Answer:
a
Explanation:
if you take one organism out of the ecosystem it would have a huge affect on animals that eat it and plats that it eats. A lot of the animals that eat the dear would have a decrease in population because they don't have the deer to eat then the animals that eat the animals that eat the deer would also decrease because the animals that eat the deers population decrease.
It is B pair the last one
Answer:
Red blood cell ( RBC)
Explanation:
The antigens expressed on the red blood cell determine an individual's blood group. The main two blood groups are called ABO.