Answer:
A. Natural killer (NK) cells are activated in response to interferons or macrophage and Major histocompatibility complex (MHC) and allows direct apoptosis of virus.
Viruses can invade NK cells by inhibiting MHC from reaching the cell surface. Using stimulating the inhibitory receptors and disrupting the activating receptors, viruses can avoid NK cells. MHC act as a ligand of inhibitory receptor, and when bind with inhibitory receptor allows damage to NK cells.
So, if i would be a virus i will use inhibitory receptors stimulation to avoid NK cells.
B. Bacteria are killed by phagocytic immune cell macrophages by engulfing them.
Bacteria avoid macrophages by escaping from phagosome before the lysosome fuses as lysosomal chemical kill the bacteria and some bacteria prevent acidification of the phagosome.
C. Parasites can avoid macrophages by modulating the host's cell cytoskeleton to block proper phagocytosis.
D. Bacteria can avoid dendritic cells by avoiding lysosomal degradation and prevent antigen presentation on MHC molecules that will modulate the entrance to DCs.
E. B cells are responsible for producing antibodies. Activation of B-cell depends on positive and negative signals transmitted through the B-cell receptor (BCR), so genetic polymorphisms and mutations affects the positive and negative signals. If mutation is done showing negative signal, B cell will not the activate and no antibodies will produce.
A MOTILE EUKARYOTE
According to the question, the new organism has:
1. A plasma membrane which is found in all living cells except viruses and prions.
2. Two flagella show that the organism is motile.
3. Peroxisome is a membrane bound cell organelle found in eukaryotic cell.
Answer:
Hey there!
This can be explained using the conservation of angular momentum, which the planets get attracted to the sun because of its large size, and massive gravitational pull.
Let me know if this helps, or if you need a further explanation :)
Answer:
loud cars or desterbing noises
Explanation:
The most primitive form of life is Bacteria.
C. Bacteria.
