When scientists compare molecular clocks between species, they have to use the same segment of DNA. Which of these statements
would explain why that is necessary?
A. Not every segment of DNA mutates.
B. Different genes mutate at different rates.
C. Species accumulate neutral mutations at random rates.
D. All mutations cause harmful effects.
Check Answer

Study the diagram of a desert food chain . what would most likely happen if the kangaroo rats were killed off and removed from the food chain ?

How do tides affect the organisms living in intertidal zones? a. no organisms live in intertidal zones due to the tumultuous environment. b. the mechanical forces of the waves keeps the organisms clean. c. only plants live in intertidal zones because the animals float away with the waves and never return. d. the mechanical forces of the waves can dislodge the organisms from their habitat.

What element is able to combine with itself and hydrogen to form large molecules ?