How does the extinction of species affect humans? A. Extinction generates new sources of medicine.
B. Extinction upsets the natural cycling of nutrients,
C. Extinction helps keep air and water clean.
D. Extinction makes the environment more pleasant.

Color blindness is a recessive trait. the gene for color blindness is on the x chromosome. the family tree below shows the trait of color blindness. the only unknown is the mother in the first generation

Which of the following is not a defining characteristic of plants?

Multicellular organisms use cell division, mitosis, for growth and the maintenance and repair of cells and tissues. single-celled organisms may use cell division as their method of reproduction. regardless of the reason for mitosis, the process ensures genetic continuity. what is the step in the cell cycle that ensure genetic continuity?