<h2>b) option is correct </h2>
Explanation:
- Some bacterial toxins cause disease by altering the activity of G protein, cholera toxin is one of them
- Cholera toxin catalyse ADP ribosylation of Gs and blocks GTPase activity thus Gs GTP become permanently active
- Constitutive activation of Gs protein continuously induce adenylyl cyclase, cytosolic cAMP level rises that leads to activation of protein kinase A (pKA)
- Activated pKA catalyse phosphorylation of two transmembrane proteins of intestinal epithelial cells:
- CFTR cause excessive outflow of Cl- ion and Na+ H+ exchange cause efflux of Na+ ion, both enters in gut and form Na+ Cl-
- Na+Cl- leads to outflow of water from the gut, resulting in diarrhea and dehydration and this condition may cause death of organisms due to loss of water and ions
Answer:
D. helps maintain membrane fluidity
Explanation:
Mathematically the it would be D
but scientifically since eventually food and resources will start becoming scarce it would be A then as the ecosystem recovers it goes back to D <span />
C no because many species went extinct without leaving fossils behind
