Biology

Cell Cycle and Chromosomes

1,348 Questions

Explore a curated list of questions covering the cell cycle, mitosis, and meiosis. Topics include DNA replication, chromosomal structures, and genetic disorders. This material is essential for students preparing for biology and general science competitive exams.

Cell cycle eventsDNA replicationMeiosis processChromosomal structuresGenetic disorders

Cell Cycle and Chromosomes Questions

Multiple choice

Double minute chromatin bodies are indicative of

  1. translocation

  2. inactivation of a tumor suppressor gene

  3. apoptosis

  4. gene amplification
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Double minute chromatin bodies are indicative of gene amplification, one of the mechanisms of oncogene activation.

Multiple choice

When a splitting cell is treated with the hydrogen peroxide, its spindle fibers precipitate because of disulphide bridges formation. Such reaction denotes that spindle fiber and microtubules are_____________.

  1. non-polar organic structures

  2. glycosyl structures

  3. proteinaceous structures

  4. none of the above
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

When a splitting cell is treated with the hydrogen peroxide its spindle fibers precipitate because of disulphide bridges formation. Such reaction denotes that spindle fiber and microtubules are proteinaceous structures.

Multiple choice

Mitotic cell cycle is categorised usually into 4 phases- G1, S, G2 and M. Considering mitotic cycle time of 18 hours, distribution of time period (in hours) for every phase will be___________.

  1. G1 - 1, S - 3, G2 - 5, M - 9

  2. G1 - 9, S - 1, G2 - 3, M - 5

  3. G1 - 9, S - 5, G2 - 3, M - 1

  4. G1 - 3, S - 5, G2 - 9, M - 1
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

In mitotic cell division, a cell that previously replicated each of its chromosomes isolates the chromosome in its nuclei into 2 similar chromosome sets where each set in its own nucleus. Distribution of time period (in hours) for every phase will be 3, 5, 9 and 1.

Multiple choice

Cell division is, where a parent cell is divided into 2 or more daughter cells. Typically, cell division occurs as part of larger cell cycle. In eukaryotes, it is of 2 types: vegetative (daughter cell is similar to parent cell) & reductive (chromosome number in daughter cell is decreased by half for producing haploid gametes) cell division. Prokaryotes also possess vegetative cell division termed as binary fission.

The mitosis promoting factor (MPF) that propels the animal cell into division stage has 2 important sun units: 1 is catalytic & other is regulatory. Which of following is regulatory sub unit of MPF?

  1. Ubiquitin

  2. Cyclin

  3. Cdk (Cyclin dependent kinase)

  4. Proline
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The mitosis promoting factor (MPF) that propels the animal cell into division stage has 2 important sun units: 1 is catalytic & other is regulatory. Cdk (Cyclin dependent kinase) is a protein kinase family which regulates cell cycle. It also regulates transcription, processing of mRNA & differentiation of nerve cells.  

Multiple choice

Cell division is where a parent cell is divided into 2 or more daughter cells. Typically cell division occurs as part of larger cell cycle. In eukaryotes, it is of 2 types: vegetative (daughter cell is similar to parent cell) & reductive (chromosome number in daughter cell is decreased by half for producing haploid gametes) cell division. Prokaryotes also possess vegetative cell division termed as binary fission.

Colchine arrests either mitotically dividing cell at metaphase by__________.

  1. dislodging chromosomes from fibrous elements of spindle and consequently the chromosome remain confined to equatorial plane

  2. preventing movement of spindle fibers as the result of which chromosomes fail to go to opposite poles

  3. preventing polymerisation of tubulin into microtubules of spindle

  4. destroying contractile property of spindle protein which ultimately coagulates
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Colchine arrests either mitotically dividing cell at metaphase by preventing polymerisation of tubulin into microtubules of spindle.

Multiple choice

In the nucleus of each cell, each chromosome is made up of

  1. DNA and histone

  2. RNA and histone

  3. DNA and glycoprotein

  4. RNA and glycoprotein

  5. None of these
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Yes, it is correct. Each chromosome is made up of DNA. It is tightly coiled many times around proteins and histones, which support its structure.

Multiple choice

The number of chromosomes in human sperms is

  1. 46

  2. 23

  3. 21

  4. 42
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Human sperm cells contain 23 chromosomes (haploid number), which is half the 46 chromosomes found in somatic cells. This ensures that when sperm fertilizes an egg (also 23 chromosomes), the resulting zygote has the normal diploid number of 46.

Multiple choice

Which of the following characterises the sexual development of the fetus?

  1. The sex of the developing embryo is determined by a single gene present on the Y chromosome.

  2. In the absence of a Y chromosome, the sexual development of the developing embryo will fail to follow any pattern.

  3. The maturation of the fetal gonads into the female type are initiated in the presence of estrogens.

  4. The sex of the developing embryo is determined by the set of genes on the Y chromosome.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

A single gene on the Y, called SRY, triggers testes development in the early embryo and once these begin to form, the rest of the embryo also becomes male. Thus, the sex of the developing embryo is determined by a single gene present on the Y chromosome.