Which molecule is found in both dna and rna?
a. ribose
b. uracil
c. phosphate
d. amino acid

What would be the result if crossing over did not happen during meiosis in humans? a. there would be less genetic variation in humans. b. parents would be more likely to look like their children. c. the human population could not reproduce. d. children would have more chromosomes.

Natural selection changes allele frequencies because some survive and reproduce more successfully than others.

The relationship between intron and exon