The pancreas releases glucagon, which allows a) high blood sugar levels to be reduced by positive feedback. b) high blood sugar levels to be reduced by negative feedback. c) low blood sugar levels to be increased by positive feedback. d) low blood sugar levels to be increased by negative feedback.

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.