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.
Evolution is caused by genetic mutations that become favorable for survival.
For example if a bird has a mutation that gives it a longer beak and it lives in an environment in which a longer beak lets the bird catch more food- the longer beak becomes a favorable trait.
Now the bird is able to survive “better” thus it lives longer(due to its ability to catch more food). Because of this it reproduces more and passes the trait on to its offspring.
Overtime this mutation takes over the population of birds in the area.
<span>There are two structures that would be found at a passive continental margin. These structures are continental shelves and continental slopes.</span>
The answer would be appropriately shaped receptors