Can someone answer the first one?

Which statement best describes a keystone species? o a. it has littlelmenetic variation. it has an extremely high population. 0 b. 0 c. it remains unaffected by all environmental changes. od. it has a strong influence on the ecosystem. 0 e. it's the first species to populate a new ecosystem.

Indicate the coat color and the proportion of offspring with that color for each of the following crosses of rabbits. assume all are homozygous. agouti x albino a) 1/2 albino, 1/2 agouti b) all agouti c) 3/4 agouti, 1/4 albino

This is the main structural axis of the plant that supports leaves, flowers and fruits; transports fluids; stores nutrients and produces new tissue.