What is the origin of pioneer species in primary succession?

a) they immigrate from other areas
b) they are survivors of the ecological disturbance
c) they evolve from other organisms already present
d) they are present in the remains of dead organisms

Glutamic acid: hydrophilic or hydrophobic? positive, negative, or neutral? valine: hydrophilic or hydrophobic? positive, negative, or neutral?

Study the picture of the ocean. which is the best example of an organism’s niche shown in the picture? a. the environment contains several of the same species of coral. b. the shallow area of the ocean meets the needs of the coral and the fish. c. the ocean has fish and coral that live in the same area. d. the coral take in food from the water and provide shelter for the fish.

If a cell is placed into a hypertonic environment,what will happen to it ? a)it will shrink or shrivel b)nothing c)it will burst d) it will expand or enlarge