Which of the following statements depend on the absolute dating of events?

dinosaurs went extinct before monkeys evolved.
birds separated from dinosaur relatives 120 million years ago.
the oldest earth rocks are 3.9 billion years old.
in undisturbed rock layers, we find older rock layers beneath younger rock layers.

Taq polymerase is an enzyme isolated from the organism thermophilus aquaticus. this organism has been found living in the hot springs of yellowstone national park. this enzyme is used to copy human dna from crime scenes. most reactions are performed at ranges similar to those of the human body; however, what considerations should be made for optimum use of this enzyme? view available hint(s)taq polymerase is an enzyme isolated from the organism thermophilus aquaticus. this organism has been found living in the hot springs of yellowstone national park. this enzyme is used to copy human dna from crime scenes. most reactions are performed at ranges similar to those of the human body; however, what considerations should be made for optimum use of this enzyme? the enzyme will not work on human dna.nothing should be altered.the ph should be decreased.the temperature should be raised.

Milk production during breastfeeding is increased by the suckling of a newborn from his mother's nipple. this type of feedback mechanism best describes a positive or negative

Why has two different alleles for the same trait?