Answer:
Astrocytes
Explanation:
Astrocytes are the most abundant cells in the central nervous system that twine around nerve cells supporting the brain and spinal cord. They perform many functions; such as providing the nuerons with nutrients, control the blood brain barrrier and blood flow. Astrocytes are basically responsible for maintaining the central nervous system homeostasis.
One example: The improvement in science and technology over the years has decreased the infant mortality rate. Since more babies live, we have a higher population.
Also, with increases in science and technology, there are many diseases that were once considered fatal that are now easily treated. This has also led to a higher population.
A culture medium consisting of agar, human blood, and beef heart is a
B) Complex medium
The genes that survive and flourish in a species are the strong ones. Strong genes evolve into the next generation, while weaker ones die.