Cell Cycle and Cell Division Quiz

1.

1 point

Which of the following is true of transcription factors? (Chapter 11)

They control gene expression.

They initiate the epinephrine response in animal cells.

They regulate the synthesis of DNA in response to a signal.

They regulate the synthesis of lipids in the cytoplasm.

They transcribe ATP into cAMP.

2.

1 point

Which of the following occurs in meiosis but not in mitosis? (Chapter 13)

Chromosome replication

Alignment of chromosomes at the equator

Production of daughter cells

Condensation of chromatin

Synapsis of chromosomes

3.

1 point

Why is ATP an important molecule in metabolism? (Chapter 8)

It is one of the four building blocks for DNA synthesis.

Its terminal phosphate bond has higher energy than the other two.

It provides energy coupling between exergonic and endergonic reactions.

Its hydrolysis provides an input of free energy for exergonic reactions.

Its terminal phosphate group contains a strong covalent bond that, when hydrolyzed, releases free energy.

4.

1 point

In a human karyotype, chromosomes are arranged in 23 pairs. If one of these pairs is chosen, such as pair 14, which of the following do the two chromosomes of the pair have in common? (Chapter 13)

Length, centromere position, staining pattern, and traits coded for by their genes.

Length and position of the centromere only.

Length, centromere position, staining pattern, and DNA sequences.

They have nothing in common except they are X-shaped.

Length, centromere position, and staining pattern only.

5.

1 point

Adenylyl cyclase has the opposite effect of which of the following? (Chapter 11)

Protein phosphatase

GTPase

Phosphodiesterase

Phosphorylase

Protein kinase

6.

1 point

The following question is based on the reaction A + B ↔ C + D shown in Figure 8.1. Which of the following represents the ΔG of the reaction in Figure 8.1? (Chapter 8)

a

b

c

d

e

7.

1 point

GTPase activity is involved in the regulation of signal transduction because it: (Chapter 11)

Increases the available concentration of phosphate.

Phosphorylates protein kinases.

Decreases the amount of G protein in the membrane.

Hydrolyzes GTP binding to G protein.

Converts CGMP to GTP.

8.

1 point

Refer to the drawings of a single pair of homologous chromosomes in Figure 13.2 as they might appear during various stages of either mitosis or meiosis.
Which diagram represents anaphase I of meiosis? (Chapter 13)

I

IV

V

II

VI

9.

1 point

Which of the following defines a genome? (Chapter 13)

Representation of a complete set of a cell's polypeptides.

The complete set of a species' polypeptides.

A karyotype.

The complete set of an organism's genes.

The complete set of an organism's polypeptides.

10.

1 point

If there are 20 chromatids in a cell, how many centromeres are there? (Chapter 12)

10

20

30

40

80

11.

1 point

Which of the following is true concerning cancer cells? (Chapter 12)

When they stop dividing, they do so at random points in the cell cycle; they are not subject to cell cycle controls; and they do not exhibit density-dependent inhibition when growing in culture.

They are not subject to cell cycle controls.

When they stop dividing, they do so at random points in the cell cycle.

They do not exhibit density-dependent inhibition when growing in culture.

When they stop dividing, they do so at random points in the cell cycle, and they are not subject to cell cycle controls.

12.

1 point

Lipid-soluble signaling molecules, such as testosterone, cross the membranes of all cells but affect only target cells because: (Chapter 11)

Only in target cells is testosterone able to initiate the phosphorylation cascade leading to activated transcription factor.

Only target cells possess the cytosolic enzymes that transduce the testosterone.

Intracellular receptors are present only in target cells.

Only target cells retain the appropriate DNA segments.

Most cells lack the Y chromosome required.

13.

1 point

A human cell containing 22 autosomes and a Y chromosome is: (Chapter 13)

A zygote

An egg

a sperm

A somatic cell of a female

A somatic cell of a male

14.

1 point

Phosphofructokinase is an allosteric enzyme that catalyzes the conversion of fructose 6-phosphate to fructose 1,6-bisphosphate, an early step of glycolysis. In the presence of oxygen, an increase in the amount of ATP in a cell would be expected to (Chapter 9)

inhibit the enzyme and thus slow the rates of glycolysis and the citric acid cycle.

inhibit the enzyme and thus increase the rates of glycolysis and the citric acid cycle.

activate the enzyme and thus slow the rates of glycolysis and the citric acid cycle.

inhibit the enzyme and thus increase the rate of glycolysis and the concentration of citrate.

activate the enzyme and increase the rates of glycolysis and the citric acid cycle.

15.

1 point

Independent assortment of chromosomes occurs. (Chapter 13)

The statement is true for mitosis only.

The statement is true for meiosis I only.

The statement is true for mitosis and meiosis II.

The statement is true for meiosis II only.

The statement is true for mitosis and meiosis I.

16.

1 point

Which of the following statements is representative of the second law of thermodynamics? (Chapter 8)

Conversion of energy from one form to another is always accompanied by some gain of free energy.

Cells require a constant input of energy to maintain their high level of organization.

Without an input of energy, organisms would tend toward decreasing entropy.

Heat represents a form of energy that can be used by most organisms to do work.

Every energy transformation by a cell decreases the entropy of the universe.

17.

1 point

One of the major categories of receptors in the plasma membrane reacts by forming dimers, adding phosphate groups, and then activating relay proteins. Which type does this? (Chapter 11)

Ligand-gated ion channels

G protein-coupled receptors

Receptor tyrosine kinases

Steroid receptors

18.

1 point

The centromere is a region in which: (Chapter 12)

New spindle microtubules form at either end.

Chromosomes are grouped during telophase.

Metaphase chromosomes become aligned at the metaphase plate.

The nucleus is located prior to mitosis.

Chromatids remain attached to one another until anaphase.

19.

1 point

Homologous chromosomes move toward opposite poles of a dividing cell during: (Chapter 13)

Meiosis II

Mitosis

Meiosis I

Fertilization

Binary fission

20.

1 point

What are scaffolding proteins? (Chapter 11)

Relay proteins that orient receptors and their ligands in appropriate directions to facilitate their complexing.

Large molecules to which several relay proteins attach to facilitate cascade effects.

Ladderlike proteins that allow receptor-ligand complexes to climb through cells from one position to another.

Proteins that can reach into the nucleus of a cell to affect transcription.

Microtubular protein arrays that allow lipid-soluble hormones to get from the cell membrane to the nuclear pores.

21.

1 point

Why is glycolysis considered by evolutionary theory to be one of the first metabolic pathways to have evolved? (Chapter 9)

It produces much less ATP than does oxidative phosphorylation.

It is found in prokaryotic cells but not in eukaryotic cells.

It requires the presence of membrane-enclosed cell organelles found only in eukaryotic cells.

It relies on chemiosmosis, which is a metabolic mechanism present only in the first cells' prokaryotic cells.

It does not involve organelles or specialized structures, does not require oxygen, and is present in most organisms.

22.

1 point

For anaphase to begin, which of the following must occur? (Chapter 12)

Cohesin must be cleaved enzymatically.

Cohesin must attach the sister chromatids to each other.

Kinetochores must attach to the metaphase plate.

Spindle microtubules must begin to depolymerize.

Chromatids must lose their kinetochores.

23.

1 point

The function of phosphatases in signal transduction is best described as to: (Chapter 11)

Move the phosphate group of the transduction pathway to the next molecule of a series.

Inactivate protein kinases and turn off the signal transduction.

Amplify the second messengers such as camp.

Amplify the transduction signal so it affects multiple transducers.

Prevent a protein kinase from being reused when there is another extracellular signal.

24.

1 point

Consider this pathway: epinephrine → G protein-coupled receptor → G protein → adenylyl cyclase → camp. Identify the second messenger. (Chapter 11)

Camp

G protein-coupled receptor

Adenylyl cyclase

GTP

G protein

25.

1 point

Why is apoptosis potentially threatening to the healthy "neighbors" of a dying cell? (Chapter 11)

Lysosomal enzymes exiting the dying cell would damage surrounding cells.

Cell death would usually spread from one cell to the next via paracrine signals.

Neighboring cells would activate immunological responses.

Bits of membrane from the dying cell could merge with neighbors and bring in foreign receptors.

Released cellular energy would interfere with the neighbors' energy budget.

26.

1 point

The activation of receptor tyrosine kinases is characterized by: (Chapter 11)

A phosphorylation cascade.

Dimerization and phosphorylation.

GTP hydrolysis.

Channel protein shape change.

Dimerization and IP3 binding.

27.

1 point

Why do neurons and some other specialized cells divide infrequently? (Chapter 12)

They no longer carry receptors for signal molecules.

They show a drop in MPF concentration.

They have been shunted into G0.

They no longer have active nuclei.

They can no longer bind CDK to cyclin.

28.

1 point

Where do apoptotic signals come from? (Chapter 11)

The nucleus only

The ER only

Ligand binding only

Mitochondrial protein leakage only

All of the above

29.

1 point

When a neuron responds to a particular neurotransmitter by opening gated ion channels, the neurotransmitter is serving as which part of the signal pathway? (Chapter 11)

Signal molecule

Relay molecule

Transducer

Receptor

Endocrine molecule

30.

1 point

After telophase I of meiosis, the chromosomal makeup of each daughter cell is: (Chapter 13)

Diploid, and the chromosomes are each composed of a single chromatid.

Haploid, and the chromosomes are each composed of two chromatids.

Haploid, and the chromosomes are each composed of a single chromatid.

Tetraploid, and the chromosomes are each composed of two chromatids.

Diploid, and the chromosomes are each composed of two chromatids.

31.

1 point

Why do chromosomes coil during mitosis? (Chapter 12)

To allow the chromosomes to fit within the nuclear envelope.

To increase their potential energy.

To allow the sister chromatids to remain attached.

To provide for the structure of the centromere.

To allow the chromosomes to move without becoming entangled and breaking.

32.

1 point

Cells from an advanced malignant tumor most often have very abnormal chromosomes, and often an abnormal total number of chromosomes. Why might this occur? (Chapter 12)

Chromosomally abnormal cells can still go through cell cycle checkpoints.

Transformation introduces new chromosomes into cells.

Cancer cells are no longer anchorage dependent.

Cancer cells are no longer density dependent.

Chromosomally abnormal cells still have normal metabolism.

33.

1 point

Where do the microtubules of the spindle originate during mitosis in both plant and animal cells? (Chapter 12)

Centromere

Chromatid

Kinetochore

Centriole

Centrosome

34.

1 point

Which of the following does not occur during mitosis? (Chapter 12)

Spindle formation

Replication of the DNA

Separation of the spindle poles

Separation of sister chromatids

Condensation of the chromosomes

35.

1 point

What is a cleavage furrow? (Chapter 12)

The metaphase plate where chromosomes attach to the spindle.

The separation of divided prokaryotes.

A groove in the plasma membrane between daughter nuclei.

A ring of vesicles forming a cell plate.

The space created between two chromatids during anaphase.

36.

1 point

Which of the following is a protein maintained at constant levels throughout the cell cycle that requires cyclin to become catalytically active? (Chapter 12)

PDGF

MPF

CDK

Cyclin

Protein kinase

37.

1 point

Testosterone functions inside a cell by: (Chapter 11)

Coordinating a phosphorylation cascade that increases spermatogenesis.

Acting as a steroid signal receptor that activates ion channel proteins.

Acting as a signal receptor that activates tyrosine kinases.

Binding with a receptor protein that enters the nucleus and activates specific genes.

Becoming a second messenger that inhibits adenylyl cyclase.

38.

1 point

According to the induced fit hypothesis of enzyme catalysis, which of the following is correct? (Chapter 8)

Some enzymes change their structure when activators bind to the enzyme.

The binding of the substrate depends on the shape of the active site.

The active site creates a microenvironment ideal for the reaction.

A competitive inhibitor can outcompete the substrate for the active site.

The binding of the substrate changes the shape of the enzyme's active site.

39.

1 point

The molecule that functions as the reducing agent (electron donor) in a redox or oxidation-reduction reaction (Chapter 9)

neither gains nor loses electrons, but gains or loses potential energy.

gains electrons and loses potential energy.

loses electrons and gains potential energy.

loses electrons and loses potential energy.

gains electrons and gains potential energy.

40.

1 point

After which checkpoint is the cell first committed to continue the cell cycle through M? (Chapter 12)

S

G2

G0

Previous M

G1