What three groups can animals be divided into based on how they get energy?

Coquina, a type of limestone, forms from shell fragments that settle on the ocean floor. what type of rock is coquina?

Which of the following sex and generation combinations directly produces the pollen tube of angiosperms? a) male gametophyteb) female gametophytec) male sporophyted) female sporophyte

How are mutations continually being generated in a population (what are some of the causes of mutatuions? ) explain