Here is a food chain in yellowstone national park: willow tree_> elk > gray wolf how would you expect the reintroduction of gray wolves to yellowstone national park to affect this food chain? a. both elk and willow populations would increase. b. the elk population would decrease while the willow population would increase. c. the elk population would increase while the willow population would decrease. d. both elk and willow populations would decrease.

Ethan is giving a highly technical presentation on biomedical engineering involving several working models, computerized graphs, and video clips to a small group of doctors, scientists, and engineers. Which two characteristics of public speaking should he be most concerned with during his preparation?
a.
delivery and audience
b.
noise and delivery
c.
channel and message
d.
None of the above.

1. true.2. true.3. true.4. false.5. true.the concept of darwin's theory of evolution involves the idea that there are limited resources in a given living environment and that the organisms which live within have variations in their genetic make up due to random mating. the ones with beneficial genetic variations can express certain traits which give them an upper hand in surviving and reproducing in the said environment compared to ones who may have a more disadvantageous variation in traits. over time, the organisms with an upper hand will survive and reproduce more frequently and pass on their beneficial genes while the others die. the result is evolution, where we observe (usually, but not always) eventually, phenotypic distinct changes.

The answer is observations and interpreting.