Which four nitrogenous bases are found in DNA? 1 guanine, cytosine, adenine, thymine
2 guanine, uracil, adenine, cytosine
3 both a and b
4 none of the above

During the winter, this species of fox has white fur, but in the summer, it has brown fur. what environmental change may have lead to this fox's fur color? snow cover increase in sun's brightness volcanic eruption global warming

Which of the following is a true statement? question 8 options: populations can't evolve, only individual organisms. individuals have adaptations that can change over time. individuals have traits that may or may not make them successful at reproduction. individuals evolve to have adaptations.

The law of thermodynamics states that energy can't be created or destroyed. to natural sources of energy on earth are the