Cell Cycle and Cell Division Test - 16

There are 4 phases of the cell cycle, namely G$$_1$$ phase, S phase, G$$_2$$ phase and M phase. During G$$_1$$ phase or gap 1 phase, the cell increases in size. Also, various proteins are synthesized in this phase. During S phase or synthesis phase, the DNA replication or duplication takes place. During G$$_2$$ phase, cell continues to grow until it enters the M phase or mitosis phase. Cell division takes place in M phase.

Meiosis is a specialized type of cell division that reduces the chromosome number by half( during Meiosis i ), creating four haploid cells ( during M I & M ii,) each genetically distinct from the parent cell that gave rise to them. So ,the correct option is B. ( Two nuclear divisions with chromosomes dividing once )

The cell division which reduces the half chromosomes of the parent cell is meiosis. Meiosis is a division that takes a diploid cell with two sets of chromosomes to a haploid cell one with a single set of chromosomes it means meiosis reduces the half number of chromosomes of the parent cell.

Spindle fibres are formed from microtubules which are composed of a protein named tubulin. These are helpful during cell division to separate the chromosomes at anaphase.
So, the correct answer is 'Tubulin'.

There are 4 phases of the cell cycle, namely G$$_1$$ phase, S phase, G$$_2$$ phase and M phase. During G$$_1$$ phase or gap 1 phase, the cell increases in size. Also, various proteins are synthesized in this phase. During S phase or synthesis phase, the DNA replication takes place. During G$$_2$$ phase, cell continues to grow until it enters the M phase or mitosis phase. Cell division takes place in M phase.

Gametogenesis is the process of formation of gametes, in higher organisms the cells are diploid that is containing two sets of chromosomes. The reproductive cells undergo meiotic division to produce haploid cells or gametes

The process of cell division by which most of the cells divide for growth is called mitosis. In this process, each cell called mother cell divides to form two identical daughter cells. The daughter cells have the same number of chromosomes as mother cell. It helps in growth and repair of tissues in organisms.
Hence the correct option is B.

• The division of cytoplasm is termed as cytokinesis. It happens in the final stage of mitosis which is a form of asexual cellular division.
• Mitosis has four different stages known as prophase, metaphase, anaphase, and telophase. Cytokinesis is a stage at which the cell furrow is being cut to form two identical daughter cells from the parent cell.
• Whereas, karyokinesis refers to the cell nucleus division during mitosis. It is usually followed by cytokinesis. Crossing over is a term used to refer to the exchange of genetic material between two homologous chromosomes.

So, the correct option is C

Correct option: B.
Explanation:

• It is given that the diploid chromosome number is 8 (2n).
• It contains 16 chromatids.
• Meiosis I starts with the diploid (2n) cells and ends with the haploid (n) daughter cells.
• Since, before meiosis I, the cell contains 16 (2n) chromatids, the number of chromatids in each daughter cell after meiosis I will be 8 (n).

• The cell cycle is comprised of a long interphase and a short division phase. The long interphase comprises of G$$_1$$ or first growth phase, S or synthetic phase, and G$$_2$$ or second growth phase. 
• Anaphase (represented by B) is the third phase of karyokinesis during mitosis.
  
• The process by which the nucleus of the parent cell divides into two daughter nuclei is known as karyokinesis (represented by A).
  
• The process by which the cytoplasm of the parent cell, divides into two daughter cells is cytokinesis and is represented by C in the question.
  
• In S phase, DNA of each chromosome replicates followed by the synthesis of histones. The phase marked D corresponds to the S phase of a typical cell cycle.

So, the correct answer is option C.