The dichotomous key (ERGENT HELP) A

helps classify organisms through yes or no questions.

B

unlocks the names of different organisms in a family.

C

groups animals that lay eggs with animals that have live births.

D

asks multiple questions about how organisms behave and act.

What does polymerase chain reaction (pcr) do? o a. separates dna fragments by size o b. cuts a dna sample into fragments o c. provides an overall picture of a person's chromosomes o d. makes more copies of a sample of dna

Drag each tile to the correct box. the body monitors the levels of oxygen in the blood to regulate breathing. isabel is running in a marathon and is near the finish line. she feels out of breath. how will her nervous system work to generate a reaction? arrange the tiles in chronological order. isabel's breathing rate increases. sensory receptors in the arteries detect low oxygen levels. the brain sends signals through motor neurons. sensory neurons generate an impulse. the central nervous system relays an impulse to certain brain regions.

Which of the following human activities resulted in the growth of the north american deer population?