Q1: The answer is seasonal changes.
Q3: The answer is sodium.
Q4: Not sure, sorry.
Q5: And then I think it is A for this one, but I am not sure.
Answer:
Bacteroides plebeius which is present in the gut humans have the same genes to marine bacterium Zobellia galactanivorans.
Explanation:
many researchers findout that bacteroides plebeius acquired functional porphyranase and agarase genes from a marine bacterium called Zobellia galactanivorans. Zobellia galactanivorans is a marine bacterium which has the ability to digest complex polysaccharides such as agarose and porphyran. so due to similar genes, Bacteroides plebeius also digest polysaccharides such as agarose and porphyran present in sea weed.
