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. 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) B. 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) C. 1:1 ratio (half are polka-dot tails and long eyelashes; half are solid tails and short eyelashes) D. 1:1 ratio (half are polka-dot tails and short eyelashes; half are solid tails and long eyelashes)

Answer 1

You need to set up a Punnet square to figure this out (attached).
From this you will see that you get quite a number of putative offspring:
PPLL=polkadot/long = 1
PPLl=polkadot/long = 2
PpLL=polkadot/long = 2
PpLl=polkadot/long = 4
Ppll=polkadot/short = 2
PPll=polkadot/short = 1
ppLL=solid/long = 1
ppLl=solid/long = 2
ppll=solid/short = 1
(16 total potential offspring)

Regroup according to traits:
polkadot/long = 9
polkadot/short = 3
solid/long = 3
solid/short = 1

ANSWER: B