Deck 8: Cell Division

Question 1

Animal and plant cells are usually

A) diploid.
B) haploid.
C) triploid.
D) homologous.
E) reproductive.

Answer 1

diploid.

Question 2

In sexual reproduction of eukaryotes

A) the gametes are usually diploid.
B) the zygotes are usually haploid.
C) fusion occurs immediately after meiosis.
D) the egg and sperm are produced by mitosis.
E) meiosis halves the number of chromosomes.

Answer 2

meiosis halves the number of chromosomes.

Question 3

DNA in a prokaryotic cell is

A) a linear structure.
B) moved around the cell by spindle fibres.
C) composed of a single, circular molecule.
D) attached to the nuclear membrane.
E) condenses to form a visible structure during binary fission.

Answer 3

composed of a single, circular molecule.

Question 4

Which of the following statements about prokaryote cell replication is CORRECT?

A) The newly forming cell wall and cell membrane grow outwards from the middle of the cell.
B) The circular DNA molecule is unattached to the plasma membrane before and after replication.
C) The circular DNA molecule is single stranded before it replicates.
D) The two replicated DNA molecules are separated by the growth of the plasma membrane and cell wall between them.
E) The newly replicated DNA is attached to the plasma membrane on opposite side of the cell.

Question 5

In eukaryote cells, the amount of DNA in a cell doubles during the

A) S phase of the cell cycle.
B) G₁ phase of the cell cycle.
C) M phase of the cell cycle.
D) G₂ phase of the cell cycle.
E) G₀ phase of the cell cycle.

Question 6

If a cell ceases to divide during the cell cycle, it exits during _______ and enters a state called ______. Fill in the blanks to complete this statement.

A) G₁, S
B) G_1, G₂
C) S, G₁
D) G₁, G₀
E) G_0, M

Question 7

Very specialised cells such as nerve cells no longer undergo division. In what stage of the cell cycle are these cells?

A) G₁ phase
B) S phase
C) G₂ phase
D) Mitosis
E) G₀ phase

Question 8

After S phase and before mitosis, a chromosome consists of two chromatids

A) held together at the centromere.
B) each containing one long molecule of DNA.
C) which are genetically identical.
D) in an enlarged nucleus.
E) All of the statements are true.

Question 9

In animal cells, the centrosomes

A) are formed during prophase.
B) separate during prophase.
C) contain two centrioles.
D) are a protein disc for attachment of microtubules.
E) attach to the centromeres.

Question 10

An important feature of prophase of mitosis is

A) crossing over between homologous chromosomes.
B) the pairing up of chromosomes.
C) the exchange of genetic material.
D) the condensation of chromosomes.
E) the breakdown of the nuclear membrane.

Question 11

The mitotic spindle attaches to the centromere by inserting its microtubules in the

A) kinetochore.
B) equatorial plate.
C) synaptonemal complex.
D) centrosome.
E) asters.

Question 12

In animal cells undergoing mitosis, division of the cytoplasm is caused by a contracting ring of

A) interphase microtubules.
B) kinetochore fibres.
C) actin filaments.
D) tubulin filaments.
E) midbody fibres.

Question 13

During mitosis in a plant cell, the poles are broad and the spindle barrel-shaped because plant

A) chromosomes do not have kinetochores.
B) cells do not have an aster.
C) microtubules are made of actin.
D) microtubule assemble is not as strong as in animal cells.
E) cells do not have centrioles.

Question 14

Phragmoplasts are

A) only found in animal cells.
B) made up of contracting actin filaments.
C) fibrous structures located at the position of a developing cell wall.
D) membrane-bound organelles.
E) microtubules which form on the cell wall to join the cell plate.

Question 15

Which of the following provides evidence to show cytokinesis is independent of mitosis?

A) Cytokinesis does not begin until anaphase.
B) Anti-microtubule drugs applied to dividing cells inhibit chromosome separation but not cytokinesis.
C) A phragmoplast forms in plants but not in animals.
D) Cytokinesis is dependent on the formation of the midbody and mitosis is not.
E) In meiosis, there are two separate cell divisions, not one.

Question 16

In plant cells, the position at which the new cell wall will form is indicated by

A) the point at which the circular chromosome is attached to the plasma membrane.
B) a point equidistant between the poles of the aster.
C) a point at the middle of the cell.
D) a band of microtubules near the cell wall before prophase commences.
E) the position of the centriole in the cell.

Question 17

A diploid cell with a total of sixteen chromosomes undergoes mitosis. This type of division would result in which of the following?

A) Four genetically identical cells.
B) Two cells each with eight chromosomes.
C) Two cells each with sixteen chromosomes.
D) Two cells which are genetically different.
E) Four genetically different cells.

Question 18

In animal cells, a drug that disrupts actin-based activity in the cell would be expected to prevent

A) cytokinesis.
B) DNA replication.
C) formation of the mitotic spindle fibres.
D) condensation of the chromosomes.
E) movement of the chromosomes.

Question 19

If a drug which prevents the disassembly of microtubules is added to cells early in cell division it would be expected to disrupt

A) cytokinesis.
B) DNA replication.
C) condensation of the chromosomes.
D) formation of the mitotic spindle fibres.
E) movement of the chromosomes.

Question 20

During which phase does the S-phase-promoting factor activate proteins?

A) S
B) G₂
C) G₁
D) G₀
E) M

Question 21

In the cell cycle

A) DNA replicates at M phase.
B) chromosomes become visible under the light microscope at G₁ phase.
C) differentiated cells exit the cell cycle at S phase.
D) important check points control cell cycle progression.
E) cytochalasins, which act as anti-actin drugs, prevent progression of the cell cycle.

Question 22

All of the following are characteristics of cancer cells, EXCEPT

A) absolute numbers of chromosomes.
B) chromosomal abnormalities.
C) normal cell cycle progression.
D) loss of check point controls.
E) loss of response to cell growth signals.

Question 23

Meiosis produces four cells that are

A) haploid and genetically identical to each other.
B) haploid and genetically identical to the parent cell.
C) haploid and genetically different from each other.
D) diploid and genetically different from each other.
E) diploid and genetically different from the parent cell.

Question 24

There a number of differences between anaphase of mitosis and anaphase I of meiosis. The following feature is only found in anaphase of mitosis.

A) Centromeres split.
B) Homologous chromosomes separate from their partners.
C) Spindle fibres shorten.
D) Chromosomes line up at the equator of the cell.
E) Chromatids are held together by the kinetichore.

Question 25

Chromatids of homologous chromosomes may exchange genetic material

A) during prophase of mitosis.
B) during metaphase of meiosis I.
C) during interphase.
D) during prophase I of meiosis.
E) between meiosis I and meiosis II.

Question 26

Chromosomes consist of a single chromatid during

A) prophase of mitosis.
B) metaphase of mitosis.
C) anaphase I of meiosis.
D) anaphase II of meiosis.
E) metaphase I of meiosis.

Question 27

The vinegar fly, Drosophila, has eight chromosomes in normal body cells. At prophase II of meiosis the nucleus will have

A) four chromosomes, each with two chromatids.
B) four chromosomes, each with one chromatid.
C) eight chromosomes, each with two chromatids.
D) eight chromosomes, each with one chromatid.
E) eight chromosomes each with four chromatids.

Question 28

Meiosis and mitosis have a number of features in common. However, only meiosis has the following feature.

A) The presence of chromatids.
B) The pairing-up of homologous chromosomes.
C) The movement of chromosomes to the poles of the cell.
D) The condensation of chromosomes.
E) The separation of sister kinetochores and rapid movement to the poles of the cell.

Question 29

The two identical copies of chromosomes produced in a cell during DNA synthesis are called

A) chromatids.
B) sister chromatids.
C) sister chromosomes.
D) homologous chromosomes.
E) homologous chromatids.

Question 30

Interphase is composed of

A) G₂ +M.
B) G₁ + S + G₂.
C) prophase + prometaphase + metaphase + anaphase.
D) cytokinesis + mitosis.
E) meiosis I + meiosis II.

Question 31

In cell division, the 'Start' point defines the point at which the cell commits to progression through the cell cycle. Which of the following are true about the Start point?

A) It occurs at the beginning of S phase when DNA synthesis commences.
B) It is the point in the cell cycle when the MPF complex accumulates.
C) It is the point in anaphase when the sister chromatids separate from each other.
D) It signals the commencement of Meiosis II.
E) It is the point when a cyclin-dependent kinase binds to a cyclin and the complex activates genes required for DNA synthesis.

Question 32

An organism has 24 chromosomes. After meiosis II, but before cytokinesis, how many chromosomes will each cell have?

A) 6
B) 12
C) 24
D) 36
E) 48

Question 33

Checkpoint controls in cell division

A) are important during G₂ to inhibit the MPF activity and prevent entry into M phase.
B) are essential for ensuring the DNA integrity of replication.
C) involve the activation of cyclin-dependent kinases by binding to cyclin.
D) are points in cell division where specific proteins are phosphorylated.
E) All of these statements about checkpoint controls are correct.

Question 34

In prokaryotes, what is the process mediated by the ftsZ proteins during cell division?

A) only eukaryotes carry the genes that encode for the ftsZ proteins.
B) cell wall 'softening' so it can expand and extend across two cells.
C) the growth of the cell wall and membrane across the middle of the cell.
D) the formation of a ring of microfilaments perpendicular to the point of cell division.
E) chromosomal duplication.

Question 35

Which of the following is INCORRECT in relation to the G₁ cell cycle phase

A) It is also known as the first gap phase.
B) It is the longest part of the cell cycle.
C) It is the first part of interphase.
D) It immediately follows the completion of mitosis.
E) It is the period in which DNA is replicated.

Question 36

Following fertilisation, what is the name of the process that generates somatic cells that make up a developing embryo?

A) Mitosis
B) Binary fission
C) Meiosis
D) Homologous recombination
E) Cellular demarcation

Question 37

If identical sister chromatids are held together as one chromosome in a cell, what would be the ploidy number of that cell and why?

A) The cell can be either haploid (1n) or diploid (2n) depending on the stage of the cell cycle.
B) Haploid (1n) because it still has the same number of homologous pairs of chromosomes.
C) Diploid (2n) because it still has the same number of homologous pairs of chromosomes.
D) Diploid (2n) because the number of chromosomal arms has increased.
E) Haploid (1n) because the cell is about to divide and the chromatids separate to form the genetic blueprint for each individual cell.

Question 38

Reduction division is unique to

A) the second meiotic division.
B) the first meiotic division.
C) mitosis.
D) interphase.
E) cell cycle stages G₁ and G₂.

Question 39

What is the result when homologous chromosomes are randomly segregated, combined with crossing-over events?

A) Mitosis
B) New combinations of parental genes
C) All options listed here are correct
D) Generation of haploid cells
E) Sexual reproduction

Question 40

During anaphase

A) a chiasma is formed.
B) the plasma membrane folds inwards.
C) DNA is replicated.
D) homologous chromosomes separate and move to opposite poles.
E) sister chromatids separate and move to opposite poles.

Question 41

Two scientists are discussing mitosis in plant cells. Scientist one states that plant cells undergo cleavage in a manner similar to animal cells, whilst scientist two other argues that instead they form a cell plate. Which scientist is correct and why?

A) Scientist one, as all eukaryotic cells undergo mitosis in an essentially identical manner.
B) Scientist two, as animal cells do not undergo cleavage because of their cell wall.
C) Scientist one, as even though there are some distinct differences in the process of mitosis in animal and plant cells, cleavage is shared by both.
D) Scientist two, but the context given for the cell plate is irrelevant to mitosis.
E) Both scientists are incorrect; plant cells divide by the action of vesicles deposited by the tonoplast.

Question 42

Which of the following statements in relation to cytokinesis is INCORRECT?

A) Cytokinesis begins late in mitosis.
B) Cytokinesis can involve pinching of the cytoplasmic membrane.
C) Cytokinesis obligatorily includes the deposition of a new membrane between separated chromosomes.
D) Cytokinesis and mitosis are separable events.
E) The creation of new cells is dependent on cytokinesis.