Question 1

Which of the following statements about why multicellular organisms need cell division is generally NOT true?

Accepted Answer

A)  As an organism matures, it needs more cells. 
B)  As an organism matures, it needs different kinds of cells. 
C)  As an organism matures, it needs to replace the DNA in each of its cells. 
D)  As an organism matures, it needs to replace worn-out cells. 
A)  As an organism matures, it needs more cells. 
B)  As an organism matures, it needs different kinds of cells. 
C)  As an organism matures, it needs to replace the DNA in each of its cells. 
D)  As an organism matures, it needs to replace worn-out cells. C

Question 2

Some human cells (skeletal muscle,for example)are multinucleated and originate when uninucleated cells fuse.What cell division process alone could produce a multinucleated cell?

Accepted Answer

A)  a cell undergoing mitosis but not cytokinesis 
B)  a cell undergoing cytokinesis but not mitosis 
C)  a cell arresting after meiosis I 
D)  fertilization of a haploid egg by a diploid sperm 
A)  a cell undergoing mitosis but not cytokinesis 
B)  a cell undergoing cytokinesis but not mitosis 
C)  a cell arresting after meiosis I 
D)  fertilization of a haploid egg by a diploid sperm A

Question 3

The distribution of DNA into homologous pairs of chromosomes allows

Accepted Answer

A)  cells to reduce their number of chromosomes by half during meiosis. 
B)  a cell to begin meiosis with only half of its DNA. 
C)  sex chromosomes to exist in some cells. 
D)  microtubules to attach to only half of the chromosomes. 
A)  cells to reduce their number of chromosomes by half during meiosis. 
B)  a cell to begin meiosis with only half of its DNA. 
C)  sex chromosomes to exist in some cells. 
D)  microtubules to attach to only half of the chromosomes. A

Question 4

Sexual and asexual reproduction can both offer distinct advantages under certain circumstances.In which of the following situations would asexual reproduction NOT be advantageous?

Accepted Answer

A)  Decomposers discover a dolphin carcass that has recently drifted to the ocean floor. 
B)  A persistently cooling climate results in a significant increase in average winter snow depth. 
C)  A cut breaches the skin's defensive ability, and infectious pathogens invade the injury. 
D)  Coastal currents, water temperature, nutrient concentrations, and light intensity temporarily combine to produce ideal growth conditions for marine phytoplankton. 
A)  Decomposers discover a dolphin carcass that has recently drifted to the ocean floor. 
B)  A persistently cooling climate results in a significant increase in average winter snow depth. 
C)  A cut breaches the skin's defensive ability, and infectious pathogens invade the injury. 
D)  Coastal currents, water temperature, nutrient concentrations, and light intensity temporarily combine to produce ideal growth conditions for marine phytoplankton.

Question 5

In what way does a human somatic cell differ from a human gamete?

Accepted Answer

A)  Somatic cells are diploid (n), whereas gametes are haploid (2n). 
B)  Somatic cells are created by meiosis, whereas gametes are created by mitosis. 
C)  Somatic cells differentiate into at least 220 cell types, whereas there are only two types of gametes. 
D)  Somatic cells can spontaneously change into gametes, but gametes must remain gametes. 
A)  Somatic cells are diploid (n), whereas gametes are haploid (2n). 
B)  Somatic cells are created by meiosis, whereas gametes are created by mitosis. 
C)  Somatic cells differentiate into at least 220 cell types, whereas there are only two types of gametes. 
D)  Somatic cells can spontaneously change into gametes, but gametes must remain gametes.

Question 6

In animals,only meiosis can lead to the production of new ________.

Accepted Answer

A)  skin 
B)  brain 
C)  sperm 
D)  liver 
A)  skin 
B)  brain 
C)  sperm 
D)  liver

Question 7

Parthenogenesis is a type of asexual reproduction in which embryos can be established and grow without fertilization.Essentially,this means that an embryo develops from an unfertilized egg.What is the most likely reason why the parthenogenetic whiptail lizards of the desert Southwest create no new genetic combinations during crossing-over,whereas other animals do?

Accepted Answer

A)  In this species, all the crossovers are double, eventually restoring each chromosome to its
Original condition. 
B)  The lizards have no homologous chromosomes. In this species, crossing-over takes place between genetically identical sister chromatids; therefore, no changes occur. 
C)  Parthenogenetic species forgo meiosis I, the stage in which crossing-over normally occurs. 
D)  Accumulated mutations within this species have modified the centromeres, disrupted the formation of a bivalent, and prevented crossing-over from taking place. 
A)  In this species, all the crossovers are double, eventually restoring each chromosome to its
Original condition. 
B)  The lizards have no homologous chromosomes. In this species, crossing-over takes place between genetically identical sister chromatids; therefore, no changes occur. 
C)  Parthenogenetic species forgo meiosis I, the stage in which crossing-over normally occurs. 
D)  Accumulated mutations within this species have modified the centromeres, disrupted the formation of a bivalent, and prevented crossing-over from taking place.

Question 8

The bivalents of homologous chromosomes undergo crossing-over.What is the significance of this process?

Accepted Answer

A)  Two copies of the same chromosome are able to become part of the same gamete. 
B)  The resulting gametes will have different gene combinations than those of their parent cells. 
C)  The bivalent chromosomes are able to exchange genetic material with other pairs of chromosomes. 
D)  The gametes that are produced will have twice as many chromosomes as the parent cells. 
A)  Two copies of the same chromosome are able to become part of the same gamete. 
B)  The resulting gametes will have different gene combinations than those of their parent cells. 
C)  The bivalent chromosomes are able to exchange genetic material with other pairs of chromosomes. 
D)  The gametes that are produced will have twice as many chromosomes as the parent cells.

Question 9

All cells in a human body undergo the process of meiosis.

Accepted Answer

A) True 
 B)False

Question 10

The procedure that enables a young woman to freeze her eggs when she is single and save them for later use,up to age 50,is called ________.

Accepted Answer

A) True 
 B)False

Question 11

A zygote contains 16 chromosomes.The diploid number of this cell is ________ [2n = ?].

Accepted Answer

The answer of A zygote contains 16 chromosomes.The diploid number...

Question 12

The mitotic spindle guides the movement of chromosomes during certain stages of mitosis.

Accepted Answer

A) True 
 B)False

Question 13

During the S phase,the cell

Accepted Answer

A)  duplicates its DNA. 
B)  increases in size to prepare for DNA synthesis. 
C)  completes its preparation for mitosis. 
D)  rests between divisions. 
A)  duplicates its DNA. 
B)  increases in size to prepare for DNA synthesis. 
C)  completes its preparation for mitosis. 
D)  rests between divisions.

Question 14

By the time a cell enters meiosis II,it has

Accepted Answer

A)  become haploid. 
B)  re-formed bivalents. 
C)  temporarily become diploid. 
D)  rejoined its maternal homologue. 
A)  become haploid. 
B)  re-formed bivalents. 
C)  temporarily become diploid. 
D)  rejoined its maternal homologue.

Question 15

Microtubules attach to plaques of protein on chromosomes; these plaques are called ________.

Accepted Answer

The answer of Microtubules attach to plaques of protein on...

Question 16

If a skin cell of an organism has 24 chromosomes,its gametes must also have 24 chromosomes.

Accepted Answer

A) True 
 B)False

Question 17

Lily plants sometimes have twice as many chromosomes per cell as their parent plants.Which of the following statements explains how this phenomenon might have happened?

Accepted Answer

A)  The lily's sister chromatids failed to separate during meiosis. 
B)  The lily's chromosome number went from 2n to 1n. 
C)  The lily's gametes fused during mitosis. 
D)  The parent plant lost half of its chromosomes during mitosis. 
A)  The lily's sister chromatids failed to separate during meiosis. 
B)  The lily's chromosome number went from 2n to 1n. 
C)  The lily's gametes fused during mitosis. 
D)  The parent plant lost half of its chromosomes during mitosis.

Question 18

The successful union of one male gamete and one female gamete forms a new single cell known as a

Accepted Answer

A)  histone. 
B)  zygote. 
C)  vesicle. 
D)  gametocyte. 
A)  histone. 
B)  zygote. 
C)  vesicle. 
D)  gametocyte.

Question 19

The spindle microtubules break down and new nuclear envelopes form during the mitotic stage called ________.

Accepted Answer

The answer of The spindle microtubules break down and new...

Question 20

During meiosis I,the microtubules from each spindle pole attach to only one member of a bivalent,generally the one closest to that spindle pole.

Accepted Answer

A) True 
 B)False

Exam 7: Cell Division

Which of the following statements about why multicellular organisms need cell division is generally NOT true?

Some human cells (skeletal muscle,for example)are multinucleated and originate when uninucleated cells fuse.What cell division process alone could produce a multinucleated cell?

The distribution of DNA into homologous pairs of chromosomes allows

Sexual and asexual reproduction can both offer distinct advantages under certain circumstances.In which of the following situations would asexual reproduction NOT be advantageous?

In what way does a human somatic cell differ from a human gamete?

In animals,only meiosis can lead to the production of new ________.

The bivalents of homologous chromosomes undergo crossing-over.What is the significance of this process?

All cells in a human body undergo the process of meiosis.

The procedure that enables a young woman to freeze her eggs when she is single and save them for later use,up to age 50,is called ________.

A zygote contains 16 chromosomes.The diploid number of this cell is ________ [2n = ?].

The mitotic spindle guides the movement of chromosomes during certain stages of mitosis.

During the S phase,the cell

By the time a cell enters meiosis II,it has

Microtubules attach to plaques of protein on chromosomes; these plaques are called ________.

If a skin cell of an organism has 24 chromosomes,its gametes must also have 24 chromosomes.

Lily plants sometimes have twice as many chromosomes per cell as their parent plants.Which of the following statements explains how this phenomenon might have happened?

The successful union of one male gamete and one female gamete forms a new single cell known as a

The spindle microtubules break down and new nuclear envelopes form during the mitotic stage called ________.

During meiosis I,the microtubules from each spindle pole attach to only one member of a bivalent,generally the one closest to that spindle pole.

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Energy, Metabolism, and Enzymes

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Patterns of Inheritance

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From Gene to Protein

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How Evolution Works

The Origin of Species

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