If a person has a blood-calcium (Ca2+) level of 8 mg/100 mL of blood, which of the following mechanisms does the body use to maintain blood-calcium homeostasis?

A. The kidneys take up more Ca2+ and release vitamin D.

B. The bones release Ca2+.

C. The intestines increase reabsorption of Ca2+.

D. All of the above

Students in biology are studying the macromolecules of life. they used a calorimeter to determine the calories in various types of food. once the lab was completed, the students ate the left over food samples. monica commented that in just 6 or 7 "chews" of the saltine, it was gone; nothing but a sticky paste in her mouth. elaborate on what happened chemically while chewing the saltine. include the macromolecules present.

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.

On his trip to the galapagos islands, darwin determined that animals on the islands