Cell Cycle and Cell Division

Which stage of meiotic prophase shows terminalisation of chiasmata as its distinctive feature?

1. Pachytene
2. Leptotene
3. Zygotene
4. Diakinesis

The centriole undergoes duplication during :

1. G2 phase
2. S-phase
3. Prophase
4. Metaphase

Some dividing cells exit the cell cycle and enter vegetative inactive stage. This is called quiescent stage (G0). This process occurs at the end of

1. G1 phase
2. S phase
3. G2 phase
4. M phase

Match the following with respect to meiosis Select the correct option from the following

1. (A)-(iv), (B)-(iii), (C)-(ii), (D)-(i)
2. (A)-(iii), (B)-(iv), (C)-(i), (D)-(ii)
3. (A)-(i), (B)-(ii), (C)-(iv), (D)-(iii)
4. (A)-(ii), (B)-(iv), (C)-(iii), (D)-(i)

Dissolution of the synaptonemal complex occurs during

1. Diplotene
2. Zygotene
3. Pachytene
4. Leptotene

Identify the correct statement with regard to G1 phase (Gap 1) of interphase

1. Cell is metabolically active, grows but does not replicate its DNA.
2. DNA synthesis or replication takes place.
3. Nuclear Division takes place.
4. Reorganisation of all cell components takes place.

Cells in G0 phase:

1. suspend the cell cycle
2. terminate the cell cycle
3. exit the cell cycle
4. enter the cell cycle

The correct sequence of phases of cell cycle is:

1. S G1 G2 M
2. G1 S G2 M
3. M G1 G2 S
4. G1 G2 S M

The stage during which separation of the paired homologous chromosomes begins is

1. zygotene
2. pachytene
3. diplotene
4. diakinesis

Which of the following options gives the correct sequence of events during mitosis?

1. Condensation Nuclear membrane disassembly Arrangement at equator Centromere division Segregation Telophase
2. Condensation Crossing over Nuclear membrane disassembly Segregation Telophase
3. Condensation Arrangement at equator Centromere division Segregation Telophase
4. Condensation Nuclear membrane disassembly Crossing over Segregation Telophase

Anaphase Promoting Complex (APC) is a protein degradation machinery necessary for proper mitosis of animal cell. If APC is defective in a human cell, which of the following is expected to occur?

1. Chromosomes will be fragmented.
2. Chromosomes will not segregate.
3. Recombination of chromosome arms will occur.
4. Chromosomes will not condense.

Spindle fibres attach on to

1. centromere of the chromosome
2. kinetosome of the chromosome
3. telomere of the chromosome
4. kinetochore of the chromosome.

Which of the following is not a characteristic feature during mitosis in somatic cells?

1. Chromosome movement
2. Synapsis
3. Spindle fibres
4. Disappearance of nucleolus

In meiosis crossing over is initiated at

1. zygotene
2. diplotene
3. pachytene
4. leptotene.

During cell growth, DNA synthesis takes place on

1. S-phase
2. G1-phase
3. G2-phase
4. M phase

When cell has stalled DNA replication fork, which checkpoint should be predominantly activated?

1. G1/S
2. G2/M
3. M
4. Both G2/M and M

Match the stages of meiosis in column I to their characteristic features in column II and select the correct option using the codes given below.

1. (a)-(iii), (b)-(iv), (c)-(ii), (d)-(i)
2. (a)-(i), (b)-(iv), (c)-(ii), (d)-(iii)
3. (a)-(ii), (b)-(iv), (c)-(iii), (d)-(i)
4. (a)-(iv), (b)-(iii), (c)-(ii), (d)-(i)

Arrange the following events of meiosis in correct sequence (i) Crossing over (ii) Synapsis (iii) Terminalisation of chiasmata (iv) Disappearance of nucleolus

1. (i), (ii), (iii), (iv)
2. (ii), (iii), (iv), (i)
3. (ii), (i), (iv), (iii)
4. (ii), (i), (iii), (iv)

A somatic cell that has just completed the S phase of its cell cycle, as compared to gamete of the same species, has

1. twice the number of chromosomes and four times the amount of DNA
2. four times the number of chromosomes and twice the amount of DNA
3. twice the number of chromosomes and twice the amount of DNA
4. same number of chromosomes but twice the amount of DNA.

Select the correct option.

1. (A) - (i); (B) - (ii); (C) - (v); (D) - (iv)
2. (A) - (ii); (B) - (iii); (C) - (iv); (D) - (v)
3. (A) - (ii); (B) - (i); (C) - (iii); (D) - (iv)
4. (A) - (ii); (B) - (iii); (C) - (v); (D) - (iv)

During which phase(s) of cell cycle, amount of DNA in a cell remains at 4C level if the initial amount is denoted as 2C?

1. G0 and G1
2. G1 and S
3. Only G2
4. G2 and M

In 'S' phase of the cell cycle

1. amount of DNA doubles in each cell
2. amount of DNA remains same in each cell
3. chromosomes number is increased
4. amount of DNA is reduced to half in each cell.

The enzyme recombinase is required at which stage of meiosis?

1. Pachytene
2. Zygotene
3. Diplotene
4. Diakinesis

The complex formed by a pair of synapsed homologous chromosomes is called

1. bivalent
2. axoneme
3. equatorial plate
4. kinetochore.

A stage in cell division is shown in the figure. Select the answer which gives correct identification of the stage with its characteristics. [Figure]

1. Telophase Endoplasmic reticulum and nucleolus not reformed yet.
2. Telophase Nuclear envelope reforms, Golgi complex reforms.
3. Late anaphase Chromosomes move away from equatorial plate, Golgi complex not present.
4. Cytokinesis Cell plate formed, mitochondria distributed between two daughter cells.

During meiosis I, the chromosomes start pairing at

1. zygotene
2. pachytene
3. diplotene
4. leptotene.

During the metaphase stage of mitosis, spindle fibres attach to chromosomes at

1. kinetochore
2. both centromere and kinetochore
3. centromere, kinetochore and areas adjoining centromere
4. centromere.

A stage of mitosis is shown in the diagram. Which stage is it and what are its characteristics? [Figure]

1. Anaphase - Centromeres split and chromatids separate and start moving away.
2. Late prophase - Chromosomes move to spindle equator.
3. Metaphase - Spindle fibers attached to kinetochores, centromeres split and chromatids separate.
4. Metaphase - Chromosomes moved to spindle equator, chromosomes made up of two sister chromatids.

Identify the meiotic stage in which the homologous chromosomes separate while the sister chromatids remain associated at their centromeres.

1. Metaphase I
2. Metaphase II
3. Anaphase I
4. Anaphase II

During gamete formation, the enzyme recombinase participates during

1. metaphase I
2. anaphase II
3. prophase I
4. prophase II.