Why do plasma cells derived from b cells have extensive endoplasmic reticulum?

What are the pros and cons of transect sampling?

What type of tree is the tallest tree in the world?

Scientists discovered fossils in several layers of the earth you see here. they found fossils of algae, snails, and clams in layer d. given that information, where do you think they found fossil evidence of simple land plants and amphibians? a. a b. e c. f d. g