Where are the cells that make up the sinoatrial node, or pacemaker, located? a. right atrium c. right ventricle b. left atrium d. left ventricle

When does dna replication(make a copy of itself)?

Which of the following are false concerning microbes? a. microbes generate oxygen through photosynthesis.b. the primary role of microbes on the planet involves causing disease in animals and humans.c. microbes produce vitamins in the intestines.d. microbes play a role in breaking down waste and decomposing dead organisms.

What is the number of phosphates in an atp molecule