22. How do you calculate the power of magnification on a microscope?
Multiply the eyepiece magnification by the objective lens magnification.
23. How do you correctly carry a microscope?
One hand under the base, one hand holding the arm
24. What is the difference between a wet mount and a prepared slide?
You prepare a wet mount using a slide, water, and a cover slip. Prepared slides are made for
you and can only have non-living specimen.
25. Label the diagram of the microscope AND briefly describe each part’s function.
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25. (cont.)
-
Eyepiece: magnifies the image
Body Tube: image of the specimen travels through this to the eyepiece
Nosepiece: holds the objective lenses, can rotate to use different magnifications
Objective Lens: magnifies the specimen
Stage: Holds the slide
Stage Clips: holds the slide in place on the stage
Diaphragm: controls how much light is let through
Coarse Adjustment Knob: moves the stage up and down
Fine Adjustment Knob: focuses the image
Base: Holds the microscope in place
Arm: Supports the nosepiece and body tube
26. What are the three parts to the cell theory?
•
•
•
All living things are made up of cells.
Cells are the smallest working units of all living things.
All cells come from preexisting cells.
27. What is a cell?
 Cells are the building blocks of life. A cell is the smallest thing that is considered ALIVE.
28. Label the following cell parts on the cell AND describe each organelle’s function:
Nucleus
A. Nucleus- directs cell activities
B. Cytoplasm- hold all organelles in place (space)
C. Cell Membrane- Outer membrane of cell that
controls movement in and out of the cell (outer layer)
D. Mitochondria- produce energy through chemical
reactions (breaking down fats & carbohydrates)
E. Ribosome- make proteins (Dots)
F. Vacuole- store water and items for digestion, and for
waste removal (not pictured)
G. Endoplasmic Reticulum- moves materials around in cell
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Lysosome:
Responsible
for immunity
and digestion
H. Golgi Body- modify and package proteins so they
can be transported in and out of the cell
29. What is the difference between a unicellular and multicellular organism?
Uni = 1, Multi = many
unicellular = 1 celled organism, multicellular = an organism with many cells
30. List the levels of organization, from cells all of the way to organisms.
Cells tissuesorgansorgan systemsorganisms
31. List the organelles that ONLY plant cells have and describe their functions:

Cell Wall: Extra layer of support and protection

Chloroplast: uses sunlight to make sugar
32. Describe diffusion:
When molecules move from an area of high concentration to an area of low
concentration
33. Describe osmosis:
Diffusion of water across a membrane (example: water moving into a cell)
34. Give an example of diffusion in everyday life.
You can smell Thanksgiving dinner from your room upstairs
35. Molecules diffuse because they are constantly trying to reach a state of Equilibrium.
DNA & Genetics
Define the following genetics terms using your own words- not definitions straight from the glossary.
36. Allele – different versions of a gene
37. Dominant – expressed allele (overpowers and covers up recessive allele, if present) – represented by
uppercase letter
38. Recessive – unexpressed allele (covered up by dominant gene) – represented by lowercase letter
39. Heterozygous – two different alleles (one dominant and one recessive) - hybrid
40. Homozygous – two same alleles (two dominant or two recessive alleles) - purebred
41. DNA – deoxyribonucleic acid; a very long molecule that contains a code
42. Gene – a small section on a strand of DNA
43. Heredity – how you inherit traits
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44. Trait – physical characteristic that you see
45. Genotype – the genes of an organism; for one specific trait we use 2 letters to represent the genotype
46. Phenotype – the physical appearance of a trait in an organism; for one specific trait we use words to
represent the phenotype; example: blue eyes, brown eyes
47. How many chromosomes do human sex cells (sperm & egg) have? 23
48. How many chromosomes do all other human body cells have? 46
49. What 4 bases are in DNA and how do they pair? Adenine pairs with Thymine; Cytosine pairs with Guanine
50. What 2 molecules make up the sides of DNA?
a. sugars
b. phosphates
51. What DNA strand would be paired with this strand?

ATGGCT TCGGAGC
TACCGAAGCCTCG
52. Describe and sketch the relationship between chromosomes and chromatin
Chromosomes are
condensed DNA,
while chromatin is relaxed DNA.
53. Describe DNA’s shape and sketch it. Double helix
54. How is your genotype related to your phenotype? genotype causes your phenotype
55. Why do cells divide?
 They get too big
 It wants to make sure its DNA will be passed on
 Replace worn out cells
56. Compare and contrast sexual and asexual reproduction.
Asexual
Sexual
-all genetically identical; no variation
-all genetically different offspring
-DNA 100% of parents; clones of the parents
-offspring receives ½ the DNA from mom and ½ from dad
-only requires 1 parent organism
-requires 2 organisms to reproduce
57. Complete the following genetics problems.
A. In sweet pea plants, round seeds (R) are dominant to wrinkled seeds (r).
Fill in the square below for a homozygous recessive plant crossed with a heterozygous plant.
r
r
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R
Expected genotypes (%)? 50% Rr; 50% rr
r
Rr
Rr
rr
rr
Expected phenotypes (%)? 50% round seeds; 50% wrinkled seeds
B. In purple people eaters, one-horn is dominant and no horns is recessive. Follow the four steps, showing a
cross of a purple people eater that is heterozygous for horns with a purple people eater that is homozygous
recessive. Summarize the genotypes & phenotypes of the possible offspring.
H
h
Expected genotypes (%)? 50% Hh; 50% hh
h
Hh
hh
Hh
hh
Expected phenotypes (%)? 50% one horned; 50% no horns
h
C. In silkworms a single gene determines the color of the cocoon. The Yellow cocoon allele is dominant. It is
indicated by "C". The white allele is recessive, and indicated by "c". Complete the following Punnett Square
assuming a homozygous dominant male (CC) crosses with a homozygous recessive female (cc).
Expected genotypes (%)? 100% Cc
c
Expected phenotypes (%)? 100% yellow cocoon
c
C
C
Cc
Cc
Cc
Cc
58. When fertilization in human cells occurs, how is the sex of the offspring determined? The sex of the offspring is
determined by the male parent. If the dad passes on an X chromosome, then the offspring will be a girl (XX),
because it will have an X from dad and an X from mom. If the dad passes on a Y chromosome, then the
offspring will be a boy (XY), because it will have an X from mom and a Y from dad.
59. Where is DNA located in most cells? in the nucleus
60. In genetics, can you ever be 100% certain of a person’s genotype by just looking at their phenotype?
Why or why not? Yes, if the person is expressing the recessive trait then you know that their genotype must be
homozygous recessive for that particular trait.
61. What does genetic diversity mean? Which type of reproduction produces the most genetic diversity
amongst its offspring? WHY? Genetic diversity means that there is variety in the offspring’s DNA. Sexual
reproduction produces the most genetic diversity amongst its offspring.
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Human Body Systems: Skeletal, Muscular, Digestive, and
Excretory
62. How is your skeletal system like a factory? Our bones make blood cells for our body!
63. How is your skeletal system like a storehouse?
Our bones store fats, minerals, calcium and water for our body.
64. Beginning at the inside of a bone, what are the four layers of bone?
a. bone marrow
b.
spongy bone
c.
compact bone
d. periosteum
65. Which part of the bone is the strongest?
Compact bone because it is more dense.
66. Why do birds have more spongy bone than humans? Spongy bone is not as dense, it helps them be light
enough to fly!
67. What are the 5 functions of the skeletal system?
a. to provide shape and support for the body (framework analogy)
b. to protect our organs
c. to work with the muscular system
d. to make blood cells (factory analogy)
e. to act as a storage for fats, calcium and other minerals (storehouse analogy)
68. Define the words listed below:
A. periosteum – outmost layer of the bone
B. bone marrow- where blood cells are made, inner most layer of the bone
C. ligament – connect bones to other bones for support
D. joint – where two or more bones meet
E. tendon – to connect muscles to bones
F.
cartilage – cushion or shock absorber, found between two bones
69. What is the difference between involuntary and voluntary muscles?
Involuntary muscles contract and relax without our control, while voluntary muscles we can control and move
consciously.
70. Give an example for each of the following muscle types:
b. Involuntary, Cardiac = heart
c. Voluntary, Skeletal = arms, legs etc.
d. Involuntary, Smooth = esophagus, stomach, small intestine etc.
71. What is the main function of the digestive system?
To break down food so that our bodies can use it!
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72. Name, in order, the organs through which food passes as it moves through the digestive tract:
a. mouth
b. esophagus
c. stomach
d. small intestine
e. large intestine
f. rectum
g. anus
73. Explain why your stomach lining is not digested by the acid in the stomach.
The stomach has a protective layer of mucus lining its walls that prevent the acid from begin digested.
74. What substance is made by the liver and stored in the gallbladder?
Bile
75. What is the function of this substance?
To aid in digestion by breakdown the fats in foods.
76. What do the pancreas, liver, and gallbladder have in common?
They’re all accessory organs and they DO NOT have food pass through them. They play an important part to
digestion by secreting additional substances that help break down food.
77. What is chyme and where is it produced?
Chyme is a watery soup of food and digestive juices, produced in the stomach.
78. What is the difference between mechanical and chemical digestion?
Mechanical digestion is where food is broken down in to smaller pieces (by the teeth, in the mouth). Chemical
digestion is the breakdown of food, but with chemicals or enzymes added to it (ex.: salivary glands).
79. What is the main function of the excretory system?
Excretory system’s job is to remove waste from the body.
80. What are the 4 ways in which wastes are excreted from our bodies?
a. liquid waste through sweat glands
c. solid waste through the large intestine
b. liquid waste through the urinary system (kidneys etc.) d. gaseous waste though the lungs
81. What is the function of the small intestine?
To absorb nutrients for the body.
82. What is the function of the large intestine?
To absorb extra water and minerals, not absorbed in the small intestines.
83. If the small intestine is longer than the large intestine why are the names
not switched?
The names are about the WIDTH of the intestines, not the length. The small
intestine is 2.5 cm wide, while the large intestine is 6 cm wide.
84. What is the function of the Urinary System?
The urinary system’s job is to filter waste out of the blood.
85. Label the 4 major parts of the Urinary System and describe their functions:
a. kidneys- kidney bean shaped organs, about the size of your fist, filter waste/urea out of the blood
b. ureters- long, thin tubes that carry urea down from the kidneys to the bladder
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c. bladder- a hollow, muscular, balloon shaped organ that expands and relaxes as it is filled and emptied.
d. urethra- shot tube exiting the body, how urea leaves the body
Human Body Systems: Circulatory, Respiratory, Nervous,
Integumentary, Endocrine, and Reproductive Systems
86. In terms of circulation, why does the heart pump?
So that oxygenated blood can be pushed to the rest of your body (because your cells need the oxygen)
87. What happens if your heart stops? Oxygenated blood does not get pushed out to your cells, and you can die
very quickly.
88. What are the 3 parts of the circulatory system?
-Heart
-Blood
-Blood vessels
89. Describe the human heart. (refer to notes if needed)
- muscular pump
-has 2 sides (right side pumps blood to lungs to get O2;
while left side pumps oxygenated blood out to
to the rest of the body
-each chamber is separated by valves that open and
close with each contraction
90. Label the diagram of the heart on the right.
91. Describe the following blood vessels:
a. Artery- carries blood AWAY from heart
b. Vein- carries blood back TO the heart
c. Capillary- tiny blood vessel where gas exchange happens
92. Why does your heart have to pump your blood to your lungs before it can pump it to the rest of your body?
The heart has to send the blood to the lungs to get the oxygen, before it can send the blood out to the body
cells.
93. What two gases are exchanged through your respiratory system?
O2 enters the blood in the lungs, and CO2 leaves the blood and enters the lungs
94. Which one do you exhale?
CO2
95. Starting with your nose and mouth, list all structures through which air travels from the time you inhale until
oxygen molecules actually diffuse into your bloodstream.
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Mouth and Nose  __Pharynx____  ____Trachea___  ____Bronchi___  _____Bronchioles___ 
___Alveoli_____  Blood stream
96. What is the diaphragm? The large
controls breathing
muscle underneath your ribcage
97. How does the diaphragm control
and relaxes to push air out.
breathing? It contracts to pull air in,
98. Label the diagram using the words artery, capillaries, and vein.
Artery
Vein
Capillary
99. Fill in the blanks:
Air is inhaled through the mouth and nose, where is goes through the pharynx and past the larynx. It goes down a
long pipe called the trachea until it splits into 2 bronchi. The air goes into both of these pipes, and into the smaller
tubes called bronchioles. These tubes eventually end in the alveoli, which is where gas exchange occurs. This is when
O2 is dropped off into the capillaries and CO2 is picked up and eventually exhaled.
100.
Label the three layers of skin.
Epidermis
Dermis
Subcutaneous Layer
101. List the 6 functions of the Integumentary System: (refer to notes)
a. Protecting the underlying tissue
b. Regulating internal body temperature
c. Collecting sensory information from the environment
d. Producing some vitamins
e. Retaining necessary fluids
f. Eliminating some wastes
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102. What 3 body systems are involved in a reflex reaction and how each is involved?
a. Integumentary- skin has receptors that receive information from the environment
b. Nervous- neurons send information to spinal cord and decide how to react
c. Muscles- react by contracting or relaxing when they receive message from motor neuron
103.
How do nerve messages get from one nerve cell to another when nerve cells don’t even touch each other?
The chemical messages jump across the synapse.
104.
What makes up the central nervous system? Brain & Spinal Cord
105.
What makes up the peripheral nervous system? All of the other nerves in your body
106.
Where in the nervous system are reflex responses controlled? In the spinal cord (the brain is NOT involved!)
107.
Describe what each section of the brain is responsible for.
a. Cerebrum- all conscious body processes (senses, thought, learning, memory, emotions)
b. Cerebellum- movement & coordination
c. Brainstem- all body processes necessary to survive (heart rate, breathing, digestion, etc)
108.
Define/describe the following terms associated with reproduction.
A. Asexual - method of reproducing that involves one parent
B. Sexual – method of reproducing that involves 2 parents
C. Fertilization – the joining of the sperm and egg cells
D. Zygote – an egg cell that has been fertilized by a sperm cell
E. Embryo – a zygote that has implanted itself in the uterus and starting to develop further
F.
109.
Fetus – a baby
Which organs produce sex cells? Male: __testes___ Female: __ovary____
110.
What is the function of the endocrine system? Produce hormones to control body processes (usually over a
long period of time)
111.
What is a hormone? A chemical message (produce by glands) that is secreted directly into the
bloodstream
112.
How is the endocrine system different from the nervous system? (think about how messages are delivered)
The endocrine system releases chemicals into the blood, instead of traveling quickly through a nerve. The
nervous system works much faster than the endocrine system.
113.
What is the difference between an endocrine (hormone) gland and a salivary, sweat, or oil gland?
Endocrine glands deliver hormones directly into the blood, whereas the other glands do not deliver substances
into the blood.
114.
Describe what each gland controls:
a. Pituitary- secretes hormones to control growth and reproduction
b. Thyroid- secretes hormones to control your metabolism
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c. Adrenal- secretes adrenaline; located on top of the kidneys
d. Testes- male organ that produces the hormone testosterone
e. Ovaries- female organ that produces the hormones estrogen & progesterone
115. What are the 4 functions of the reproductive system?
a. Develop male/female physical characteristics
b. Produce sex cells
c. Assist in fertilization
d. Produce offspring
116. Describe the functions of the following organs of the reproductive system:
a. Penis – external male organ through which urine and semen flow out of the body
b. Scrotum – protective sac surrounding testes
c. Testes – male sex gland, produces testosterone sperm
d. Sperm – male reproductive cell, made in testes
e. Urethra – duct where semen and urine travel through
f.
Ovaries – female sex glands, produces estrogen, produce egg cells
g. Egg – female reproductive cell
h. Vagina – tube connecting uterus to outside of body
i.
Uterus – hollow organ with muscular walls, site where fertilized egg develops into an embryo
j.
Oviduct – tube that connects ovary to uterus; where fertilization occurs (a.k.a. Fallopian tube)
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