Answer:
Explanation:
Meiosis is a form of cell division that occurs in the sex cells of organisms. It ensures the reduction of a diploid cell to an haploid cell to allow for the formation of a diploid zygote after fertilization (contribution of both parents haploid sex cells to give a diploid zygote). Thus, this process is very essential and important.
The reduction is accomplished by 2 divisions after the duplication of chromosomes
- first division: separation of homologous pairs of chromosomes (this reduces the total in half)
- second division: separation of sister chromatids of a chromosome.
The rearrangement in meiosis occurs by crossing over/genetic recombination.
This is the exchange of genetic material between homologous pairs of chromosome bringing about a rearrangement and genetic variation
An example of a chromosomal abnormality that arises as a result of defects in this process is the Down Syndrome which is caused by a nondisjunction of the chromosomes 21 pair in a sex cell.
This condition produces offsprings that have some characteristic facial features, short stature etc
Answer:
B. Multipotent cells
Explanation:
Multipotent stem cells are the one that develops from pluripotent stem cells during embryonic development. The multipotent stem cells are the stem cells which have specific functions. These cells develop into specific cell types to replace the older cells.
For example, keratinocytes are the multipotent cells of the skin that produce new skin cells. Spermatogonia are the multipotent cells present in testes so that they can form sperms.
Answer:
Explanation:
Common insect adaptations include an exoskeleton (outer skeleton), camouflage, wings, the ability to have lots of babies, and adapted legs and mouthparts
Answer:
a forest of trees and undergrowth plants, inhabited by animals and rooted in soil containing bacteria and fungi, constitutes a biological community.
Explanation:
