I'm not entirely sure and this response is late but I'm pretty sure it's when the central vacuoles lose their water and can no longer support the cell. When the vacuole of a cell is full it pushes outward against the cell wall. When it has nothing in it, you can assume that because the vacuole is so big and is such a big component of this that this would be the answer.
Natural selection leads to increases in the mean fitness of populations and so will reduce the frequency of disease-associated alleles, but other evolutionary processes, such as mutation and gene flow, may introduce or increase the frequency of these deleterious alleles.
It gets blurry and further away because it is not changing
Answer:
i believe the answer is c
Waxing crescent
First quarter
Waxing gibbous
Full moon
Waning crescent