Question

Meiosis occurs in which of the following?
a. Diploid cells
b. Haploid cells
c. Mostly haploid cells but occasionally diploid cells
d. Mostly diploid cells but occasionally haploid cells.

Answer 1

Hint: The process of division a single-cell twice to produce four cells is known as meiosis. It contains half the original amount of genetic information. In humans, sperm and egg cells are produced through this process.

Complete answer:
In Eukaryotic cells (sexually reproduced organs) the two successive divisions of a diploid (2N) happens by meiosis for the production of four haploid cells. Employing this, the crossing-order for genetic variation of the haploid cells occurs in the segregation of paternal and maternal chromosomes.

The process involves, firstly the duplication of chromosomes of diploid cells occurs. Then the four haploid cells (each with half of the parental cell chromosome) are produced through two successive divisions.

Meiosis takes place only in sexually reproductive organisms. Sometimes the haploid gametes are produced which are further fused to haploid sperms depending on the type of organisms. The produced haploid spores are further divided by mitotic cell division for the production of the unicellular or multicellular organism.

The product of meiosis in animals are gametes, where the somatic body cells are diploid.
In some fungi such as yeast, unicellular algae, meiosis takes place immediately after the fusion of haploid cells for the production of haploid unicellular or multicellular organisms.

Both the haploid and diploid multicellular stages occur in some plants and algae. The sporophyte is the multicellular diploid stage. And the haploid spores are produced by the process of meiosis. A gametophyte is generated from the haploid multicellular spore. Therefore the gametes are produced finally by following mitotic cell division.

Hence, Option (A) is the correct answer.

Note: There are two types of cell division. They are mitosis and meiosis. The process of making new body cells is called mitosis. The process of making sperm or egg cells is called meiosis.
The five stages of cell division are given as follows: prophase, prometaphase, metaphase, anaphase, and telophase.