Which of these is a possible disadvantage of biotechnology?
a. it could produce hardier crops.
b. it could be used to endangered species.
c. it could be used to develop medicines.
d. it could reduce genetic variation in crops.

What was the land like over 500 million years ago? what was under the sea?

Which characteristics are typical of a human population in the postindustrial stage?

Which statement is the best summary of the model? a-a series of aerobic and anaerobic reactions take place in cells b- the sun's energy moves through trophic levels in a food chain c-light energy is converted into stored chemical energy plants.d- food molecules are broken down in the cells if living things.