Question 1

A cell with nuclear lamins that cannot be phosphorylated in M phase will be unable to

Accepted Answer

A) reassemble its nuclear envelope at telophase. 
B) disassemble its nuclear lamina at prometaphase. 
C) begin to assemble a mitotic spindle. 
D) condense its chromosomes at prophase. 
A) reassemble its nuclear envelope at telophase. 
B) disassemble its nuclear lamina at prometaphase. 
C) begin to assemble a mitotic spindle. 
D) condense its chromosomes at prophase.

Question 2

Which of the following precede the re-formation of the nuclear envelope during M phase in animal cells?

Accepted Answer

A) assembly of the contractile ring 
B) decondensation of chromosomes 
C) reassembly of the nuclear lamina 
D) transcription of nuclear genes 
A) assembly of the contractile ring 
B) decondensation of chromosomes 
C) reassembly of the nuclear lamina 
D) transcription of nuclear genes

Question 3

Levels of Cdk activity change during the cell cycle, in part because

Accepted Answer

A) the Cdks phosphorylate each other. 
B) the Cdks activate the cyclins. 
C) Cdk degradation precedes entry into the next phase of the cell cycle. 
D) cyclin activity change during the cycle. 
A) the Cdks phosphorylate each other. 
B) the Cdks activate the cyclins. 
C) Cdk degradation precedes entry into the next phase of the cell cycle. 
D) cyclin activity change during the cycle.

Question 4

Which of the following statements is TRUE?

Accepted Answer

A) Anaphase A must be completed before anaphase B can take place. 
B) In cells in which anaphase B predominates, the spindle will elongate much less than in cells in which anaphase A dominates. 
C) In anaphase A, both kinetochore and interpolar microtubules shorten. 
D) In anaphase B, microtubules associated with the cell cortex shorten. 
A) Anaphase A must be completed before anaphase B can take place. 
B) In cells in which anaphase B predominates, the spindle will elongate much less than in cells in which anaphase A dominates. 
C) In anaphase A, both kinetochore and interpolar microtubules shorten. 
D) In anaphase B, microtubules associated with the cell cortex shorten.

Question 5

A mutant yeast strain stops proliferating when shifted from 25°C to 37°C.When these cells are analyzed at the two different temperatures, using a machine that sorts cells according to the amount of DNA they contain, the graphs in Figure 18-2 are obtained.   Figure 18-2
Which of the following would NOT explain the results with the mutant?

Accepted Answer

A) inability to initiate DNA replication 
B) inability to begin M phase 
C) inability to activate proteins needed to enter S phase 
D) inappropriate production of a signal that causes the cells to remain in G1 
A) inability to initiate DNA replication 
B) inability to begin M phase 
C) inability to activate proteins needed to enter S phase 
D) inappropriate production of a signal that causes the cells to remain in G1

Question 6

Consider an animal cell that has eight chromosomes (four pairs of homologous chromosomes) in G1 phase.How many of each of the following structures will the cell have at mitotic prophase?
A.sister chromatids
B.centromeres
C.kinetochores
D.centrosomes
E.centrioles

Accepted Answer

A-16; B-16

Question 7

What is the cause of the massive amount of programmed cell death of nerve cells (neurons) that occurs in the developing vertebrate nervous system, and what purpose does it serve?

Accepted Answer

Immature neurons are produced in excess

Question 8

For each of the following sentences, fill in the blanks with the best word or phrase selected from the list below.Not all words or phrases will be used; each word or phrase should be used only once.
$\begin{array}{lll}
\text { anaphase } & \text { differentiation } & \text { myostatin } \
\text { annihilation } & \mathrm{G}_{0} & \text { nourishment } \
\text { arrestase } & \mathrm{G}_{1} & \text { nutrition } \
\text { Bcl2 } & \mathrm{G}_{2} & \text { phosphatases } \
\text { biosynthetic } & \text { growth factors } & \text { proliferation } \
\text { cyclin } & \text { interphase } & \text { receptor } \
\text { cascades } & \text { ligand } & \mathrm{S} \
\text { caspase } & \mathrm{M} & \text { survival factors } \
\text { Cdk } & \text { mitogens } & \text { transcription }
\end{array}$

The survival, __________, and size of each cell in an animal are controlled by extracellular signal molecules secreted by neighboring and distant cells.Many of these signal molecules bind to a cell-surface __________ and trigger various intracellular signaling pathways.One class of signal molecules, called __________, stimulates cell division by releasing the molecular brakes that keep cells in the __________or __________ phase of the cell cycle.Members of a second class of signal molecules are called __________, because they stimulate cell growth and an increase in cell mass.The third class of signal molecules, called __________, inhibits apoptosis by regulating members of the __________ family of proteins.In addition to such stimulatory factors, some signal proteins, such as __________ act negatively on other cells, inhibiting their survival, growth, or proliferation.

Accepted Answer

The survival, proliferation, and size of

Question 9

Which of the following statements about the cell cycle is FALSE?

Accepted Answer

A) Once a cell decides to enter the cell cycle, the time from start to finish is the same in all eukaryotic cells. 
B) An unfavorable environment can cause cells to arrest in G1. 
C) A cell has more DNA during G2 than it did in G1. 
D) The cleavage divisions that occur in an early embryo have short G1 and G2 phases. 
A) Once a cell decides to enter the cell cycle, the time from start to finish is the same in all eukaryotic cells. 
B) An unfavorable environment can cause cells to arrest in G1. 
C) A cell has more DNA during G2 than it did in G1. 
D) The cleavage divisions that occur in an early embryo have short G1 and G2 phases.

Question 10

Which of the following statements about kinetochores is TRUE?

Accepted Answer

A) Kinetochores assemble onto chromosomes during late prophase. 
B) Kinetochores contain DNA-binding proteins that recognize sequences at the telomere of the chromosome. 
C) Kinetochore proteins bind to the tubulin molecules at the minus end of microtubules. 
D) Kinetochores assemble on chromosomes that lack centromeres. 
A) Kinetochores assemble onto chromosomes during late prophase. 
B) Kinetochores contain DNA-binding proteins that recognize sequences at the telomere of the chromosome. 
C) Kinetochore proteins bind to the tubulin molecules at the minus end of microtubules. 
D) Kinetochores assemble on chromosomes that lack centromeres.

Question 11

Match between columns
                        Premises: The centromere nucleates a radial array of microtubules called an aster, and its duplication is triggered by S-Cdk.

Each centrosome contains a pair of centrioles and hundreds of $ \mathrm{Y} $-tubulin rings that nucleate the growth of microtubules.

Cohesins are required to make the chromosomes more compact and thus to prevent tangling between different chromosomes.
A)open-ended question

Sister chromatids are held together by condensins from the time they arise by DNA replication until the time they separate at anaphase.

Microtubule-dependent motor proteins and microtubule polymerization and depolymerization are mainly responsible for the organized movements of chromosomes during mitosis.

Accepted Answer

The Answer of True and False is...

Question 12

Before a cell can enter M phase, two structures from Figure 18-12 must be duplicated.Write the letters corresponding to the lines pointing to these structures, and write the names of the structures next to the letters.   
Figure 18-12

Accepted Answer

A.centroso

Question 13

You engineer yeast cells that express the M cyclin during S phase by replacing the gene regulatory sequences of the M cyclin gene with those of the S cyclin gene.Keeping in mind that yeast cells have one common Cdk that binds to all cyclins, which of the following outcomes is LEAST likely during this experiment?

Accepted Answer

A) There will be both M cyclin-Cdk and S cyclin-Cdk complexes in the cell during S phase. 
B) Some substrates that are normally phosphorylated in M phase will now be phosphorylated in S phase. 
C) G1 cyclin-Cdks will be activated earlier in G1. 
D) S-Cdk targets will be phosphorylated during S phase. 
A) There will be both M cyclin-Cdk and S cyclin-Cdk complexes in the cell during S phase. 
B) Some substrates that are normally phosphorylated in M phase will now be phosphorylated in S phase. 
C) G1 cyclin-Cdks will be activated earlier in G1. 
D) S-Cdk targets will be phosphorylated during S phase.

Question 14

Which organelle fragments during mitosis?

Accepted Answer

A) endoplasmic reticulum 
B) Golgi apparatus 
C) mitochondrion 
D) chloroplast 
A) endoplasmic reticulum 
B) Golgi apparatus 
C) mitochondrion 
D) chloroplast

Question 15

Which of the following does not occur during M phase in animal cells?

Accepted Answer

A) growth of the cell 
B) condensation of chromosomes 
C) breakdown of nuclear envelope 
D) attachment of chromosomes to microtubules 
A) growth of the cell 
B) condensation of chromosomes 
C) breakdown of nuclear envelope 
D) attachment of chromosomes to microtubules

Question 16

Apoptosis differs from necrosis in that necrosis

Accepted Answer

A) requires the reception of an extracellular signal. 
B) causes DNA to fragment. 
C) causes cells to swell and burst, whereas apoptotic cells shrink and condense. 
D) involves a caspase cascade. 
A) requires the reception of an extracellular signal. 
B) causes DNA to fragment. 
C) causes cells to swell and burst, whereas apoptotic cells shrink and condense. 
D) involves a caspase cascade.

Question 17

A friend declares that chromosomes are held at the metaphase plate by microtubules that push on each chromosome from opposite sides.Which of the following observations does not support your belief that the microtubules are pulling on the chromosomes?

Accepted Answer

A) the jiggling movement of chromosomes at the metaphase plate 
B) the way in which chromosomes behave when the attachment between sister chromatids is severed 
C) the way in which chromosomes behave when the attachment to one kinetochore is severed 
D) the shape of chromosomes as they move toward the spindle poles at anaphase 
A) the jiggling movement of chromosomes at the metaphase plate 
B) the way in which chromosomes behave when the attachment between sister chromatids is severed 
C) the way in which chromosomes behave when the attachment to one kinetochore is severed 
D) the shape of chromosomes as they move toward the spindle poles at anaphase

Question 18

Which of the following statements is FALSE?

Accepted Answer

A) Cytokinesis in plant cells is mediated by the microtubule cytoskeleton. 
B) Small membrane vesicles derived from the Golgi apparatus deliver new cell-wall material for the new wall of the dividing cell. 
C) The phragmoplast forms from the remains of interpolar microtubules of the mitotic spindle. 
D) Motor proteins walking along the cytoskeleton are important for the contractile ring that guides formation of the new cell wall. 
A) Cytokinesis in plant cells is mediated by the microtubule cytoskeleton. 
B) Small membrane vesicles derived from the Golgi apparatus deliver new cell-wall material for the new wall of the dividing cell. 
C) The phragmoplast forms from the remains of interpolar microtubules of the mitotic spindle. 
D) Motor proteins walking along the cytoskeleton are important for the contractile ring that guides formation of the new cell wall.

Question 19

The Retinoblastoma (Rb) protein blocks cells from entering the cell cycle by

Accepted Answer

A) phosphorylating Cdk. 
B) marking cyclins for destruction by proteolysis. 
C) inhibiting cyclin transcription. 
D) activating apoptosis. 
A) phosphorylating Cdk. 
B) marking cyclins for destruction by proteolysis. 
C) inhibiting cyclin transcription. 
D) activating apoptosis.

Question 20

Which stage of mitosis in an animal cell does each part of Figure 18-9 represent?   
Figure 18-9

Accepted Answer

A-telophase; B-proph

A cell with nuclear lamins that cannot be phosphorylated in M phase will be unable to

Which of the following precede the re-formation of the nuclear envelope during M phase in animal cells?

Levels of Cdk activity change during the cell cycle, in part because

Which of the following statements is TRUE?

Consider an animal cell that has eight chromosomes (four pairs of homologous chromosomes) in G₁ phase.How many of each of the following structures will the cell have at mitotic prophase? A.sister chromatids B.centromeres C.kinetochores D.centrosomes E.centrioles

What is the cause of the massive amount of programmed cell death of nerve cells (neurons) that occurs in the developing vertebrate nervous system, and what purpose does it serve?

Which of the following statements about the cell cycle is FALSE?

Which of the following statements about kinetochores is TRUE?

Before a cell can enter M phase, two structures from Figure 18-12 must be duplicated.Write the letters corresponding to the lines pointing to these structures, and write the names of the structures next to the letters. Figure 18-12

Which organelle fragments during mitosis?

Which of the following does not occur during M phase in animal cells?

Apoptosis differs from necrosis in that necrosis

A friend declares that chromosomes are held at the metaphase plate by microtubules that push on each chromosome from opposite sides.Which of the following observations does not support your belief that the microtubules are pulling on the chromosomes?

Which of the following statements is FALSE?

The Retinoblastoma (Rb) protein blocks cells from entering the cell cycle by

Which stage of mitosis in an animal cell does each part of Figure 18-9 represent? Figure 18-9

Cells: The Fundamental Units of Life

Chemical Components of Cells

Energy, Catalysis, and Biosynthesis

Protein Structure and Function

DNA and Chromosomes

DNA Replication and Repair

From DNA to Protein

Control of Gene Expression

How Genes and Genomes Evolve

Analyzing the Structure and Function of Genes

Membrane Structure

Transport Across Cell Membranes

How Cells Obtain Energy From Food

Energy Generation in Mitochondria and Chloroplasts

Intracellular Compartments and Protein Transport

Cell Signaling

Cytoskeleton

Sexual Reproduction and the Power of Genetics

Cell Communities: Tissues, Stem Cells, and Cancer

Filters

Exam 18: The Cell-Division Cycle

A cell with nuclear lamins that cannot be phosphorylated in M phase will be unable to

Which of the following precede the re-formation of the nuclear envelope during M phase in animal cells?

Levels of Cdk activity change during the cell cycle, in part because

Which of the following statements is TRUE?

Consider an animal cell that has eight chromosomes (four pairs of homologous chromosomes) in G1 phase.How many of each of the following structures will the cell have at mitotic prophase? A.sister chromatids B.centromeres C.kinetochores D.centrosomes E.centrioles

What is the cause of the massive amount of programmed cell death of nerve cells (neurons) that occurs in the developing vertebrate nervous system, and what purpose does it serve?

Which of the following statements about the cell cycle is FALSE?

Which of the following statements about kinetochores is TRUE?

Before a cell can enter M phase, two structures from Figure 18-12 must be duplicated.Write the letters corresponding to the lines pointing to these structures, and write the names of the structures next to the letters. Figure 18-12

Which organelle fragments during mitosis?

Which of the following does not occur during M phase in animal cells?

Apoptosis differs from necrosis in that necrosis

A friend declares that chromosomes are held at the metaphase plate by microtubules that push on each chromosome from opposite sides.Which of the following observations does not support your belief that the microtubules are pulling on the chromosomes?

Which of the following statements is FALSE?

The Retinoblastoma (Rb) protein blocks cells from entering the cell cycle by

Which stage of mitosis in an animal cell does each part of Figure 18-9 represent? Figure 18-9

Cells: The Fundamental Units of Life

Chemical Components of Cells

Energy, Catalysis, and Biosynthesis

Protein Structure and Function

DNA and Chromosomes

DNA Replication and Repair

From DNA to Protein

Control of Gene Expression

How Genes and Genomes Evolve

Analyzing the Structure and Function of Genes

Membrane Structure

Transport Across Cell Membranes

How Cells Obtain Energy From Food

Energy Generation in Mitochondria and Chloroplasts

Intracellular Compartments and Protein Transport

Cell Signaling

Cytoskeleton

Sexual Reproduction and the Power of Genetics

Cell Communities: Tissues, Stem Cells, and Cancer

Filters

Consider an animal cell that has eight chromosomes (four pairs of homologous chromosomes) in G₁ phase.How many of each of the following structures will the cell have at mitotic prophase? A.sister chromatids B.centromeres C.kinetochores D.centrosomes E.centrioles