Question 1

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. The zygote contains the genetic material from both parents and develops into a new individual.

A) Histones are proteins that help organize and package DNA in eukaryotic cells.
C) A vesicle is a small fluid-filled sac within a cell that stores and transports cellular products.
D) A gametocyte is a cell that divides to produce gametes during sexual reproduction.

Question 2

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

The answer of An unduplicated chromosome contains
A) two sister chromatids.
B)...

Question 3

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 haploid cells, meaning they contain half the number of chromosomes as the diploid parent cell. If the plant has a karyotype of 18 chromosomes, each gamete would have 9 chromosomes.

Question 4

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?
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

Microtubules are essential for the formation of the spindle apparatus, which is necessary for chromosome alignment and segregation during cell division. If a drug that inhibits the formation of microtubules is added during the G₂ phase, the spindle apparatus would be unable to form, leading to a failure in chromosome segregation and cytokinesis. Therefore, the correct answer is D, the spindle apparatus would be unable to form.

Question 5

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

Accepted Answer

A human somatic cell has 46 chromosomes (23 pairs) at the completion of mitosis. During mitosis, the cell duplicates its DNA and divides its chromosomes equally between two daughter nuclei, resulting in each daughter nucleus containing the same number of chromosomes as the parent cell.

Question 6

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 of the chromosomes during mitosis. This attachment is essential for proper chromosome segregation and the formation of the spindle fibers that pull the sister chromatids apart. Option A is incorrect because microtubules do not directly pull apart the nuclear envelope. Option B is incorrect because the centrosomes are already separated at the beginning of mitosis and the microtubules do not pull them together. Option C is incorrect because kinetochores are protein structures that form at the centromeres, not from the microtubules themselves.

Question 7

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

The answer of You are examining the rapidly dividing cells...

Question 8

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 centromere is the specialized region of a chromosome where the two sister chromatids are held together. This attachment allows for proper separation of the sister chromatids during cell division.

Option A (centrosome) is incorrect because it is an organelle that helps in cell division by organizing the microtubules, but it is not directly involved in holding sister chromatids together.

Option B (spindle fiber) is incorrect because spindle fibers are responsible for separating the sister chromatids during cell division and are attached to the kinetochores located at the centromere.

Option D (chromatin) is incorrect because chromatin is the complex of DNA and proteins that makes up chromosomes, but it does not directly hold the sister chromatids together.

Question 9

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 suggests that the cell is completing mitosis. The decondensing chromosomes and the pinched middle of the cell indicate that cytokinesis is occurring. Since the cell has completed division and is returning to a nondividing state, it must be in telophase.

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 that prevents the plasma membrane from pinching inward during cytokinesis as animal cells do. Instead, a cell plate forms between the two daughter nuclei, which eventually becomes a new cell wall dividing the two daughter cells.

Question 11

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

Accepted Answer

The mitotic spindle is made up of microtubules, which are protein filaments that are responsible for separating the chromosomes during cell division. While centrosomes are important for organizing the microtubules, they are not a component of the spindle itself. Chromosomes and kinetochores are also involved in spindle function, but they are not part of the spindle structure.

Question 12

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

After meiosis in a male, a single cell will produce four sperm cells.

Question 13

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 pairs of chromosomes are matched pairs of chromosomes that are similar in size, shape, and gene content. One chromosome in the pair comes from the organism's mother and the other comes from the organism's father. Therefore, option C is the correct choice.

Question 14

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 in a cell by half, creating four genetically diverse haploid cells (gametes) from one parent cell. This is important for sexual reproduction because when two haploid gametes unite during fertilization, they create a diploid zygote with a full set of chromosomes, half from each parent.

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

One or more chicken eggs are most likely to contain a haploid cell as they are reproductive cells. The other options are not likely to contain haploid cells.

Question 16

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

Cytokinesis is the completion of the physical division of the parent cell cytoplasm, which occurs during the last stage of mitosis. Choice A, centrosome formation, is a process that occurs during prophase of mitosis. Choice B, G0, refers to a non-dividing phase in the cell cycle. Choice D, meiosis, is a different type of cell division that results in the formation of gametes with half the number of chromosomes as the parent cell.

Question 17

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, chromosomes align at the equator of the cell, also known as the metaphase plate. This alignment is essential for proper chromosome separation during anaphase. In contrast, during anaphase, the chromosomes are pulled apart towards opposite poles of the cell, and during telophase, the cell completes the separation of the two sets of chromosomes into two distinct nuclei. Interphase is not a phase of cell division, but rather the period of the cell cycle between two successive cell divisions.

Question 18

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

Karyotype only shows the number and structure of chromosomes, which can provide information about genetic disorders and anomalies. Physical characteristics such as height and eye color are determined by many genes, including those on chromosomes but cannot be determined solely from a karyotype.

Question 19

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 produces gametes (sperm and egg cells) in animals. Skin, brain, and liver cells are not produced by meiosis, but rather by mitosis or differentiation from stem cells.

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, sister chromatids are separated and pulled apart by the spindle fibers toward the opposite poles of the cell. This results in the formation of two distinct sets of daughter chromosomes as they move away from each other to opposite cell poles, preparing for the next stage of mitosis. Options A, C, and D do not accurately describe the events occurring during anaphase.

Quiz 7: Cell Division

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

An unduplicated chromosome contains

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

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?

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

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

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?

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

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

Plant cells perform cytokinesis differently than animal cells because

The mitotic spindle is made of

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?

Gametes are produced by meiosis rather than mitosis because

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

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

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

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

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

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