Chapter 3 Flashcards
1
Q
Histones are found in
1. proteasomes. 2. lysosomes. 3. vesicles. 4. endosomes. 5. nucleosomes.
A
- nucleosomes
2
Q
Most of a cell’s DNA is located in its
1. Golgi apparatus. 2. lysosomes. 3. ribosomes. 4. nucleolus. 5. nucleus.
A
- nucleus
3
Q
The functional units of DNA that contain the instructions for making one or more proteins are ribosomes. RNA. chromosomes. codons. genes.
A
genes
4
Q
The nucleus is surrounded by the ________.
A
nuclear envelope
5
Q
DNA \_\_\_\_\_.
contains uracil
is processed to remove introns
is non-complementary
is transcribed into RNA
A
is transcribed into RNA
6
Q
The set of three nucleotides on the mRNA strand that are read by the ribosome is termed the \_\_\_\_\_\_\_. "codon" "tRNA" "anti-codon" "triplet"
A
codon
7
Q
Which enzyme transcribes DNA? DNA transcriptase RNA polymerase DNA polymerase RNA reductase
A
RNA polymerase
8
Q
Transcription directly results in the formation of \_\_\_\_\_\_\_\_\_\_. DNA messenger RNA histones All of these
A
messenger RNA
9
Q
A mature red blood cell lacks a nucleus; therefore, it
1. is malformed. 2. can only divide once more. 3. can repair itself readily. 4. cannot make new proteins and will be worn out within a few months. 5. will be a long-lived cell.
A
- cannot make new proteins and will be worn out within a few months.
10
Q
The process of protein formation directed by mRNA is called replication. auscultation. translation. transcription. mitosis.
A
translation
11
Q
The anticodon for the triplet UCA is AGC. AGT. TGT. AGU. TCA.
A
AGU
12
Q
Before the mRNA transcribed from a gene can be used to translate into a protein, it must be
1. edited to remove introns and transported into the cytoplasm. 2. coated with phospholipids for transport out of the nucleus. 3. edited to remove introns. 4. transported into the cytoplasm. 5. edited to remove exons.
A
- edited to remove introns and transported into the cytoplasm.
13
Q
The molecule that brings the proper amino acid into place at the ribosome for the elongation of a new protein is called ATP. mRNA. Na-K. tRNA. rRNA.
A
tRNA
14
Q
Thymine is replaced by which nitrogen base in RNA? guanine thymine is not replaced in RNA uracil cytosine ribose
A
uracil
15
Q
The duplication of DNA is called ________, the copying of DNA to mRNA is called ________, and the reading of the mRNA by the cell to make a protein is called ________ .
1. reproduction, duplication, initiation
2. replication, transcription, translation
3. mitosis, duplication, protein synthesis
4. replication, translation, transcription
5. interphase, replication, active transport
A
- replication, transcription, translation
16
Q
Ribosomes are composed of protein and ________.
A
RNA
17
Q
The enzyme ________ is required for the synthesis of mRNA.
A
RNA polymerase
18
Q
The start of each gene begins with a ________ segment.
A
promoter
19
Q
Permanent alterations in a cell’s DNA that affect the nucleotide sequence of one or more genes are called ________.
A
mutations
20
Q
Which of the following best explains diffusion?
- movement of molecules from where there are fewer of them to where there are more
- movement of molecules farther away from equilibrium
- movement of molecules from an area of high concentration to an area of low concentration
- exchange of nonpolar molecules for polar molecules
A
- movement of molecules from an area of high concentration to an area of low concentration
21
Q
Which of the following is most likely to move through the cell membrane by facilitated diffusion? CO2 Na+ O2 small lipids
A
Na+
22
Q
What is the basic difference between simple diffusion and facilitated diffusion across a cell membrane?
1. In simple diffusion, molecules move down the concentration gradient but in facilitated diffusion molecules move up the concentration gradient. 2. In facilitated diffusion, molecules only move with the aid of a protein in the membrane. 3. Simple diffusion requires molecules to move through special doorways in the cell membrane. 4. Simple diffusion is passive but facilitated diffusion is an active process that uses energy.
A
- In facilitated diffusion, molecules only move with the aid of a protein in the membrane.
23
Q
Which of the following is least likely to increase the rate of diffusion? small molecule size small concentration gradient higher concentration of molecules high temperature
A
small concentration gradient
24
Q
Which of the following is not required for osmosis to occur? water concentration gradient energy selectively permeable membrane
A
energy
25
```
Which of the following solutions contains the most solute?
hypotonic
hypertonic
equilibrium
isotonic
```
hypertonic
26
In general, to maintain homeostasis the relationship between our intracellular and extracellular fluids should be which of the following?
1. intracellular and extracellular should both be hypertonic
2. intracellular should be hypotonic to extracellular
3. intracellular should be hypertonic to extracellular
4. isotonic to each other
isotonic to each other
27
If a person is severely dehydrated, their extracellular fluids will become hypertonic to the intracellular fluid. What do you predict will happen to the person’s cells?
1. The cells will swell.
2. The cells will lose water and shrink.
3. Extracellular fluids do not impact cell size, because cells contain intracellular fluid.
4. The cells will rupture.
2. The cells will lose water and shrink.
28
A primary active transport process is one in which __________.
a. molecules move through transport proteins that have been activated by ATP
b. the plasma membrane folds inward to form a vesicle containing extracellular material
c. molecules move across the plasma membrane without an input of energy
d. molecules pass directly through the phospholipid bilayer of the plasma membrane
e. an intracellular vesicle fuses with the plasma membrane and releases its contents to the extracellular fluid
a. molecules move through transport proteins that have been activated by ATP
29
```
Some transport processes use transport proteins in the plasma membrane, but do not require ATP. This type of transport is known as _____.
exocytosis
simple diffusion
facilitated diffusion
active transport
endocytosis
```
facilitated diffusion
30
The majority of water molecules moving across plasma membranes by osmosis do so via a process that is most similar to ____.
active transport
simple diffusion
facilitated diffusion
a process that requires energy from the cell
cotransport
facilitated diffusion
31
```
The sodium-potassium pump uses ATP to move sodium and potassium ions across the plasma membrane. This statement describes _____.
facilitated diffusion
simple diffusion
primary active transport
secondary active transport
exocytosis
```
primary active transport
32
```
A vesicle fuses with the plasma membrane and releases its contents to the extracellular fluid. This statement describes _____.
simple diffusion
active transport
endocytosis
facilitated diffusion
exocytosis
```
exocytosis
33
Of the three major fluid compartments in the body, what is the fluid that surrounds the cells called?
intracellular fluid
interstitial fluid
plasma
interstitial fluid
34
```
Which of the following is the major extracellular cation?
calcium
sodium
potassium
magnesium
```
sodium
35
```
Phosphates are abundant in the intracellular fluid. What is the other major intracellular anion?
proteins
potassium
chloride
bicarbonate
```
proteins
36
The Na+-K+ ATPase pump is important for secondary active transport of other solutes. How does this pump work to bring in other solutes?
1. K+ is pumped out of the cell, creating a lower K+ concentration inside the cell.
2. Na+ is pumped into the cell, creating a lower concentration of Na+ outside the cell.
3. Na+ is pumped out of the cell, creating a lower Na+ concentration inside the cell.
3. Na+ is pumped out of the cell, creating a lower Na+ concentration inside the cell.
37
If more solute particles are added to the right side of a beaker with a selectively permeable membrane (thus the particles cannot move to the left side), which way will the water in the beaker move, and why will it move in that direction?
a. Water will move to the right side of the beaker because the right side is hypertonic compared to the left side.
b. Water will move to the left side of the beaker because the left side is hypotonic compared to the right side.
c. Water will move to the right side of the beaker because it is hypotonic compared to the left side.
a. Water will move to the right side of the beaker because the right side is hypertonic
38
What happens to a patient’s red blood cells when a hypotonic solution is given?
The red blood cells will crenate.
The red blood cells would expand and eventually hemolysis would result.
The red blood cells would stay the same size.
The red blood cells would expand and eventually hemolysis would result.
39
```
Diffusion of a substance across the cell membrane is influenced by all of the following, except
hydrolysis of ATP.
the charge on the ion.
lipid solubility.
the presence of the membrane channels.
concentration gradient.
```
hydrolysis of ATP.
40
Water molecules and small ions enter a cell through
peripheral carbohydrates.
defects in the lipid layer of the membrane.
channels formed by integral proteins.
lipid channels.
peripheral proteins.
channels formed by integral proteins.
41
```
A solution that contains a lower osmotic pressure than the cytoplasm of a cell is called
hypertonic.
homotonic.
merotonic.
hypotonic.
isotonic.
```
hypotonic
42
Which statement best describes osmosis?
1. active transport of water across the cell membrane
2. random movement of water due to kinetic energy
3. diffusion of water from a greater to a lesser water concentration
4. diffusion of water from a greater to a lesser water concentration across a selectively permeable membrane
5. movement of water into a solute
4. diffusion of water from a greater to a lesser water concentration across a selectively permeable membrane
43
Osmotic pressure
a. increases as solute concentration increases.
b. forces water to move toward the higher solute concentration.
c. forces water to move across a semipermeable membrane.
d. can be opposed by hydrostatic pressure.
e. All the answers are correct.
a. increases as solute concentration increases.
44
```
Hemolysis may occur when a blood cell is placed into
hypertonic solution.
homotonic solution.
hypotonic solution.
isotonic solution.
merotonic solution.
```
hypotonic solution
45
```
Red blood cell shrinkage is to ________ as cell bursting is to ________.
isotonic; hypotonic
crenation; hemolysis
lysis; crenation
isotonic; hypertonic
hypotonic; isotonic
```
crenation; hemolysis
46
```
There is a direct correlation between the potency of a general anesthetic such as ether and its ability to
dissolve in lipids.
dissolve in water.
bind to proteins.
interact with carbohydrates.
bind to DNA.
```
dissolve in lipids.
47
The ________ of a membrane indicates how easy it is for substances to cross.
permeability
48
```
Passive movement of a solute by a carrier protein is called __________.
facilitated diffusion
simple diffusion
active transport
sodium-potassium exchange
```
facilitated diffusion
49
Carriers transport solutes across the plasma membrane by __________.
1. opening channel gates that allow solutes to pass
2. forming a pore in the membrane, which allows solutes to pass through
3. changing shape as the solutes bind, causing the solutes to move across the membrane
4. making solutes more soluble in the plasma membrane
3. changing shape as the solutes bind, causing the solutes to move across the membrane
50
\Which of the following conditions would cause (net) glucose to be transported into a cell via facilitated diffusion? Assume ATP is present inside the cell.
a. 5 mM glucose in cytoplasm; 5 mM glucose in extracellular fluid
b. 5.5 mM glucose in cytoplasm; 5.5 mM glucose in extracellular fluid
c. 5 mM glucose in cytoplasm; 0.5 mM glucose in extracellular fluid
d. 0.5 mM glucose in cytoplasm; 5 mM glucose in extracellular fluid
d. 0.5 mM glucose in cytoplasm; 5 mM glucose in extracellular fluid
51
What is the normal direction of calcium transport via the calcium pump?
1. into the cell, with the calcium concentration gradient
2. out of the cell, with the calcium concentration gradient
3. into the cell, against the calcium concentration gradient
4. out of the cell, against its concentration gradient
4. out of the cell, against its concentration gradient
52
```
What is the energy source used by the calcium pump during its normal operation?
the calcium concentration gradient
the calcium pump
the hydrolysis of ATP
the ATP concentration gradient
```
the hydrolysis of ATP
53
What concentration gradients are established and maintained by the sodium-potassium exchange pump?
1. high Na+ concentration in the cytoplasm; high K+ concentration in the extracellular fluid
2. high Na+ concentration in the extracellular fluid; high K+ concentration in the cytoplasm
3. high Na+ and K+ concentrations in the extracellular fluid
4. high Na+ and K+ concentrations in the cytoplasm
2. high Na+ concentration in the extracellular fluid; high K+ concentration in the cytoplasm
54
Which of the following occurs during a single cycle of the sodium-potassium exchange pump?
Three Na+ ions are transported out of the cell.
Two K+ ions are transported out of the cell.
Three K+ ions are transported into the cell.
Three Na+ ions are transported into the cell.
Three Na+ ions are transported out of the cell.
55
The hormone epinephrine (adrenaline) increases the pumping rate of the sodium-potassium exchange pump in skeletal muscles. How would you expect this to affect the concentration of Na+ and K+ in the muscle cytoplasm?
1. The Na+ concentration would increase and the K+ concentration would decrease.
2. The Na+ and K+ concentrations would both decrease.
3. The Na+ concentration would decrease and the K+ concentration would increase.
4. The Na+ and K+ concentrations would both increase.
3. The Na+ concentration would decrease and the K+ concentration would increase.
56
Which of the following best describes the difference between active and passive transport mechanisms?
1. Active mechanisms use energy to move solutes with their concentration gradients. Passive mechanisms move solutes against their concentration gradients.
2. Active mechanisms use energy to move solutes against their concentration gradients. Passive mechanism move solutes with their concentration gradients.
3. Active mechanisms use energy to move solutes out of the cell. Passive mechanisms move solutes into the cell.
4. Active mechanisms use the energy stored in a solute's concentration gradient. Passive mechanisms do not use energy.
2. Active mechanisms use energy to move solutes against their concentration gradients. Passive mechanism move solutes with their concentration gradients.
57
```
Which of these vesicular transport methods expels material from the cell?
receptor-mediated endocytosis
pinocytosis
exocytosis
phagocytosis
```
exocytosis
58
```
Facilitated diffusion differs from simple diffusion in that facilitated diffusion __________.
requires a protein carrier
is an ion pump
doesn't need a gradient
needs ATP
```
requires a protein carrier
59
Facilitated diffusion differs from ordinary diffusion in that
1. the rate of molecular movement is not limited by the number of available carrier molecules.
2. facilitated diffusion never eliminates the concentration gradient.
3. facilitated diffusion moves molecules from an area of higher concentration to lower concentration.
4. facilitated diffusion consumes no ATP.
5. the rate of molecular movement is limited by the number of available carrier molecules.
5. the rate of molecular movement is limited by the number of available carrier molecules.
60
Two types of vesicular transport include
1. pinocytosis and active transport.
2. exocytosis and retrocytosis.
3. endocytosis and exocytosis.
4. passive diffusion and active diffusion.
5. endocytosis and retrocytosis.
3. endocytosis and exocytosis.
61
```
The principal cations in our body fluids are ________ and ________.
chloride; bicarbonate
sodium; chloride
sodium; calcium
calcium; magnesium
sodium; potassium
```
sodium; potassium
62
```
In order to maintain cellular homeostasis, an exchange pump ejects ________ ions from the cell and imports ________ ions.
potassium; sodium
sodium; potassium
calcium; sodium
sodium; calcium
potassium; calcium
```
sodium; potassium
63
```
A defense cell engulfing a bacterium illustrates
receptor-mediated endocytosis.
pinocytosis.
endocytosis.
exocytosis.
phagocytosis.
```
phagocytosis.
64
________ channels can open or close to regulate the passage of materials through the cell membrane.
Gated
65
Membrane-bound proteins that use metabolic energy to move ions across the plasmalemma are called ________.
?
66
```
The cell's transmembrane resting potential was created by __________.
active transport
vesicular transport
facilitated diffusion
osmosis
```
active transport
67
Whenever positive and negative ions have been separated, a(n) ________ will be produced.
potential difference
68
The potential difference across the cell membrane is known as the ________.
transmembrane potential
69
The transmembrane potential in an undisturbed cell is called its ________.
resting potential
70
Mitosis and Cytokinesis
```
interphase
early prophase
late prophase
metaphase
anaphase
telophase
cytokinesis
```
71
```
Which of the following lists, in correct order, the phases of interphase?
G1, prophase, and S
G1, S, and G2
Prophase, metaphase, telophase
S, cytokinesis, mitosis
```
G1, S, and G2
72
Which of the following lists, in correct order, the phases of mitosis?
1. prophase, metaphase, anaphase, cytokinesis
2. prophase, anaphase, metaphase, telophase
3. interphase, prophase, metaphase, anaphase, telophase
4. prophase, metaphase, anaphase, telophase
4. prophase, metaphase, anaphase, telophase
73
```
During which of the following phases does DNA replication occur?
cytokinesis
prophase
Synthesis
mitosis
```
Synthesis (S-phase)
74
```
During which of the following phases does chromatin condense and become chromosomes?
interphase
metaphase
prophase
anaphase
```
prophase
75
```
Which of the following builds new strands of DNA?
DNA helicase
the replication fork
the lagging strand of DNA
DNA polymerase
the leading strand of DNA
```
DNA polymerase
76
Which statement best describes strand characteristics as it relates to DNA replication?
1. The lagging strand is built continuously, and the leading strand is built in pieces.
2. The leading and lagging strands are both built in fragments.
3. The leading strand is built continuously, and the lagging strand is built in pieces.
4. The leading and lagging strands are both built continuously.
3. The leading strand is built continuously, and the lagging strand is built in pieces.
77
```
During DNA replication, which nucleotide will bind to an A nucleotide in the original or parental DNA strand?
T
U
G
C
A
```
T
78
```
Which protein joins together the Okazaki fragments of DNA in the lagging strand?
the replication fork
DNA ligase
the leading strand
RNA
DNA polymerase
```
DNA ligase
79
Which statement about DNA replication is FALSE?
1. DNA ligase adds nucleotides to the lagging strand.
2. The lagging strand is made of a series of fragments that must be joined together to make a continuous strand.
3. Because the two strands of original or parental DNA run in opposite directions, the new strands must be made in different ways.
4. DNA polymerase III builds a new strand by adding DNA nucleotides one at a time.
5. The two strands of original or parental DNA are separated during DNA replication.
1. DNA ligase adds nucleotides to the lagging strand.
80
```
During which phase of the cell cycle does DNA duplication, or replication, take place?
Metaphase
Interphase
Anaphase
Prophase
```
Interphase
81
```
When a double helix of DNA is replicated, two complete helices are formed. Together, these helices are called sister __________.
chromatids
telomeres
chromosomes
centromeres
```
chromatids
82
```
During which phase of mitosis do sister chromatids line up at the center of the cell?
Anaphase
Metaphase
Prophase
Telophase
```
Metaphase
83
```
During which phase of mitosis do the sister chromatids move apart?
Metaphase
Telophase
Anaphase
Prophase
```
Anaphase
84
```
During which phase of mitosis do nuclear envelopes and the nucleoli reappear?
Telophase
Prophase
Metaphase
Anaphase
```
Telophase
85
```
During which phase of mitosis do the nuclear envelope and nucleoli disappear?
Metaphase
Prophase
Telophase
Anaphase
```
Prophase
86
```
What is the name of the process by which the cytoplasm divides in two?
Microtubule shortening
Cytoplasmic streaming
Cytokinesis
Segregation
```
Cytokinesis
87
```
Which enzyme works simultaneously along both DNA strands to synthesize complementary strands of DNA?
RNA polymerase
DNA polymerase
Topoisomerase
Ligase
```
DNA polymerase
88
```
Which phase of mitosis has chromosomes lining up in the center of the cell?
Cytokinesis
Anaphase
Prophase
Metaphase
```
Metaphase
89
If a cell lacked the enzyme DNA polymerase, it could not
form complementary sequences of DNA.
link segments of DNA together.
form spindle fibers.
form a new nuclear membrane during telophase.
form protein.
form complementary sequences of DNA.
90
```
When is DNA replicated?
interkinesis
telophase
metaphase
anaphase
interphase
```
interphase
91
```
The stage in a cell's life cycle in which the cell performs its normal functions and prepares for division is called
telophase.
interphase.
prophase.
anaphase.
metaphase.
```
interphase.
92
During mitosis, two daughter cells form, each of which has
1. twice as many chromosomes as the original cell.
2. the same number of chromosomes as the original cell.
3. half as many chromosomes as the original cell.
4. a different number of chromosomes than the original cell.
5. a lesser number of chromosomes than the original cell.
2. the same number of chromosomes as the original cell.
93
The correct order of phases in cell division is:
1. interphase, prophase, metaphase, anaphase, telophase
2. telophase, anaphase, metaphase, interphase, prophase
3. metaphase, anaphase, interphase, prophase, telophase
4. prophase, interphase, anaphase, metaphase, telophase
5. interphase, prophase, anaphase, metaphase, telophase
1. interphase, prophase, metaphase, anaphase, telophase
94
Nuclear division of somatic cells is known as ________.
mitosis
95
```
Unlike normal cells, cancer cells are never __________.
misshapen
benign
very small
very large
```
benign
96
```
Differentiation requires __________ of particular genes to produce populations with __________ capabilities that form tissues.
activation; unlimited
inactivation; limited
inactivation; unlimited
activation; limited
```
inactivation; limited
97
The enzyme ________ is required for the synthesis of mRNA.
RNA polymerase
