I believe the answer is A. decomposition ans parasitism
C waning crescent and waxing crescent
Amoeba acquires it food by endocytosis, that is, a small region in the plasma membrane which ultimately forms a intra-cellular membrane-bound vescicle. It engulfs it food using its pseudopodia (temporary protrusion of the surface of the amoeboid cell used for feeding and movement) and forms a vacuole around it. When the food is already trapped inside, it releases a digestive enzyme to digest it. Intake of liquid particles is pinocytosis (cell drinking) while intake of solid particles is phagocytosis (cell eating).
Answer:
Positive natural selection.
Explanation:
The positive natural selection is a type of natural selection that increases the frequency of an allele or trait when it is advantageous for the population. What happened in the example is that the mouth with the slight change in morphology (trait) was more advantageous for the population in the south in relation to the ancestral morphology (still preserved in the population in the north), and therefore its frequency increased. This, in turn, is due to the fact that the food (prey) is not the same in the two habitats (north and south). The specific prey in the south, caused the new morphology to be selected, (increasing the frequency of individuals with the new mouth), becasue probably that trait allows the trouts in the south to hunt more effectively.
