How do mutations create variations in a population?

Ais a landform that is formed at the mouth of a river from the deposition of sediment carried by the river as the water flows.

Which of the following is not considered an appendage of the skin? nails glands follicles none of the above

Johnny rode his bike to a friend's house 4 blocks down the street in his neighborhood. he immediately rode back home once he realized his friend was not able to play. what was his displacement for the total bike ride? how did you determine this? what could we use as a reference point to determine he was in motion during his bike ride? why can you use it as a reference point