Dr. jones systematically varies the temperature in the laboratory (70, 80, and 90 degrees) while holding other variables constant. she observes that the participants’ activity level decreases as the temperature increases. this illustrates

his research revealed two genetically different groups of prokaryotes, which justified splitting kingdom monera into two kingdoms. the genetic and cellular differences were so great, that these two kingdoms were eventually placed into different domains in the current three-domain system.

the answer to your question is:

c. complementary base-pairing

d. planting trees

the trees take in carbon to make oxygen.

blood enters the heart through two large veins, the inferior and superior vena cava, emptying oxygen-poor blood from the body into the right atrium of the heart. as the ventricle contracts, blood leaves the heart through the pulmonic valve, into the pulmonary artery and to the lungs where it is oxygenated.