Correct answer: B). With fewer contractions
The main function of a contractile vacuole is to maintain the sufficient amount of water in the protoplasm of the cell. For the freshwater amoeba contractile vacuole is needed to pump water and maintain a osmoregulation.
But when it is kept in sea water, more contraction is required to expel the water out of the cell in order to make the environment inside amoeba same as of sea water.
Answer: Well, populations never evolved than one human might have gone extinct due to many different viruses and sicknesses but other animals might not be extinct. If populations never grew more then that would be because we could not overpower dome viruses. If we never. If we never evolved animals like a Carrier pigeon would not be dead or extinct today.
The answer is plankton are floaters. Plankton and nekton are both marine aquatic organisms. The main difference between the two is that plankton tend to float and be carried by water currents while nekton are organisms that swim against the current of the water. Plankton are passive swimmers while neekton are active swimmers.
asexual is from one singular parent . offspring comes from one singular cell . that should help you work through that !
