Help please! I’m so stuck on this!

How does natural selection change thephenotypes within a population over time?

The negative change found inside the plasma membrane is created by potassium ions sodium ions hydrogen ions chlorine ions

Matthew decided he wanted to hike up mount everest. on his way to the top, it began to snow and the temperature dropped to -10°f. matthew forgot to wear a heavy jacket so his body began to shiver beyond control. in this case, matthew's body shivering is the to a drop in temperature. * 0 points reflex stimuli responce environmental facto