Receptors detect changes in the environment. For a stimulus to elicit a response, certain cells must have an appropriate receptor. Stimulation of the receptor initiates a specific signal pathway.
Is there a multiple choice or fill in the blank?
Answer: A. Speed
Explanation: Hope it Helps!
The correct answer is microglia.
<span>Microglia is glial cells found in the central nervous system with the protective role. Because they are the resident macrophage cells, they act as the first and main form of active immune defense. Microglia is constantly cleaning the CNS for plaques, damaged or unnecessary neurons, and infectious agents, like viruses or other microorganisms.</span>
In nondisjunction, if members of a pair of homologous chromosomes do not move apart during meiosis I or sister chromatids fail to separate during meiosis II, this means one gamete receives 2 of the same kind of chromosome and i<span>f either one of these abnormal gametes unites with a normal one at fertilization, the zygote will also have an abnormal number of particular chromosomes; which is known as an aneuploidy.</span>