The Differences Between Mitosis And Meiosis

The Differences Between Mitosis And Meiosis

Question 1. Describe the meiosis in brief without giving its stages.
Answer.

The meiosis is a special type of cell division that occurs only in germ cells. By meiotic division, the diploid germ cell gives rise to four haploid gametes. Meiosis involves two successive cell divisions: meiosis 1 and meiosis 2.

Before meiosis, the DNA (2N) replicates to form double the amount of DNA (4N), but the chromosome number remains diploid (2N).

Meiosis 1: During meiosis I, the DNA is reduced to a diploid (2N) amount but chromosome number is halved to haploid value (1N).

1. Meiosis 1 is reductional division and heterotypical.
2. Meiosis 2 During meiosis 2, the amount of DNA is reduced to haploid but the chromosome number remains haploid.

Meiosis 2: Meiosis 2 is similar to mitosis and homotypical. This means that when the ovum is fertilized with spermatozoon, the resultant zygote has 46 chromosomes called a diploid number. Thus, the child has some characteristics inherited from the mother and some from the father.

Question 2. Enumerate the differences between mitosis and meiosis.
Answer.

The differences between mitosis and meiosis are given in Table.

Differences Between Mitosis and Meiosis

 

The Stages Of Mitosis And Cell Division

Question 1. Write a short note on mitosis.
Answer.

The mitosis is the most common type of cell division and occurs in almost all somatic cells. It results in two genetically identical cells.

Mitosis Features

• In this type of cell division, the diploid parent cell gives rise to two identical diploid daughter cells. The daughter cells also receive an equal amount of cytoplasm.
• In this type of cell division, DNA replication occurs before cell division, thus doubling the amount of DNA (46, 4N) and yielding double-stranded chromosomes.
• During mitosis, 23 pairs of chromosomes replicate. The two identical sets of chromosomes move to the opposite poles of the parent cell, which then divides into two daughter cells. Each daughter cell receives a set of 23 pairs of chromosomes (diploid number), i.e. 46, 2N.

Question 2. What are the various stages of mitotic cell division?
Answer.

Various stages of mitotic cell division:

• Prophase
• Metaphase
• Anaphase
• Telophase

The events occurring during these phases of mitotic division are given in Table.

Events Occurring During Mitotic Cell Division