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

The kind of cell division that reduces the chromosome number by half and results in the production of haploid daughter cells is called meiosis. Which of the following is not a characteristic of meiosis?

  1. At the end of meiosis 2, three haploid cells are formed.

  2. It ensures the production of haploid phase in the life cycle of sexually reproducing organisms.

  3. It involves 2 sequential cycles of nuclear and cell division.

  4. Meiosis 1 is initiated after the parental chromosomes have replicated to produce identical sister chromatids at the S phase.

  5. It involves pairing of homologous chromosomes.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

This is the correct option as this is not a characteristic of meiosis. At the end of meiosis 2, four haploid cells are formed.

Multiple choice

Which of the following statements is/are false?

a. Prophase of the mitosis division is longer and more complex than the prophase of first meiotic. b. Mitosis accomplishes the segregation of duplicated chromosomes into daughter nuclei. c. During cytoplasmic division, mitochondria and plastids get distributed between the two daughter cells.

  1. Only a

  2. Only a and b

  3. Only b

  4. Only b and c

  5. Only c
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

This is the correct option as this statement is false. Prophase of the first meiotic division is longer and more complex than the prophase of mitosis.

Multiple choice

Match the following:

 
a. Anaphase 2 1. In this stage, the chromosomes again become compact and by the end of this stage, the nuclear membrane disappears.
b. Metaphase 2 2. In this stage, the chromosomes align at the equator.
c. Prophase 2 3. This stage begins with the simultaneous splitting of the centromere of each chromosome.

  1. a - 1, b - 2, c - 3

  2. a - 1, b - 3, c - 2

  3. a - 2, b - 3, c - 1

  4. a - 3, b - 2, c - 1

  5. a - 3, b - 1, c - 2
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

This is the correct option. Anaphase 2 stage begins with the simultaneous splitting of the centromere of each chromosome. In metaphase 2, the chromosomes align at the equator. In prophase 2, the chromosomes again become compact and by the end of this stage, the nuclear membrane disappears.

Multiple choice

Match the following:

 
a. Gap 1 phase 1. In this phase, DNA replication begins in the nucleus and the centriole duplicates in the cytoplasm.
b. Synthesis phase 2. In this phase, cell growth continues and proteins are synthesised in preparation for mitosis.
c. Gap 2 phase 3. In this phase, the cell is metabolically active and grows continuously, but does not replicate its DNA.

  1. a - 3, b - 2, c - 1

  2. a - 1, b - 3, c - 2

  3. a - 3, b - 1, c - 2

  4. a - 2, b - 1, c - 3

  5. a - 1, b - 2, c - 3
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

This is the correct option. In gap 1 phase, the cell is metabolically active and grows continuously, but does not replicate its DNA. In synthesis phase, DNA replication begins in the nucleus and the centriole duplicates in the cytoplasm. In gap 2 phase, cell growth continues and proteins are synthesised in preparation for mitosis.

Multiple choice

Match the following:

a. Leptotene stage 1. During this stage, chromosomes start pairing together and this process is called synapsis.
b. Zygotene stage 2. During this stage, under a light microscope, chromosomes become gradually visible.
c. Pachytene stage 3. During this stage, bivalent chromosomes clearly appear as tetrads.

  1. a - 3, b - 1, c - 2

  2. a - 2, b - 1, c - 3

  3. a - 1, b - 2, c - 3

  4. a - 1, b - 3, c - 2

  5. a - 2, b - 3, c - 1
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

This is the correct option. During leptotene stage, under a light microscope, chromosomes become gradually visible. During zygotene stage, chromosomes start pairing together and this process is called synapsis. During pachytene stage, bivalent chromosomes clearly appear as tetrads.

Multiple choice

Determine the correctness or otherwise of the following Assertion (a) and the Reason (r) Assertion: In synchronous culture, majority of the cells move to next phase of the cell cycle simultaneously. Reason: Synchronous culture could be obtained by starving cells for essential nutrient components.

  1. both (a) and (r) are true and (r) is the correct reason for (a)

  2. both (a) and (r) are true but (r) is not the correct reason for (a)

  3. (a) is true but (r) is false

  4. (a) is false but (r) is true
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Synchronous cultures are indeed characterized by cells moving through the cell cycle phases simultaneously, which is the definition of synchrony. Starving cells for essential nutrients is a valid method to obtain synchronous culture - when nutrients are restored, all cells resume division at the same time. Therefore, the reason correctly explains why the assertion is true.

Multiple choice

Paraspeckle, a sub-nuclear body, is absent during

  1. telophase

  2. interphase

  3. metaphase

  4. anaphase
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

During telophase, when the two daughter nuclei are formed, there is no RNA Pol II transcription. So, the protein components like paraspeckles instead form a perinucleolar cap. Thus, they are absent in telophase.

Multiple choice

The characteristic feature of meiosis is that

  1. daughter cells have the same genetic information as the parent cell

  2. centromere are divided at anaphase II

  3. homologous chromosomes do not cross-over

  4. daughter cells have half the number of chromosomes of the parent cell (2n - n)
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Meiosis is a type of cell division that reduces the number of chromosomes in the parent cell by half and produces four gamete cells.

Multiple choice

Among the given list of mutations, which type of mutation is polyploidy?

  1. Germline mutation

  2. Somatic mutation

  3. Frameshift mutation

  4. Chromosomal mutation

  5. Point mutation
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Chromosomal mutation is involving the change in chromosome structure. The changes in structure will change the composition or location allele. Polyploidy is an example of chromosomal mutation. Polyploidy is a condition wherein organisms have three or more sets of genetic variation (3n or more).