What effects do keystone specie shave on an ecosystem?
A. They make prey species extinct
B. They reproduce biodiversity
C. They keep populations of species balanced
D. They cause primary disturbances.

If two parents who's blood types are both b produce a child that has blood type o, what can you say about the parent's genotybes? oa) one is ii ob) one is ibi oc) both are bi od) nothing, this is impossible

The response is the basis for vaccination. primary secondary tertiary none of the above

In "the man in the water," what was the remarkable occurrence that rosenblatt reported?