Why do we sometimes say that we have 23 pairs of chromosomes? where do the halves of the pair come from?

This is a coral reef ecosystem. many biotic and abiotic factors affect the health of this ecosystem. which set correctly pairs a biotic factor and an abiotic factor?

The leopard frog and the pickerel frog are two closely related species. in areas where their ranges overlap, the frogs will remain separate species if they

One function of the immune system is to attack the foreign cells to protect the body. in organ translate , the body recongnizes that the new organ is made of foreign cells. wha kind of medicine would you give a patient to increase the chances of transplate success