The number of individuals of a species per unit area is known as?

Leila has dimples because she received a gene copy from her father that coded for dimples. this means that dimples are an example of a trait that is

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

Which of the following is not associated with invasive species?