Question 1

Which of the following statements about the microtubules that grow out from the centrosomes is true?
A) They pull the nuclear envelope apart.
B) They pull the centrosomes together.
C) They eventually become kinetochores.
D) They eventually attach to centromeres.

Accepted Answer

The microtubules that grow out from the centrosomes eventually attach to the centromeres, which are part of the duplicated chromosomes. They help in the separation of chromosomes during cell division. Option A is incorrect as it is the role of microtubules called spindle fibers to pull the nuclear envelope apart. Option B is incorrect as it is the role of contractile microfilaments to pull the centrosomes together. Option C is incorrect as kinetochores are structures that form on the centromeres and serve as attachment sites for microtubules during cell division.

Question 2

If a plant has a karyotype of 18 chromosomes,how many chromosomes would each of its gametes have?
A) 36
B) 18
C) nine
D) six

Accepted Answer

Gametes are formed through meiosis, which reduces the chromosome number by half. Therefore, if a plant has 18 chromosomes, each of its gametes would have 9 chromosomes.

Question 3

Which of the following things could NOT be determined from looking at a karyotype?
A) the gender of the individual who provided the sample
B) whether the source of the sample was a nonhuman species
C) whether the source of the sample was a somatic cell or a gamete
D) the height and eye color of the individual who provided the sample

Accepted Answer

Karyotypes only show the chromosomes of an individual, which can help identify genetic abnormalities and disorders but cannot determine physical traits such as height and eye color. The gender of the individual can be determined by looking at the sex chromosomes on the karyotype, and it can also be determined whether the sample was from a nonhuman species or a somatic cell or a gamete based on the number and arrangement of chromosomes.

Question 4

You are examining the rapidly dividing cells of an onion root tip and you see a cell whose chromosomes are visible and arranged in approximately the same shape and size as the nucleus.What stage of mitosis is this cell in?
A) metaphase
B) prophase
C) anaphase
D) telophase

Accepted Answer

During prophase, the chromosomes become visible and condense into structures that are the same shape and size as the nucleus, but they have not yet aligned at the cell's equator, which distinguishes this phase from metaphase.

Question 5

Chromosomes are lined up at the middle of the cell during the phase of cell division called
A) metaphase.
B) anaphase.
C) telophase.
D) interphase.

Accepted Answer

During metaphase of cell division, chromosomes are aligned at the equator of the cell, also known as the metaphase plate. In anaphase, the chromosomes are separated and pulled towards opposite poles of the cell. In telophase, the nuclear envelope reforms around the separated chromosomes. Interphase is the phase of the cell cycle where the cell is not dividing, and chromosomes are not lined up.

Question 6

At the completion of mitosis,the nucleus of a human somatic cell has ________ chromosomes.
A) 23
B) 46
C) 92
D) 184

Accepted Answer

During mitosis, the number of chromosomes remains the same. Before mitosis, a human somatic cell has 46 chromosomes, and after the completion of mitosis, each daughter cell also has 46 chromosomes. Therefore, the correct answer is B.

Question 7

The completion of the physical division of the parent cell cytoplasm that usually occurs during the last stage of mitosis is known as A) centrosome formation. B) G₀. C) cytokinesis. D) meiosis.

Accepted Answer

The completion of the physical division of the parent cell cytoplasm is known as cytokinesis. It typically occurs during the last stage of mitosis and is responsible for separating the two newly-formed daughter cells. Choices A, B, and D are not relevant to the process of cytokinesis.

Question 8

Gametes are produced by meiosis rather than mitosis because
A) mitosis would produce too many sister cells.
B) meiosis reduces the number of chromosomes so that the zygotes resulting from fertilization will have one full genome consisting of a diploid number of chromosomes.
C) meiosis doubles the number of chromosomes so that each gamete has twice the usual number of genes.
D) meiosis ensures that the gametes are identical to the cell that produced them.

Accepted Answer

Meiosis reduces the number of chromosomes so that the zygotes resulting from fertilization will have one full genome consisting of a diploid number of chromosomes. If gametes were produced through mitosis, the offspring resulting from the fusion of these gametes would have twice the number of chromosomes as their parent cells.

Question 9

The mitotic spindle is made of
A) centrosomes.
B) chromosomes.
C) kinetochores.
D) microtubules.

Accepted Answer

The mitotic spindle is made of microtubules, which are long protein filaments that radiate out from the centrosomes and attach to the chromosomes via kinetochores. While centrosomes are involved in organizing the microtubules, they themselves do not make up the spindle. Chromosomes are also involved in the spindle, but they do not make up the entirety of the structure.

Question 10

Plant cells perform cytokinesis differently than animal cells because
A) plant cytokinesis takes place during interphase,whereas animal cytokinesis takes place during cell division.
B) plant chromosomes are more difficult to separate than animal chromosomes.
C) the plant cell's rigid cell wall prevents the plasma membrane from pinching inward as it does in animal cells.
D) the centrosomes of plants do not replicate prior to cell division.

Accepted Answer

Plant cells have a rigid cell wall made up of cellulose that prevents the plasma membrane from pinching inward during cytokinesis as it does in animal cells. Instead, a cell plate forms between the two daughter nuclei, which eventually becomes the new cell wall separating the two daughter cells.

Question 11

An unduplicated chromosome contains
A) two sister chromatids.
B) a single molecule of double-stranded DNA combined with a large number of proteins.
C) the cell's karyotype.
D) its own spindle poles.

Accepted Answer

An unduplicated chromosome is a single molecule of double-stranded DNA combined with a large number of proteins. It has not been replicated yet, so it only contains one chromosome (not two sister chromatids). It also does not have spindle poles and is not a representation of the cell's karyotype.

Question 12

The successful union of one male gamete and one female gamete forms a new single cell known as a
A) histone.
B) zygote.
C) vesicle.
D) gametocyte.

Accepted Answer

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

Question 13

If a drug that inhibits the formation of microtubules is added to a culture of cells during the G₂phase,how would the cell division be affected? A) Cytokinesis would occur more rapidly. B) The nuclear envelope would be unable to break down. C) DNA synthesis would not occur. D) The spindle apparatus would be unable to form.

Accepted Answer

The formation of microtubules is crucial for the formation of the spindle apparatus, which is responsible for the separation of the duplicated chromosomes during mitosis. Therefore, if a drug inhibits the formation of microtubules, the spindle apparatus would be unable to form, and cell division would be affected. Specifically, the cell would be unable to proceed beyond the prophase of mitosis or might undergo abnormal division with incomplete separation of chromosomes.

Question 14

The two sister chromatids of a single chromosome are held together by a
A) centrosome.
B) spindle fiber.
C) centromere.
D) chromatin.

Accepted Answer

The two sister chromatids of a single chromosome are held together by a centromere.

Question 15

Which of the following foods is most likely to contain a haploid cell or cells?
A) a sirloin steak
B) an apple
C) one or more chicken eggs
D) a stalk of celery

Accepted Answer

Chicken eggs contain haploid germ cells, specifically the yolk and the egg white. The other options do not contain germ cells.

Question 16

In animals,only meiosis can lead to the production of new ________.
A) skin
B) brain
C) sperm
D) liver

Accepted Answer

Meiosis is the specialized cell division that leads to the formation of gametes, such as sperm and eggs, which are necessary for sexual reproduction and the formation of new individuals. Skin, brain, and liver cells are formed through the process of mitosis, which results in the production of identical copies of an original cell.

Question 17

You are examining the rapidly dividing cells of a fish embryo and notice a cell that seems to contain two nuclei with complete nuclear envelopes and decondensing chromosomes.The middle of the cell is pinched inward.This cell must be in
A) prophase.
B) telophase.
C) metaphase.
D) anaphase.

Accepted Answer

The presence of two nuclei with complete nuclear envelopes and decondensing chromosomes indicates that cell division has just completed. The pinching inward of the middle of the cell indicates that cytokinesis is occurring. Therefore, this cell must be in telophase.

Question 18

After a single cell undergoes meiosis in a male,how many sperm cells will be produced?
A) two
B) four
C) 12
D) 16

Accepted Answer

Meiosis in a male results in the production of four haploid cells, which later mature into sperm cells. Therefore, the correct answer is B) four.

Question 19

Which of the following statements about the chromosomes in a homologous pair is true?
A) They both came from the organism's mother.
B) They both came from the organism's father.
C) One chromosome came from the organism's mother and the other came from the organism's father.
D) Neither chromosome came from the organism's parents.

Accepted Answer

Homologous chromosomes are a pair of chromosomes that have the same genes in the same order, but may have different alleles. One chromosome in the pair is inherited from the organism's mother and the other from the organism's father. Thus, option C is the correct statement.

Question 20

During anaphase,daughter chromosomes do which of the following things?
A) They are condensed into chromatin.
B) They move toward opposite spindle poles.
C) They form homologous pairs.
D) They move toward the same spindle pole.

Accepted Answer

During anaphase, daughter chromosomes separate from each other and move toward opposite spindle poles. So, option B is the correct choice. Options A, C and D are incorrect as they do not reflect the events occurring during anaphase.

Quiz 7: Cell Division

Which of the following statements about the microtubules that grow out from the centrosomes is true?

If a plant has a karyotype of 18 chromosomes,how many chromosomes would each of its gametes have?

Which of the following things could NOT be determined from looking at a karyotype?

You are examining the rapidly dividing cells of an onion root tip and you see a cell whose chromosomes are visible and arranged in approximately the same shape and size as the nucleus.What stage of mitosis is this cell in?

Chromosomes are lined up at the middle of the cell during the phase of cell division called

At the completion of mitosis,the nucleus of a human somatic cell has ________ chromosomes.

The completion of the physical division of the parent cell cytoplasm that usually occurs during the last stage of mitosis is known as

Gametes are produced by meiosis rather than mitosis because

The mitotic spindle is made of

Plant cells perform cytokinesis differently than animal cells because

An unduplicated chromosome contains

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

If a drug that inhibits the formation of microtubules is added to a culture of cells during the G2 phase,how would the cell division be affected?

The two sister chromatids of a single chromosome are held together by a

Which of the following foods is most likely to contain a haploid cell or cells?

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

You are examining the rapidly dividing cells of a fish embryo and notice a cell that seems to contain two nuclei with complete nuclear envelopes and decondensing chromosomes.The middle of the cell is pinched inward.This cell must be in

After a single cell undergoes meiosis in a male,how many sperm cells will be produced?

Which of the following statements about the chromosomes in a homologous pair is true?

During anaphase,daughter chromosomes do which of the following things?

If a drug that inhibits the formation of microtubules is added to a culture of cells during the G₂phase,how would the cell division be affected?