Carbon dioxide and oxygen cannot pass through but move in and out
Gravitropism
Phototropism
Thigmotropism
Amoebae move by growing an extension of their bodies in the direction of movement and then flowing into it. This extension is called a pseudopod because when it's fully extended it resembles a limb, despite being only an extension of the amoeba's plasma membrane.
Answer:
Mutations happen in our cells all the time. It's actually how all humans grow and change. The vast majority of mutations are harmless. Thus, they aren't avoidable.
