If a person has a blood-calcium (Ca) 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 Ca? and release vitamin D.
B The bones release Ca?
C The intestines increase reabsorption of Ca?
D All of the above

Hummingbirds drink nectar from flowers, while robins eat plant seeds. what does this reduce?

Which of the following is the source of energy for photosynthesis? a.) glucose b.) chlorophyll c.) carbon dioxide d.) sunlight

Duchenne muscular dystrophy is a serious condition caused by a recessive allele of a gene on the human x chromosome. the patients have muscles that weaken over time because they have absent or decreased dystrophin, a muscle protein. they rarely live past their twenties. how likely is it for a woman to have this condition? a) women can never have this condition.b) one-fourth of the daughters of an affected man would have this condition.c) one-half of the daughters of an affected father and a carrier mother could have this condition.d) only if a woman is xxx could she have this condition.