Chapter 01: Cellular Biology
Test Bank
TRUE/FALSE
1. Eukaryotic cells are characterized by a lack of a distinct nucleus, whereas prokaryotic
cells have intracellular compartments bordered by membranes and a well-defined nu-
cleus.
ANS: F
Eukaryotic cells have a characteristic set of membrane-bound intracellular compartments
called organelles that includes a well-defined nucleus. Prokaryotes contain no organelles,
and their nuclear material is not encased by a nuclear membrane. Prokaryotic cells are chara-
cterized by lack of a distinct nucleus.
REF: p. 2
2. The primary functions of the cell nucleus are cell division and control of genetic infor-
mation.
ANS: T
The primary functions of the nucleus are cell division and control of genetic information.
REF: p. 2
3. The chief function of ribosomes is to provide sites for lipid synthesis.
ANS: F
Their chief function is to provide sites for cellular protein synthesis.
REF: p. 5
4. Lysosomes remain fully active by maintaining an acid pH created by pumping hydrogen
ions into their interiors.
ANS: T
Lysosomes remain fully active by maintaining a low internal pH. They do this by pumping
hydrogen ions into their interiors.
REF: p. 5
5. Lipids and proteins are the major components of the plasma membrane.
ANS: T
The major chemical components of all membranes are lipids and proteins, but the percentage
,of each varies among different membranes.
REF: p. 11
6. If cells are deprived of communication from extracellular chemical messengers, most
cells experience apoptosis.
ANS: T
If deprived of appropriate signals, most cells undergo a form of cell suicide known as pro-
grammed cell death, or apoptosis.
REF: p. 19
7. The function of adenosine triphosphate (ATP) is to store energy in molecules of car-
bohydrates, proteins and lipids, but not to transfer energy from one molecule to another.
ANS: F
The function of ATP is not only to store energy but also to transfer it from one molecule to
another.
REF: p. 23
8. Diffusion is an example of active transport.
ANS: F
This process, called passive transport, occurs naturally through any semipermeable barrier.
It is driven by osmosis, hydrostatic pressure, and diffusion, all of which depend on the laws
of physics and do not require life.
REF: p. 25
9. Phagocytosis is an example of exocytosis.
ANS: F
Two types of endocytosis are designated based on the size of the vesicle formed.
Pinocytosis (cell drinking) involves the ingestion of fluids and solute molecules through
formation of small vesicles, and phagocytosis (cell eating) involves the ingestion of large
particles, such as bacteria, through formation of large vesicles (also called vacuoles).
REF: p. 31
10. All body cells are electrically polarized, with the inside of the cell being more negatively
charged than the outside.
ANS: T
All body cells are electrically polarized, with the inside of the cell more negatively charged
than the outside.
,REF: p. 32
MULTIPLE CHOICE
1. Which of the following best describes the cellular function of metabolic absorption?
a Cells can produce proteins.
.
b Cells can secrete digestive enzymes.
.
c Cells can take in and use nutrients.
.
d Cells can synthesize fats.
.
ANS: C
In metabolic absorption all cells take in and use nutrients and other substances from their
surroundings.
REF: p. 2
2. Most of a cell’s genetic information, including RNA and DNA, is contained in the:
a mitochondria.
.
b ribosome.
.
c nucleolus.
.
d lysosome
.
ANS: C
The nucleus contains the nucleolus, a small dense structure composed largely of RNA; most
of the cellular DNA; and the DNA-binding proteins, the histones, that regulate its activity.
REF: p. 2
3. Which component of the cell produces hydrogen peroxide (H2O2) by using oxygen to
remove hydrogen atoms from specific substrates in an oxidative reaction?
a Lysosomes
.
b Peroxisome
.
c Ribosomes
.
d Oxyhydrosomes
.
, ANS: B
Peroxisomes are so named because they usually contain enzymes that use oxygen to remove
hydrogen atoms from specific substrates in an oxidative reaction that produces H2O2. Hyd-
rogen peroxide is a powerful oxidant and potentially destructive if it accumulates or escapes
from peroxisomes.
REF: p. 7
4. Which cell component is capable of cellular autodigestion when it is released during cell
injury?
a Ribosome
.
b Golgi complex
.
c Smooth endoplasmic reticulum
.
d Lysosomes
.
ANS: D
The lysosomal membrane acts as a protective shield between the powerful digestive enzymes
within the lysosome and the cytoplasm, preventing their leakage into the cytoplasmic matrix.
Disruption of the membrane by various treatments or cellular injury leads to a release of the
lysosomal enzymes, which can then react with their specific substrates, causing cellular
self-digestion.
REF: p. 5
5. What is the sequence of steps in the development of a digestive enzyme by the pancreas
cells from the initial transcription to the release from the cell?
a The enzyme is transcribed from DNA by RNA in the nucleus, proceeds to the
. ribosome for synthesis, and is transported in a secretory vesicle to the cell
membrane.
b The enzyme is transcribed from RNA by DNA in the nucleus, proceeds to the
. lysosome for synthesis, and is transported in an encapsulated membrane to the
cell membrane.
c The enzyme is transcribed by the mitochondria in the nucleus, proceeds to the
. ribosome for synthesis, and is transported in a cytoskeleton to the cell membrane.
d The enzyme is transcribed from DNA by RNA in the nucleus, proceeds to the
. Golgi complex for synthesis, and is transported in a cytosol to the cell membrane.
ANS: A
The enzyme is transcribed from DNA by RNA in the nucleus, proceeds to the ribosome for
synthesis, and is transported in a secretory vesicle to the cell membrane.
REF: pp. 6-8; Figure 1-5