What is the result of crossing over? A. phenotype
B. mutations
C. increase cell number
D. genetic variation

What does all of the organ system in a human form

The deserts of the sahara and australia are associated with

How have high taxes on tobacco products impacted the number of people who use them? a. the number of tobacco users has increased. b. the number of tobacco users has decreased. c. the number of tobacco users has not changed. d. the number of adolescent tobacco users decreased, while the number of adult users increased