Doctors often use certain medications to treat infections. A few people have a reaction to some of these medications, such as itching, swelling, or trouble breathing. This is an example of 1. using antibodies to cure a medical problem
2. the body's immune system overreacting to a usually harmless substance
3. the body creating a mutation to fight unknown pathogens
4. a vaccine causing the body to produce antigens against the infection

Melissa lives in a town called greendale. she discovers that when she lights a match and holds it near her kitchen faucet, the little flame grows into a larger fire. melissa is surprised because she thought the water would extinguish the flame rather than ignite it further. her mother tells her that the water might be contaminated with dissolved methane, a primary component in natural gas. melissa investigates the matter and finds that cases of methane contamination started shortly after a company began fracking for natural gas in the area. based on this information, which three statements are plausible consequences of fracking in greendale?

The diagram shows a fossil of an ancient whale skull and a skull of a present-day whale. the ancient whale is extinct and is believed to be an ancestor of the present-day whale. what do these skulls most likely show that supports darwin’s theory of evolution? all populations can adapt and survive. only some organisms have a common ancestor. populations change slowly over time. populations rapidly become extinct.

Mike has a problem with his testosterone. he is unable to produce enough. which will most likely be affected by his inability to produce testosterone? check all that apply.