Download Chapter 7 Cell Structure and Function ANSWER KEY

Chapter 7 Cell Structure and Function
Section Review 7-1
1. living things 2. structure; function 3. existing
cells 4. nucleus; prokaryotes 5. organelles
6. prokaryotic cell 7. eukaryotic cell 8. The giant
amoeba is 5000 times larger than the smallest bacterium. 9. Prokaryotic and eukaryotic cells carry out
the functions required for living, and both contain
cytoplasm as well as cell membranes. Eukaryotic
cells contain organelles and have a nucleus, whereas
prokaryotic cells do not. 10. Eukaryotic; the cells of
all multicellular living things, including humans, are
eukaryotic.
Section Review 7-2
1. b 2. g 3. a 4. c 5. f 6. d 7. e 8. Chloroplasts
store energy in food molecules. Mitochondria release
the energy stored in food molecules. Plants need
chloroplasts and mitochondria because they require
both functions. 9. Possible student answer: One
function of lysosomes is to remove debris that might
clutter a cell. This is analogous to the work a cleanup
crew in a factory might perform. 10. A plant cell has
cell walls and chloroplasts, structures not found in
animal cells. An animal cell has the unique structures
of lysosomes.
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Section Review 7-3
ANSWER KEY
most of the dribbling and another player to do most
of the rebounding. 9. The tongue can move and
taste, so it must have muscle and nervous tissue. A
group of different tissues, like a tongue, is called an
organ. 10. Tissues and organs are different levels of
organizations in a multicellular organism. A tissue is
a group of similar cells that performs a particular
function, whereas an organ consists of groups of tissues that work together.
Chapter Vocabulary Review
1. c 2. i 3. f 4. h 5. j 6. e 7. a 8. d 9. b 10. g
11. a 12. c 13. d 14. b 15. c 16. ribosome
17. rough endoplasmic reticulum 18. Golgi apparatus 19. Mitochondrion 20. chromosomes 21. diffusion 22. selective permeability 23. osmosis 24.
facili-tated diffusion 25. active transport
Enrichment
1. Morphogenesis is the process of cell differentiation,
while histogenesis is the development of tissues.
These processes are similar because they both involve
changes during embryological development and both
are required for the development of a multicellular
organism. 2. The instructions for the process of histogenesis are stored in the chromosomes.
1. The cell membrane regulates what enters and
Graphic Organizer
leaves the cells and provides protection and support
for the cell. 2. The dissolved molecules will slowly
diffuse to the lower concentration side until an equilibrium is established. 3. Osmosis is the diffusion of
water through a selectively permeable membrane.
4. facilitated diffusion 5. active transport 6. hypertonic solution; Water will move out of the cell, causing it to shrink. 7. isotonic solution; There is
equilibrium. Water will move both in and out of the
cell, and the cell will not change shape. 8. hypotonic
solution; Water will move into the cell, causing it to
swell.
1. Plant cells 2. Chloroplasts 3. Cell wall
4. Mitochondria 5. Ribosomes 6. Genetic
Section Review 7-4
1. Multicellular organisms contain specialized cells
so that certain cells can perform particular functions
in the organism. 2. Possible student answers
include: Nerve cells: transmit information;
Pancreatic cells: produce protein enzymes and
compounds such as insulin; Red blood cells: transport oxygen; Muscle cells: contract and relax to
move body parts. 3. 2 4. 4 5. 3 6. 1 7. A specialized cell performs a single life function. A unicellular organism performs all of its necessary life
functions. 8. Possible student answer: The specialized cells of a multicellular organism are analogous
to players on a basketball team who possess different skills. The team depends on one player to do
Teaching Resources /Chapter 7
information/DNA
Exploration
Analyze and Conclude 1. Onion cells are generally rectangular, with some variation in size and
shape. Cheek cells are flat and roughly circular. The
onion cells have rigid cell walls and distinct nuclei,
both of which stain with iodine. Students may be
able to see vacuoles in the centers of onion cells and
dark spots (other organelles) outside the nucleus. The
cheek cells do not have cell walls. Students should be
able to see cell membranes as well as the nucleus
within each cell. They may also see other dark spots
(other organelles). Cell walls protect the cell and provide support. The nucleus directs cell activities and is
where genetic material is stored. Vacuoles store water
and other materials. Cell membranes regulate what
enters and leaves the cell. 2. Plant and animal cells
both have cell membranes and nuclei. Plant cells
have cell walls, whereas animal cells do not. 3. The
concentration of water was greater inside the cells
than in the salt solution, so osmotic pressure
moved water out of the cells. The cytoplasm of the
cells then shrank away from the cell walls. 4. In
step 13, the cells shrank. Because the concentration of
water was greater inside the cells than in the salt
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solution outside the cells, water diffused out of the
cells. In step 15, the cells expanded, and some may
have burst. Because the concentration of water was
greater in the distilled water than inside the cells,
water diffused into the cells. 5. The cell membrane
was involved. Water moves in and out of the cell by
osmosis through the cell membrane. 6. The cell
walls of the onion cells are strong enough to keep the
cells from bursting. Animal cells do not have cell
walls, so they may burst.
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Teaching Resources /Chapter 7