Biology Questions

Random mutations are the ultimate source of genetic variation. Mutations are likely to be rare and most mutations are neutral or deleterious, but in some instances, the new alleles can be favored by natural selection. Polyploidy is an example of chromosomal mutation.

Mutations are changes in the DNA. A single mutation can have a large effect.

1) mutation - an alteration in DNA sequence, various types

2) intragenic recombination - results in entirely new associations of genes not present in either parental genome.

Two forms of intragenic recombination:

a) crossing over
b) independent assortment
3) reticulation – acquisition of genetic material from unrelated or relatively unrelated sources (e.g., hybrid species, horizontal gene transfer).

Deep sea animals cannot produce food as there is no light. They have to depend upon the fall out of organic debirs raining down on them from surface layers. Hence they are detritivores.

Mumps: This is a swelling caused by inflammation of parotid glands placed in front of our ear region. The Inflammation is caused by a virus.

In a nucleosome, the DNA is wrapped around histone octamer.

A tertiary consumer is an animal that obtains its nutrition by eating primary consumers and secondary consumers.

Usually tertiary consumers are carnivorous predators, although they may also be omnivores, which are animals that feed on both meat and plant material.

Tertiary consumers often occupy the top trophic level, and so are predated by no other animals; in this case they are called "apex predators". However, when they die their bodies will be consumed by scavengers and decomposers.