4. in an experiment, suppose that the wings of fruit flies were clipped short for fifty generations. the fifty-first generation emerged with normal-length wings. this observation would tend to disprove the idea that evolution is based on
a. inheritance of natural variations
b. inheritance of acquired characteristics
c. natural selection
d. survival of the fittest
5. charles darwin called the ability of an organism to survive and reproduce in its specific environment
a. diversity
b. fitness
c. adaption
d. evolution

Suggest why placing wheels under a heavy box reduces the neccessary force required to push it along at a constant speed.

Molecular models of two different substances are shown below. in the molecule on the left, the oxygen atom pulls on electrons more strongly than the hydrogen atoms. in the molecule on the right, the two oxygen atoms pull on the shared electrons with the same strength. water molecule, h,o oxygen molecule, oz when the two substances are put in the same container, they do not attract each other. why does this happen? a. they both contain oxygen. b. one is polar and one is nonpolar. c . they are both polar. d. they contain different elements.

How are gross production and net production different? a. net production is always greater than gross production. b. net production is always less than gross production. only animals have net production. d. only plants have net production. select the best answer from the choices provided