Robert decides to go for a run when he gets home from school. As he begins running, his breathing rate starts to increase. What are the mechanisms that cause his breathing rate to increase?

A.
The respiratory control center senses the need for more oxygen, which causes the trachea to push and pull air more forcefully.
B.
The diaphragm senses the need for more oxygen, which causes it to expand and contract more quickly in order to inflate and deflate the lungs.
C.
When oxygen levels in the blood decrease, the respiratory center sends signals to the diaphragm to increase the rate at which it contracts and relaxes.
D.
When carbon dioxide levels in the blood decrease, the respiratory center sends signals to the alveoli to increase the volume that they expand.

Tlymphocytes mature in the? a. thyroid gland. b. bone marrow. c. spleen. d. thymus.

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.

Which one is an advantage of external fertilization a. the offspring are genetically identical to the parents b. more eggs can be fertilzed at one time c. more sperm can be released at one time d. more protection is available for developing plz