Answer AND Explanation:
In both plants and animals, the movement of water requires an osmotic pressure and a concentration gradient. When animals take in water by osmosis, the swell and burst. this is called haemolysis. Unlike in plants, when the cells take in water, they become turgid. The animal cells lack cell wall and thus they burst since the cell membrane is not elastic.
Answer:
B:The formation of two or more species from a common ancestor.
Explanation:
Answer: The genotype for the parent organism whose genotype is unknown is Ff.
Explanation: Let (F) represent the allele for purple which is dominant over (f) and (f) represent the allele for white.
The parent organism whose genotype is unknown is heterozygous for purple colour (Ff).
A cross between Ff and ff will produce four offsprings: two of which are Ff (heterozygous for purple colour) and two are ff (white).
Ff x ff = Ff, Ff, ff and ff.
Since (F) is dominant over (f), (Ff) will manifest as purple while (ff) will manifest as white. Therefore, half of the offsprings are purple while the other half are white.
See the attached punnet square for more information
Answer:
Its,
Osmosis is the movement of water across a membrane; diffusion is the movement of molecules from a higher to a lower concentration, with or without the presence of a membrane.
Explanation:
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.
