In herbaceous stems, which tissue carries water from the roots to the leaves? bark
phloem
seed
xylem

If the birth rate of a population of dolphins is 2.0, the death rate is 0.5, and the population size is 100, what is this dolphin's population growth?

Other than earth, is also known to have magnetic pole reversal? a: venus b: mars c: earths moon d: the sun

Asquirrel population lives in an area. over many years, a river in that area grows wider and stronger, eventually forming a canyon. the squirrel populations on the two sides of the canyon can no longer mate with each other and ultimately form distinct species. this is an example of