Exam
Name___________________________________
MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.
1)
Mitosis ________.
1)
A)
creates diversity in genetic potential
B)
is division of the nucleus
C)
is the formation of sex cells
D)
is always a part of the cell cycle
2)
Which of the following is not a factor that binds cells together?
2)
A)
special membrane junctions
B)
glycoproteins in the glycocalyx
C)
wavy contours of the membranes of adjacent cells
D)
glycolipids in the glycocalyx
D
3)
The electron microscope has revealed that one of the components within the cell consists of
pinwheel array of 9 triplets of microtubules arranged to form a hollow tube. This structure is a
________.
3)
A)
centrosome
B)
centriole
C)
ribosome
D)
chromosome
B
4)
Which of the following statements is correct regarding net diffusion?
4)
A)
The lower the temperature, the faster the rate.
B)
Molecular weight of a substance does not affect the rate.
C)
The greater the concentration gradient, the faster the rate.
D)
The rate is independent of temperature.
C
B
5)
Which of the following is a function of a plasma membrane protein?
5)
A)
forms a lipid bilayer
B)
circulating antibody
C)
molecular transport through the membrane
D)
oxygen transport
6)
Some hormones enter cells via ________.
6)
A)
exocytosis
B)
primary active transport
C)
receptor–mediated endocytosis
D)
pinocytosis
7)
Which of these is an inclusion, not an organelle?
7)
A)
microtubule
B)
melanin
C)
lysosome
D)
cilia
8)
Passive membrane transport processes include ________.
8)
A)
consumption of ATP
B)
movement of a substance down its concentration gradient
C)
movement of water from an area of high solute concentration to an area of low concentration
D)
the use of transport proteins when moving substances from areas of low to high concentration
9)
If a tRNA had an AGC anticodon, it could attach to a(n) ________ mRNA codon.
9)
A)
AUG
B)
UGA
C)
TCG
D)
UCG
10)
Which of the following is FALSE regarding the membrane potential?
10)
A)
The resting membrane potential occurs due to active transport of ions across the membrane
due to the sodium–potassium pump.
B)
In their resting state, all body cells exhibit a resting membrane potential.
C)
The resting membrane potential is maintained by solely by passive transport processes.
D)
The resting membrane potential is determined mainly by the concentration gradients and
differential permeability of the plasma membrane to K+ and Na+ions.
11)
What moves cell organelles from one location to another inside a cell?
11)
A)
Motor proteins
B)
Microfilaments
C)
Microtubules
D)
Intermediate filaments
12)
Crenation (shrinking) is likely to occur in blood cells immersed in ________.
12)
A)
blood plasma
B)
a hypertonic solution
C)
an isotonic solution
D)
a hypotonic solution
13)
Caveolae are closely associated with all of the following except ________.
13)
A)
enzymes involved in cell regulation
B)
lipid rafts
C)
enzymes involved in cell metabolism
D)
receptors for hormones
14)
Which type of cell junction acts as anchors and distributes tension through a cellular sheet and
reduces the chance of tearing when it is subjected to great mechanical stress?
14)
A)
tight junctions
B)
connexons
C)
gap junctions
D)
desmosomes
15)
Which structures are fingerlike projections that greatly increase the absorbing surface of cells?
15)
A)
stereocilia
B)
flagella
C)
primary cilia
D)
microvilli
16)
Which of the following statements is correct regarding RNA?
16)
A)
Messenger RNA, transfer RNA, and ribosomal RNA play a role in protein synthesis.
B)
There is exactly one specific type of mRNA for each amino acid.
C)
rRNA is always attached to the rough ER.
D)
If the base sequence of DNA is ATTGCA, the messenger RNA template will be UCCAGU.
17)
Which of the following would not be a constituent of a plasma membrane?
17)
A)
messenger RNA
B)
glycolipids
C)
glycoproteins
D)
phospholipids
18)
Once solid material is phagocytized and taken into a vacuole, which of the following statements
best describes what happens?
18)
A)
A lysosome combines with the vacuole and digests the enclosed solid material.
B)
The vacuole remains separated from the cytoplasm and the solid material persists unchanged.
C)
The phagocytized material is stored until further breakdown can occur..
D)
A ribosome enters the vacuole and uses the amino acids in the “invader” to form new protein.
19)
Which of the following is NOT a function of lysosomes?
19)
A)
degrading worn–out or nonfunctional organelles
B)
breaking down bone to release calcium ions into the blood
C)
forming acid hydrolases which are necessary to help form cell membranes
D)
digesting particles taken in by endocytosis
20)
Which of the following describes the plasma membrane?
20)
A)
a single–layered membrane that surrounds the nucleus of the cell
B)
a phospholipid bilayer surrounding the cell
C)
a membrane composed of tiny shelves or cristae
D)
a double layer of protein enclosing the plasma
21)
The functions of centrioles include ________.
21)
A)
producing ATP
B)
organizing the mitotic spindle in cell division
C)
serving as the site for ribosomal RNA synthesis
D)
providing a whiplike beating motion to move substances along cell surfaces
22)
Riboswitches are folded RNAs that act as switches to turn protein synthesis on or off in response to
________.
22)
A)
specific codes from the DNA
B)
the presence or absence of ubiquitins
C)
specific tRNAs
D)
changes in the environment
23)
The main component of the cytosol is ________.
23)
A)
sugars
B)
proteins
C)
salts
D)
water
24)
A gene can best be defined as ________.
24)
A)
noncoding segments of DNA up to 100,000 nucleotides long
B)
a segment of DNA that carries the instructions for one polypeptide chain
C)
an RNA messenger that codes for a particular polypeptide
D)
a three–base triplet that specifies a particular amino acid
25)
Which of the following is a principle of the fluid mosaic model of cell membrane structure?
25)
A)
All proteins associated with the cell membrane are contained in a fluid layer on the outside of
the cell.
B)
Phospholipids consist of a polar head and a nonpolar tail made of three fatty acid chains.
C)
The lipid bilayer is a solid at body temperature, thus protecting the cell.
D)
Phospholipids form a bilayer that is largely impermeable to water–soluble molecules.
26)
In which stage of mitosis do the identical sets of chromosomes uncoil and resume their chromatin
form?
26)
A)
telophase
B)
metaphase
C)
anaphase
D)
prophase
27)
In certain kinds of muscle cells, calcium ions are stored in ________.
27)
A)
both smooth and rough ER
B)
the cytoplasm
C)
the smooth ER
D)
the rough ER
28)
Mitochondria ________.
28)
A)
synthesize proteins for use outside the cell
B)
are single–membrane structures involved in the breakdown of ATP
C)
contain some of the DNA and RNA code necessary for their own function
D)
are always the same shape
29)
Which of the following is NOT a function of the smooth endoplasmic reticulum?
29)
A)
protein synthesis in conjunction with ribosomes
B)
breakdown of stored glycogen to form free glucose
C)
steroid–based hormone synthesis
D)
lipid metabolism and cholesterol synthesis
Explanation:
30)
Which transport process is the main mechanism for the movement of most macromolecules by
body cells?
30)
A)
pinocytosis
B)
receptor–mediated endocytosis
C)
phagocytosis
D)
secondary active transport
31)
Which of these is not a function of the plasma membrane?
31)
A)
It encloses the cell contents in such a way that water I the body is divided into separate
compartments.
B)
It acts as a site of cell–to–cell interaction and recognition.
C)
It prevents potassium ions from leaking out and sodium ions from crossing into the cell.
D)
It is selectively permeable but permits water and gases to cross.
32)
If the nucleotide or base sequence of the DNA strand used as a template for messenger RNA
synthesis is ACGTT, then what would be the sequence of bases in the corresponding mRNA?
32)
A)
ACGTT
B)
UGCAA
C)
GUACC
D)
TGCAA
33)
Which of the following statements is most correct regarding the intracellular chemical signals
known as “second messengers”?
33)
A)
Second messengers usually act to remove nitric oxide (NO) from the cell.
B)
Second messengers usually inactivate protein kinase enzymes.
C)
Second messengers act through receptors called K–proteins.
D)
Cyclic AMP and calcium may be second messengers.
34)
Peroxisomes ________.
34)
A)
are also called microbodies, and contain acid hydrolases
B)
sometimes function as secretory vesicles
C)
are able to detoxify substances by enzymatic action
D)
function to digest particles ingested by endocytosis
35)
Which of the following is NOT a role of cell adhesion molecules:
35)
A)
anchor cells to molecules in the extracellular space and to each other
B)
mechanical sensors
C)
transmitters of intracellular signals that direct cell migration, proliferation, and specialization
D)
initiators of cell–to–cell signaling for muscle contraction
36)
Which statement is the most correct regarding transcription/translation?
36)
A)
The nucleotide sequence in a mRNA codon is an exact copy of the DNA triplet that coded for
it except that uracil is substituted for thymine.
B)
The nucleotide sequence in a mRNA codon is an exact copy of the DNA triplet that coded for
it.
C)
The nucleotide sequence in a tRNA anticodon is an exact copy of the DNA triplet that coded
for it.
D)
The nucleotide sequence in a tRNA anticodon is an exact copy of the DNA triplet that coded
for it except that uracil is substituted for thymine.
37)
Which of the following does not serve as a signal for cell division?
37)
A)
loss of contact inhibition
B)
shrinking surface–to–volume ratio
C)
joining of cyclins and Cdks
D)
repressor genes
38)
If cells are placed in a hypertonic solution containing a solute to which the membrane is
impermeable, what could happen?
38)
A)
The cells will lose water and shrink.
B)
The cells will swell and ultimately burst.
C)
The cells will shrink at first, but will later reach equilibrium with the surrounding solution
and return to their original condition.
D)
The cells will show no change due to diffusion of both solute and solvent.
39)
Which vesicular transport process occurs primarily in some white blood cells and macrophages?
39)
A)
pinocytosis
B)
exocytosis
C)
intracellular vesicular trafficking
D)
phagocytosis
40)
Ribosomes, endoplasmic reticulum, and the Golgi apparatus functionally act in sequence to
synthesize and modify proteins for secretory use (export) only, never for use by the cell. This
statement is ________.
40)
A)
true
B)
false; proteins thus manufactured are for use inside the cell only
C)
false; integral cell membrane proteins are also synthesized this way
D)
false; lipids, not proteins, are synthesized this way
41)
The RNA responsible for bringing the amino acids to the ribosome for protein formation is
________.
41)
A)
ssRNA
B)
mRNA
C)
rRNA
D)
tRNA
42)
A red blood cell placed in pure water would ________.
42)
A)
swell and burst
B)
shrink
C)
neither shrink nor swell
D)
swell initially, then shrink as equilibrium is reached
SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question.
43)
Explain the term genetic code. What does it code for? What are the letters of the code?
43)
44)
The process of discharging particles from inside a cell to the outside is called ________.
44)
Figure 3.1
Using Figure 3.1, match the following:
45)
Source of cell autolysis.
45)
Figure 3.2
Using Figure 3.2, match the following:
46)
Polar region of phospholipid.
46)
47)
List possible causes of aging.
47)
Figure 3.1
Using Figure 3.1, match the following:
48)
Site of enzymatic breakdown of phagocytized material.
48)
49)
Water may move through membrane pores constructed by transmembrane proteins called
________.
49)
50)
In all living cells hydrostatic and osmotic pressures exist. Define these pressures and
explain how they are used in the concept of tonicity of the cell.
50)
Figure 3.2
Using Figure 3.2, match the following:
51)
Nonpolar region of phospholipid.
51)
52)
Peripheral protein.
52)
Figure 3.1
Using Figure 3.1, match the following:
53)
Replicate for cell division.
53)
54)
A red blood cell would swell if its surrounding solution were ________.
54)
55)
Describe two important functions of the Golgi apparatus.
55)
56)
What major chemical is responsible for apoptosis?
56)
57)
________ is the division of the cytoplasmic mass into two parts.
57)
58)
Why can we say that a cell without a nucleus will ultimately die?
58)
Figure 3.2
Using Figure 3.2, match the following:
59)
Identification “tags” for the cell.
59)
60)
What processes maintain a steady state “resting” membrane potential?
60)
Figure 3.2
Using Figure 3.2, match the following:
61)
Hydrophilic portion of phospholipid.
61)
62)
In order for the DNA molecule to get “short and fat” to become a chromosome, it must first
wrap around small molecules called ________.
62)
63)
Other than the nucleus, which organelle has its own DNA?
63)