Heifer – a cow that has not borne a calf, or has borne only one calf. In North America, a typical farm has about 100 milk cows and as many young female stock called heifers. The heifers are raised as replacement cows.
Coral lives a symbiotic life. Inside the sac of each coral polyp lives one-celled algae called zooxanthellae.Algae gives off oxygen and other nutrients that the coral polyp needs to live and in return the polyp gives the algae carbon dioxide and other substances the algae needs.
EXAMIANS