Question

Suppose that a dominant allele (P) codes for a polka-dot tail and a recessive allele (p) codes for a solid colored tail. In addition, suppose that a dominant allele (L) codes for long eyelashes and a recessive allele (l) codes for short eyelashes. If two individuals heterozygous for both traits (tail color and eyelash length) mate, what's the probability of the phenotypic combinations of the offspring? A. 1:1 ratio (half are polka-dot tails and short eyelashes; half are solid tails and long eyelashes) B. 9:3:3:1 ratio (9 polka-dot tails and short eyelashes, 3 polka-dot tails and long eyelashes, 3 solid tails and short eyelashes, 1 solid tail and long eyelash) C. 1:1 ratio (half are polka-dot tails and long eyelashes; half are solid tails and short eyelashes) D. 9:3:3:1 ratio (9 polka-dot tails and long eyelashes, 3 polka-dot tails and short eyelashes, 3 solid tails and long eyelashes, 1 solid tail and short eyelash)

Answer 1

The correct answer is D

As you can see in the picture presented below when two heterozygous parents
(PpLl x PpLl) cross, you get a 9:3:3:1 ratio of the offspring.
9/16 are dominant for both traits ( have polka-dot tails and long eyelashes)RED
3/16 are dominant for only one trait ( polka dot tails, short eyelashes)YELLOW
3/16 are dominant for the other trait ( solid tails, long eyelashes)LIGHT BLUE
1/16 are recessive for both traits ( polka dot trails, short eyelashes)DARK BLUE