Answer:
The correct answer will be option-B.
Explanation:
Meiosis is a type of cell division which proceeds in two stages: meiosis I and meiosis II and result in the formation of four daughter cells.
The meiosis I is known as the reductional division as two daughter cells are formed with reduced ploidy level that is haploid cells from diploid cells. The cells formed contains chromosomes with two chromatids as the DNA amount gets doubled after the DNA synthesis.
Thus, Option-B is the correct answer.
The following are the characteristics of Cnidaria:
1. The organisms have specialized stinging cells known as cnidocytes.
2. Two types of body plans exist, that is, polyp and medusa.
3. The phenomenon of alternation of generation is observed.
The following are the characteristics of Porifera:
1. The organisms lack symmetry.
2. The adult forms are sessile.
3. The organisms obtain food by filtering water.
Answer:
A decrease in biodiversity causes a decrease in ecosystem stability, because a change to one organism will have a greater impact on the entire ecosystem. With greater biodiversity, the loss of one type of organism could be moderated by the adaptation of other organisms to fill its role.