If xylem tissue is plugged by gum, what other substances are prevented from traveling up the stem?

Which of the following occurs most often in a population when genetic variation and overproduction are present? some organisms have a lower reproductive success than others. some organisms have a higher reproductive success than others. some organisms have no reproductive success. some organisms do not have genetic variation.

At which point is crust neither created nor destroyed? island chain mid-ocean ridge divergent boundary transform boundary

Can ground tissue do photosynthesis