Answer:
B
Explanation:
I personal will go with B cause viruses attack your immune system then destroy healthy cells then copy it self through out the rest of the body.
our thyroid glands plays a main role in a human body. It secretes thyroxine and calcitonin. In which thyroxine help in growth and cellular metabolism and calcitonin helps to regulates calcium concentration in blood . If thyroid gland stops working then there is low level of calcium in our blood, which leads to mental and hormonal disorder. In this way a person's blood calcium level would be affected if his/her thyroid gland stops working.
<span>
D, because if white cattle are rr and red cows are RR, then roan cattle
are Rr. Therefore, a cross of Rr x RR would result in half RR and half
Rr.</span>
Cystic fibrosis and sickle cell diease