Biology Questions

The support cells of the nervous system are Glia, also called glial cells or neuroglia. In the central nervous system, there are four types of supporting cells. They are ::

* Astrocytes

* Microglial cells

* Ependymal cells

* Oligodendrocytes

The process by which bacteria convert nitrogen gas (N2) into ammonia (NH3) is called Nitrogen Fixation.

The conversion of nitrogen from one form to another in the nitrogen cycle is carried out primarily by Nitrogen Fixing Bacteria such as Azotobacter.

DNA is copied during a process called Transcription. It is the first step of gene expression, in which a particular segment of DNA is copied into RNA by the enzyme RNA polymerase.

23 chromosomes are in a human gamete.

Human somatic cells have 46 chromosomes(23 pairs) but a gamete(germ cell) gets half the amount, i.e. 23 chromosomes, (one from each pair). There will be half the number of chromosomes an organism has in its somatic cells (all other body cells except gametes).

For example in humans, the somatic cells contain 46 chromosomes which are the diploid number (2n) and each sperm and egg has 23 chromosomes where one of them is the sex chromosome.

Lobsters, like snails and spiders, have blue blood due to the presence of hemocyanin, which contains copper. In contrast, vertebrates and many other animals have red blood from iron-rich hemoglobin.