1. which does not play a role in maintaining blood concentrations when calcium levels are low? a. parathyroid hormone increasing intestinal production of active vitamin d b. activated vitamin d decreasing kidney excretion of calcium c. activated vitamin d increasing intestinal absorption calcium d. parathyroid hormone increasing kidney production of active vitamin d e. activated vitamin d increasing release of calcium from the bone

Explain why methicillin resistant staphlococcus aureus (mrsa) is more prevalent now than it was only 30 years ago. a. antibiotics cause mutations in staphlococcus aureus that lead to an increase in the number of methicillin-resistant strains. b. methicillin resistance causes an infection to spread more rapidly.c. frequent and inappropriate use of methicillin-type antibiotics has provided selective pressure that has resulted in an increase in the proportion of methicillin-resistant strains of staphlococcus aureus.d. diseases like aids have made people more vulnerable to infections from staphlococcus aureus.