Suppose that a dominant allele (P) codes for a polka-dot tail and a recessive allele (p) codes for a solid colored tail. In addi
tion, 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 long eyelashes, 3 polka-dot tails and short eyelashes, 3 solid tails and short 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. 9:3:3:1 ratio (9 polka-dot tails and short eyelashes, 3 polka-dot tails and short eyelashes, 3 solid tails and long eyelashes, 1
solid tail and long eyelash)
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 long eyelashes, 3 polka-dot tails and short eyelashes, 3 solid tails and short 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. 9:3:3:1 ratio (9 polka-dot tails and short eyelashes, 3 polka-dot tails and short eyelashes, 3 solid tails and long eyelashes, 1
solid tail and long eyelash)
2 answers:
Answer:
B. 9:3:3:1 ratio (9 polka-dot tails and long eyelashes, 3 polka-dot tails and short eyelashes, 3 solid tails and short eyelashes, 1 solid tail and short eyelash)
Explanation:
The Punnett square diagram for a cross between individuals heterozygous for two traits, tail & eyelashes where dominant allele (P) codes for a polka-dot tail and a recessive allele (p) codes for a solid colored tail & dominant allele (L) codes for long eyelashes and a recessive allele (l) codes for short eyelashes is attached.
From the diagram attached, it is clear that there will be a 9:3:3:1 phenotypic ratio.
9 genotypes with dominant traits (polka-dot tails and long eyelashes) will be: PPLL, PPLl, PpLL, PpLl ,PPLl, PpLl, PpLL, PpLl & PpLl.
3 genotypes with dominant trait for one character and recessive trait for another character (polka-dot tails and short eyelashes) will be: Ppll, Ppll & PPll.
3 genotypes with dominant trait for one character and recessive trait for another character (solid tails and long eyelashes) will be: ppLL, ppLl & ppLl
1 genotype which will be recessive for both the characters (solid tail and short eyelash) will be : ppll
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