Chapter 7 Review Sheet
1.
NAME
What are the 3 key points of what is known as the cell theory.
*cells are the smallest unit of structure and function
*cells come only from existing cells
*all living things are composed of one or more cells
2.
In a previous chapter, we learned that a cell could be thought of as a solution. Explain why.
Cells are filled with a fluid-like substance called cytoplasm. Floating in it are many organelles, as well
as ions and organic molecules. The cytoplasm can be thought of as a solvent, and the substances floating in it
are like solutes.
3.
What is the main way we could distinguish between a prokaryotic cell and a eukaryotic cell?
Look for the presence a nucleus. Eukaryotes (“true nucleus”) have a membrane-bound nucleus that
separates the genetic material from the rest of the cell. Prokaryotes (“before nucleus”) do not; the area in the
cytoplasm where their genetic material is located is referred to as the nucleoid, because it is not separated
from the other contents of the cytoplasm.
4.
What is the main way we could distinguish between a plant and animal cell?
The presence of a cell wall and chloroplasts. Animal cells do not have a cell wall, nor do they have
chloroplasts.
5.
Name a type of organism that is a prokaryote. Bacteria
6.
Fill in the table below:
ORGANELLE
Nucleus
LOCATION
cytoplasm
Nucleolus
nucleus
Golgi Apparatus
cytoplasm
Lysosome
cytoplasm
Mitochondrion
cytoplasm
Rough Endoplasmic Reticulum
cytoplasm
Cell Membrane
cytoplasm
Cytoskeleton
cytoplasm
FUNCTION
Separates the genetic material
from the rest of the contents of
the cell
the specific location of the
genetic material; the primary
controller of all cell function
Processing or packaging of
proteins and lipids for
transport out of the cell
Breaks down and recycles
macromolecules
Converts chemical energy from
food to the energy currency of
the cell (ATP)
Protein synthesis—the
assembly of proteins (Smooth
ER is responsible for the
assembly of lipids)
Selective transport of materials
in and out of the cell
Support and protection of the
cell
Cell Wall
Surrounds cell membranes in
plants and some bacteria
Support and protection of the
cell
Ribosomes
cytoplasm
Protein synthesis
Cytoplasm
Everywhere inside the cell
membrane but outside of the
nucleus
Chloroplast
cytoplasm
Gives the cell shape and allows
movement of molecules and
organelles from one part of the
cell to another
Photosynthesis—harvests
energy from the sun
Vacuole
cytoplasm
storage
Microtubule/Microfilament
cytoplasm
Support and protection of the
cell
Vesicle
cytoplasm
storage
7.
Differentiate between diffusion and osmosis.
Diffusion is the movement of molecules from an area of high concentration to an area of low
concentration. Osmosis refers specifically to the diffusion of WATER across a selectively permeable
membrane
8.
What intramembrane structures are involved in facilitated diffusion and active transport?
proteins
9.
each.
What are the 3 main kinds of microscopes used by biologists? Describe the type of image produced by
Compound light microscopes are used most often because they are small and easy to work with in the
lab. They bend light rays with a series of lenses, and produce a 2-dimensional image that magnifies hundreds
of times (maybe 1000 or so on some models). The transmission electron microscope also produces a 2-D
image but it may be magnified hundreds of thousands of times. These are large microscopes, usually, and
require at least a small room JUST for the microscope (although they are coming out with smaller models,
these are very expensive). The scanning electron microscope produces a 3-D image of an object, and
magnifies the object thousands of times
10.
Consider the levels of organization of living things, as discussed in class (cellorganism). List them in
hierarchical order, and give an example of each.
Cell (cheek cell)tissue (muscle)organ (heart)organ system (circulatory system)organism (human)
11.
What does the term “selectively permeable” mean? Why don’t we just say “permeable,” and save some
breath?
A permeable barrier will let many substances through. Water is a barrier to the bottom of the lake,
but it will let just about anything through. A selectively permeable membrane will only let some things
through, like one of the “net” bags onions are stored in at the grocery store. Small items will fall right through
the bag, but larger ones will not.
12.
How are endocytosis and exocytosis similar? How are they different?
They are both processes that move things in or out of the cell using large portions of the cell
membrane. Endocytosis brings a substance into the cell; exocytosis sends them outside of the cell.
13.
Why don’t animal cells have cell walls?
Cell walls are very rigid. If animals had cell walls, they would not be flexible and their movements
would be hindered.
14.
Differentiate between the following terms, and state what would happen to a “normal” cell in each
environment:
Isotonic: has a solute concentration that is equal to that of a cell (a typical cell has a concentration of 0.9 %
sodium chloride, for example…an isotonic solution would also be 0.9 %). Movement of water molecules both
into and out of the cell would be equal [equilibrium] so there is no net gain or loss of water. The cell remains
the same size.
Hypotonic: has a solute concentration LOWER than that of a cell; this means the water concentration is
greater OUTside of the cell, so water will move INTO the cell until equilibrium is reached, or the cell bursts,
whichever comes first. Any sodium chloride concentration less than 0.9% is hypotonic.
Hypertonic: has a solute concentration GREATER than that of a cell; this means the water concentration is
greater INside of the cell, so water will move OUT of the cell, so the cell shrinks (plasmolysis) Any sodium
chloride concentration MORE than 0.9% is hypertonic.
15.
What is the difference between smooth and rough endoplasmic reticulum? Do they have different
functions? Rough endoplasmic reticulum has ribosomes associated with it, and it functions in the synthesis of
proteins. Smooth ER does not have ribosomes, and functions in lipid synthesis
16. The following cell is a(n)__________prokaryote_______________. Label the indicated parts.
1. cell membrane
2. cell wall or capsule
3. cytoplasm
4. genetic material
5. ribosomes
6. pili
7. flagella
17.
Label the parts indicated:
c
Left column: cell wall, cell membrane, central vacuole, nucleus, nucleolus, nuclear membrane,
chloroplast, mitochondria
Right column: cytoplasm, rough endoplasmic reticulum, smooth endoplasmic reticulum, ribosomes,
Golgi apparatus
18.
In the third type of cell, what structures would be different than (present or absent) from the cell
above? The third cell type would be an animal cell, It would not have a cell wall, chloroplasts or a large
central vacuole. It would also have more mitochondria