Which of the following statements about positive feedback mechanisms is not true? a.
Positive feedback mechanisms can result from human activity.
b.
Positive feedback mechanisms can occur naturally.
c.
Positive feedback mechanisms lead to increased change.
d.
Positive feedback mechanisms reduce change in a system.

Describe the change in phase and temperature as water moves from the oceans to the atmosphere and then returns to earth again as rain. a) evaporation : temperature increases; condensation : temperature decreases; precipitation (rain) : temperature decreases b) evaporation : temperature increases; condensation : temperature decreases; precipitation (rain) : temperature increases c) evaporation : temperature decreases; condensation : temperature decreases; precipitation (rain) : temperature decreases d) evaporation : temperature increases; condensation : temperature increases; precipitation (rain) : temperature decreases

Which enzyme is responsible for “unzipping" the dna by breaking the hydrogen bonds between the nucleotides?

Fossils of ancestors of the modern horses show a small 4-toed almost dog-like browsing animal named eohippus over time the horses got larger lost toes and changed to a grazing diet what is the best explanation of why this change occurred