Cell Cycle and Cell Division

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.