Answers to End-of-Chapter Questions – Brooker et al ARIS site
Chapter 4
Test Yourself Questions
1. The cell doctrine states that
a. any living organism is composed of one or more cells.
b. new cells are derived from organic molecules from the environment.
c. the smallest units of living organisms are atoms.
d. the function of cells depends on the shape of the cell.
e. all of the above.
Answer: a. The cell doctrine states that all living things are composed of cells, new cells are derived
from pre-existing cells by cell division and that the smallest unit of life is a cell.
2. When using microscopes, the resolution refers to
a. the ratio between the size of the image produced by the microscope and the actual size of
the object.
b. the degree to which a particular structure looks different from other structures around it.
c. how well a structure takes up certain dyes.
d. clarity of an image.
e. the degree to which the image is magnified.
Answer: d. Resolution is a measure of the clarity of an image.
3. A bacterial cell may possess a ___________, which may protect it from the immune system of other
multicellular organisms that it may infect.
a. cell wall
b. flagellum
c. pili
d. nucleoid
e. capsule
Answer: e. Bacterial cells with a capsule may have a lower probability of being destroyed by the immune
system of organisms that they infect.
4. Different cells of the same multicellular individual have different proteomes due to all of the following
except
a. differences in the types of proteins made in different cell types.
b. differences in the genomes of the different cell types.
c. the abundance of certain proteins may not be the same in different cell types.
d. the amino acid sequences of proteins may be different in different cell types.
e. different cell types may alter the proteins in different ways.
Answer: b. All nucleated cells of the same organism have essentially identical genomes. The differences
in proteomes are usually the result of differences in gene expression levels and modifications during
and after protein synthesis.
5. The process of polypeptide synthesis is called
a. metabolism.
b. transcription.
c. translation.
d. hydrolysis.
e. both c and d.
Answer: c. Translation is the process of polypeptide synthesis, the chemical reactions involved in linking
amino acids together.
6. Each of the following is part of the endomembrane system except
a. the nuclear envelope.
b. the endoplasmic reticulum.
c. the Golgi apparatus.
d. lysosomes.
e. peroxisomes.
Answer: e. Peroxisomes are not considered part of the endomembrane system.
7. Molecules move into and out of the nucleus by
a. diffusing through the nuclear membrane.
b. transport proteins.
c. moving through nuclear pores.
d. attaching to the nucleolus.
e. all of the above.
Answer: c. Nuclear pores provide passageways into and out of the nucleus.
8. Functions of the smooth endoplasmic reticulum include
a. detoxification of harmful organic molecules.
b. metabolism of carbohydrates.
c. protein sorting.
d. all of the above.
e. a and b only.
Answer: e. Though protein sorting does initiate in the rough endoplasmic reticulum, the smooth
endoplasmic reticulum functions in other metabolic processes including carbohydrate and lipid
metabolism, storage and detoxification.
9. The central vacuole in many plant cells is important for
a. storage.
b. photosynthesis.
c. structural support.
d. all of the above.
e. a and c only.
Answer: e. The central vacuole serves as a storage site but also provides structural support to the cell.
10. Peroxisomes
a. are vesicles similar to lysosomes that break down different classes of macromolecules.
b. play an important role in the synthesis of ATP.
c. are vesicles that contain enzymes necessary for manufacturing complex sugars.
d. are the organelles primarily involved in protein synthesis.
e. contain the enzyme catalase that breaks down hydrogen peroxide to water and oxygen.
Answer: e. Peroxisomes contain catalase, an enzyme that breaks down hydrogen peroxide producing
water and oxygen.