2. What is a major cause of extinctions? A. biological evolution
B. environmental change
C. carbonization and mineralization

Which best explains why viruses do not have special structures or enzymes that allow them to make their own food? viruses can use energy in living cells that they infect. viruses can replicate inside a host that they infect. viruses can cause contagious illnesses in host cells. viruses integrate their rna or dna into infected cells.

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

Amylase is an enzyme found in the human digestive system. why do you think it was important to keep the enzyme temperature above 37 degrees celsius (98.6 degrees f)? describe what might happen if the temperature decreased by 10 degrees celsius.