Which situation involves mainly biotic factors? * 1 point
A drought causes crops to die, and as a result cattle go hungry.
A fungus wipes out a bat population, which allows the mosquito population to
increase and spread disease to people.
A drop in the pH of ocean water prevents coral from growing properly, which harms
the coral reef ecosystem.
Dust from a volcanic eruption blocks sunlight to Earth's surface, and as a result the
weather gets colder.

Next pretest: evolution select the correct answer in a laboratory population of flies, the female flies are gray and the males are yellowish gray. biologists observed that all the male flies had an equal chance for reproduction, but the male flies with the brightest colors were more likely to successfully reproduce. what phenomenon could explain such a change? a sexual selection b. disruptive selection c. stabilizing selection d. directional selection

Predict the results of a two base insertion or deletion in a strand of dna that codes for a protien, how does this differ from a three base insertion or deletion?

What are some natural processes that represent physical and chemical changes?