Answer: B
Explanation:
The T helper cell needs to acttivate the T cyctotoxic cell in order for the Tc cell to go do its work.
Once the TC cell is active it interacts with MHC-1 proteins on the surface of the infected host cell, this allows the Tc cell to recignise the host cell and begin secreting cytotoxins (perforins and granzymes) in order to degrade the infected cell and cause apoptosis (controlled cell death)
Answer:
B because homozygous is the alleles in the genotype
Explanation:
Sex cells will always contain half of the number of chromosomes needed for a being. So if a fishes sperm cell contains 12 chromosomes and the ovum also contains 12 chromosomes then when fused together they will have 24 chromosomes in total.
In order for the process of the fish to even be made the sperm and ovum must be fused together. Therefore the number of chromosomes that would be found in the cells forming the gills is 24 chromosomes.
<span>The purpose of the kidneys is to filter waste from the blood, and other things like water, glucose, amino acids, some minerals/vitamins, and other small molecules can also get filtered out. Reabsorbtion of water in the kidneys allows the body to maintain a fluid balance (drink a lot and you pee more cause you have an excess of water). As for the other aforementioned things, they're often needed for metabolic processes (such as certain enzyme functions) so loosing it to waste decreases efficiency and efficacy of other bodily processes. </span>
<u>levels of organization </u>
from the smallest units of life to the largest units of the environment :
organelles >>> cells >>> tissues >>> organs >>> organ systems >>> organisms >>> populations >>> communities >>> ecosystems >>> biosphere