Study Guide Answers
Page 48 • Section 7.2
1. balance
2. homeostasis
3. glucose
4. plasma membrane
5. selective permeability
6. organism
7. false
8. true
9. false
10. false
11. true
12. true
13. false
Page 49 • Section 7.3
1. vacuole
2. Golgi apparatus
3. ribosomes
4. endoplasmic reticulum
5. cytoplasm
6. nucleus
7. chloroplast
8. lysosomes
9. ribosomes
10. vacuole
11. cell wall
12. mitochondria or chloroplast
13. Golgi apparatus
14. chloroplast
15. plastids
16. true
17. cytoskeleton
18. true
19. locomotion
20. Cilia
21. less
22. unicellular
23. eukaryotic
24. animal cell
25. plant cell
26. plasma membrane
27. lysosome
28. cell wall
29. chloroplast
30. large vacuole
Concept Mapping
Page 55 • Recycling in the Cell
1. Lysosomes
2. vacuoles
3. tail
4. digestive enzymes
5. cell proteins
6. digestive enzymes
7. digesting it
8. a membrane
9. worn-out cell parts
10. food particles
11. bacteria and viruses
Page 56 • Cell Organelles and Their Functions
1. a. Mitochondria break down and release stored
energy for the cell.
b. In most people, the activity of muscles and nerve
tissues decreases with age and the decrease may
be because fewer mitochondria are releasing
energy to sustain activity. The DNA difference may
be the cause of fewer properly functioning
mitochondria in older people.
2. The decrease in activity of heart muscle with age
may be caused by defective DNA.
3. All three symptoms involve disorders of muscle
tissues, which depend on mitochondria releasing
energy to function properly.
4. Lysosomes; lysosomes contain digestive
enzymes, which are used to digest worn-out cell
parts and viruses among other things.
5. Constant doses of alcohol must have caused the
liver to produce more smooth endoplasmic
reticulum for detoxification.
Reinforcement and Study Guide
Page 47 • Section 7.1
1. f
2. b
3. e
4. a
5. d
6. c
7. prokaryotes
8. prokaryotes
9. eukaryotes
10. prokaryotes
11. eukaryotes
Page 57
• Answers to questions on the transparency
include:
1. The image produced by the light microscope
shows the entire organism, but does not show
much detail. The image produced by the TEM
shows greater magnification and therefore greater
detail.
The SEM shows the paramecium in a threedimensional image, but only the surface is visible.
2. Answers might include: The light microscope
could be used to view entire organisms that are too
large to be seen by the TEM. The TEM would be a
good choice to view the details of cell parts. The
SEM shows the surface of the specimen in a threedimensional image
Page 58
1. The sugar is passing through the membrane; the
starch is not.
2. The membrane controls what materials move
through it.
Page 59
1. Plants and animals need food and water to stay
alive. Plants also need sunlight.
Animals (especially humans) need some sunlight
as well.
2. Responses could include: Plant and animals
cells will each have a nucleus, plasma membrane,
ribosomes, cytoskeleton, Golgi apparatus,
endoplasmic reticulum, lysosomes, mitochondria,
and vacuoles. In addition, plants contain
chloroplasts to make food in photosynthesis.
Page 62
Answers to Student Worksheet
1. The phospholipid in the transparency is a
molecule consisting of a phosphate group and two
fatty acid chains linked to glycerol.
2. The phosphate, or polar end, is attracted to
water.
3. There are two layers of phospholipids in the
plasma membrane, arranged with the phosphate
ends facing the outside of each layer and the fatty
acid ends facing the inside.
4. Many proteins regulate the permeability of the
membrane to various substances, some function as
enzymes, and others serve as markers that enable
the immune system to distinguish an organism’s
own cells from foreign cells.
5. The model shows phospholipid molecules that
are not chemically bonded to one another but,
rather, are free to move sideways through their
layer, allowing the membrane to behave like a fluid.
6. It would be very fluid.
7. The cholesterol molecules help stabilize the
phospholipids.
Page 64
1. Endoplasmic reticulum, Golgi apparatus,
ribosome, vacuole, cytoskeleton, lysosome, plasma
membrane, mitochondria, nucleus, and nucleolus
2. lysosome
3. chloroplast
4. The central vacuole is s storage organelle.
5. A cell containing many chloroplasts would carry
on a lot of photosynthesis to make food for the
plant.
6. Some plant cells do not photosynthesize.
Examples of cells that do not engage in
photosynthesis are the interior cells of stems and
most root cells.
7. ribosomes
8. Mitochondria release energy necessary for
movement.
Page 66
1. The diaphragm is used to regulate the amount of
light that passes through the specimen.
2. To change the objective lens, you must rotate
the revolving nosepiece.
3. The coarse adjustment knob is turned to focus
the image under low power.
4. A light source transmits light through the
diaphragm, specimen, and lenses, allowing you to
view the specimen.
5. The term compound refers to the fact that
modern light microscopes consist of two sets of
lenses, one in the eyepiece and the other in the
objective.
6. The specimen slide is positioned on the stage of
the microscope and held in place by the stage
clips.
7. The total magnification is 10 3 45 5 4503.
8. Van Leeuwenhoek’s microscope had only a
single
magnifying lens, whereas compound microscopes
have a series of lenses, thereby allowing for
greater magnification.
9. A compound light microscope can magnify
objects only to about 1500 times their actual size
because of the limitations imposed by light waves.
TEMs use electrons, rather than light. They can
magnify objects hundreds of thousands of times
and produce images that are two-dimensional.
However, because the specimen must be viewed in
a vacuum, only dead cells or organisms can be
viewed.
Page 68
1. manages cell functions; includes chromatin and
the nucleolus, which produces ribosomes; involved
in protein synthesis
2. boundary between the cell and its external
environment; allows cell to vary shape as needed;
controls the movement of materials that enter and
exit the cell
3. provides a large surface area on which chemical
reactions can take place; site for lipid synthesis; is
cell’s delivery system, providing materials for
ribosomes as they synthesize proteins
4. breaks down food molecules to release energy,
which is then stored in other molecules that can
power cell reactions easily
5. receives newly synthesized proteins and lipids
from the ER and distributes them to the plasma
membrane and other cell organelles; chemically
modifies proteins, then repackages them for
distribution to final destination
6. provides support for organelles; also helps
maintain cell shape; includes microtubules and
microfilaments
Page 69 • Reviewing Vocabulary
1. cell wall
2. nucleus
3. chromatin
4. endoplasmic reticulum
5. chlorophyll
6. cytoskeleton
7. chloroplasts
8. Transport proteins
9. cilia
10. mitochondria
11. prokaryote
12. plasma membrane
13. organelles
14. ribosomes
15. lysosomes
Page 70 • Understanding Concepts (Part A)
1. a
6. b
2. d
7. a
3. b
8. a
4. d
9. c
5. b
10. c
Page 71 • Understanding Concepts (Part B)
1. A is the ribosomes; B is the DNA; C is the
plasma membrane; D is the cell wall.
2. Scientists would classify this bacterium as a
prokaryote because it has no membrane-bound
internal structures and it does not have a distinct
nucleus, even though it does contain DNA.
3. Mitochondria are organelles that produce energy
for cell reactions; active cells usually have more
mitochondria than do less active cells. It would be
reasonable to conclude that the number of
mitochondria is in direct relation to the amount of
work done by the cells.
4. Cells could not be studied in detail until the
technology was available to develop efficient
microscopes.