Cell Cycle and Cell Division Questions — NEET Biology

Q1

If a diploid cell is treated with colchicine then it becomes

A triploid

B tetraploid

C diploid

D monoploid

Correct Answer

Option B

Solution

(b) Colchicine inhibits spindle formation causing doubling of chromosomes resulting in tetraploidy.

Q2

In S phase of the cell cycle:

A Amount of DNA doubles in each cell.

B Amount of DNA remains same in each cell.

C Chromosome number is increased.

D Amount of DNA is reduced to half in each cell.

Correct Answer

Option A

Solution

(a) During S or synthesis phase, replication of chromosomal DNA takes place. The amount of DNA per cell doubles.

Q3

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?

A G0 and G1

B G1 and S1

C Only G2

D G2 and M

Correct Answer

Option C

Solution

(c) Only G2 phase has 4C DNA content after replication is complete.

Q4

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

A same number of chromosomes but twice the amount of DNA

B twice the number of chromosomes and four times the amount of DNA

C four times the number of chromosomes and twice the amount of DNA

D twice the number of chromosomes and twice the amount of DNA

Correct Answer

Option B

Solution

(b) When S-phase completes, a somatic cell contains 2n chromosomes and 2C content of DNA.

Q5

DNA replication in bacteria occurs:

A Within the nucleolus

B Prior to fission

C Just before translation

D During S phase

Correct Answer

Option B

Solution

(b) In bacteria DNA replication occurs in cytoplasm prior to fission.

Q6

The correct sequence of phases of cell cycle is:

A M G1 G2 S

B G1 G2 S M

C S G1 G2 M

D G1 S G2 M

Correct Answer

Option D

Solution

(d) The correct sequence of phases of cell cycle is G1 S G2 M.

Q7

Cells in G0 phase :

A exit the cell cycle

B enter the cell cycle

C suspend the cell cycle

D terminate the cell cycle

Correct Answer

Option A

Solution

(a) G0 is a quiescent state where cells exist without dividing or preparing to divide.

Q8

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

A Reorganisation of all cell components takes place.

B Cell is metabolically active, grows but does not replicate its DNA.

C Nuclear Division takes place.

D DNA synthesis or replication takes place.

Correct Answer

Option B

Solution

(b) During G1 phase the cell is metabolically active and continuously grows but does not replicate its DNA.

Q9

Which one of the following structures will not be common to mitotic cells of higher plants?

A cell plate

B centriole

C centromere

D spindle fibres

Correct Answer

Option B

Solution

(b) Higher plants do not have centrioles.

Q10

A bacterium divides every 35 minutes. If a culture containing 10^5 cells per ml is grown for 175 minutes, what will be the cell concentration per ml?

A 5 x10^5 cells

B 35 x 10^5 cells

C 32 x 10^5 cells

D 175 x 10^5 cells

Correct Answer

Option C

Solution

(c) 175/35 = 5 divisions. Number of cells = 2^5 x 10^5 = 32 x 10^5.