Which conditions are necessary for natural selection? Check all that apply.
Populations do not have genetic variation.
Populations have genetic variation.
The environment changes.
The environment stays the same.
Organisms must have specific traits in order to survive and reproduce.
O Organisms with any traits will survive and reproduce.

The answer is B, C,E

Which of the following is not am example of a polymer? protein nylon kevlar concreta

Which of the following situations is impossible? a) an object has velocity directed east and acceleration directed east. b) an object has zero velocity but non-zero acceleration. c) an object has constant non-zero velocity and changing acceleration. d) an object has velocity directed east and acceleration directed west. e) an object has constant non-zero acceleration and changing velocity.

The atoms in a nickel crystal vibrate as harmonic oscillators with an angular frequency of 2.3 × 1013 rad/s. the mass of a nickel atom is 9.75 × 10-26 kg. what is the difference in energy between adjacent vibrational energy levels of nickel? (h = 6.626 × 10-34 j • s, , 1 ev = 1.60 × 10-19 j)