MCQ on Cell Cycle Phases

The cell division cycle, often known as the cell cycle, is a four-stage process in which two important molecular events occur: parent chromosomal duplication (which occurs in S phase) and equal chromosome detachment from the daughter cells (which occur during the M phase)

The cell cycle in eukaryotic cells is divided into two distinct phases: interphase and mitotic phase. While the cell grows and duplicates a DNA copy during interphase, the cell separates its DNA into two sets during the mitotic phase, resulting in the division of cytoplasm into two daughter cells.

Q1. Division of the Cytoplasm is considered as the

1. Mitosis
2. Cytokinesis
3. Synapsis
4. None of these

Ans. Cytokinesis is the right answer.

Cytokinesis is the process of cytoplasm division. It occurs at the final stage of mitosis, an asexual cellular division process.

Prophase, Anaphase, Metaphase and Telophase are the 4 stages of mitosis. The cell furrow is cut during cytokinesis, resulting in the formation of 2 similar daughter cells from parent cell.

Q2. Stage where chromosomes align on equator of spindle fiber is called

1. Telophase
2. Metaphase
3. Anaphase
4. Prophase

Ans. Metaphase is the correct answer.

The chromosomal spindle fibres constrict during anaphase, and daughter chromosomes travel to the opposite poles.

Chromosomes are positioned on equator of spindle threads during metaphase.

In prophase, chromosomes appear to be lengthy, with two chromatids spirally coiled around one another.

Chromosomes elongate and generate chromatin material during telophase.

Q3. The best stage at which the total number of chromosomes can be counted in any species is

1. Late Anaphase
2. Telophase
3. Late Prophase
4. Metaphase

Ans. Metaphase is the correct answer.

Metaphase is the ideal stage for determining the total chromosome number in every species and conducting a detailed study of chromosome shape. Most morphological investigations use mitotic metaphase chromosomes because mitotic cells are easy to obtain by. At this point, the centrioles are located at the cell’s opposite poles.

Q4. Which of the following is the best stage of cell division to determine the size, shape and number of chromosomes?

1. Telophase
2. Metaphase
3. Interphase
4. Prophase

Ans. Metaphase is the correct answer.

Metaphase is the finest cell division stage for observing the form, size, and number of chromosomes. During this phase, the chromosomes are the shortest and thickest, and they are positioned at the equator to form an apparent plate known as the equatorial or metaphase plate, which is easily visible. As a result, karyotyping and chromosomal analysis are frequently performed during this phase.

Q5. In which of the following the Balbiani rings are found?

1. Heterosome
2. Autosome
3. Polytene Chromosome
4. None of the above

Ans. Polytene Chromosome is the correct answer.

Polytene chromosomes are generated in Drosophila salivary glands as a result of chromosome replication and homologous synapsis without cell division. Balbiani rings are larger polytene chromosomes that appear between 2 bands in the staining process.

Q6. Which of the following structures always vanish during mitosis and meiosis?

1. Plasma Membrane
2. Plastids
3. Nucleolus & Nuclear Membrane
4. None of these

Ans. Nucleolus and Nuclear Membrane is the correct answer.

During mitosis and meiosis, the nucleolus & nuclear membrane are always lost. During the beginning of mitosis, the nucleolus vanishes, the chromosomes compress, and the nuclear membrane breaks down, allowing the most of the nucleus’ contents to escape into the cytoplasm. The procedure is reversed at the end of mitosis.

Q7. Duplication of Centrosomes takes place in which of the following phase?

1. S phase
2. G0 Phase
3. G1 Phase
4. None of these

Ans. S phase is the correct answer.

In the Eukaryotic Cell, the centrosome is the main microtubule-organizing centre (MTOC).The pericentriolar material is made up of two centrioles that are encompassed by an electron – dense matrix (PCM).The centrosome can anchor, nucleate, and release microtubules, which is necessary for it to organise microtubule arrays like the mitotic spindle. During S phase (stands for synthesis phase) of cell cycle, centrosomes are duplicated in dividing cells.

Q8. Which of the following checkpoint is considered a restriction point?

1. M Checkpoint
2. G1 Checkpoint
3. G2 Checkpoint
4. None of the above

Ans. G1 Checkpoint is the correct answer.

 The G1 checkpoint, also considered as the restriction point in the mammalian cells and start point in the yeast, marks the beginning of the cell cycle. With the cell’s progression through G1, it can either postpone G1, enter a quiescent state known as G0, or advance through restriction point, depending on external and internal factors.

Q9. The characteristic of which of the following stages of mitosis is the separation of sister chromatids?

1. Metaphase
2. Telophase
3. Anaphase
4. None of these

Ans. Anaphase is the correct answer. 

Anaphase is the 4th phase of mitosis. Anaphase is the process by which a parent cell’s replicated genetic material is separated into 2 identical daughter cells from the nucleus. Anaphase guarantees that each daughter cell has the same set of chromosomes, and is followed by telophase, the 5th and final phase of mitosis.

Q10.  During which of the following stages of mitosis the individual chromosomes become distinct through the light microscope?

1. Telophase
2. Anaphase
3. Prophase
4. Prometaphase

Ans. Prophase is the correct answer.

Definition of Prophase In eukaryotes, prophase is the first phase of cell division. Prophase is marked by condensing of the chromosomes and separation of centrioles in centrosome in both mitosis and meiosis. Each centriole is half of the organelle, which controls microtubules in the cell.

During the prophase stage of mitosis the individual chromosomes become distinct through the light microscope.