Genetic studies of an animal show that eye color is controlled by an autosomal gene with the dominant
allele (R) for red eye color and the recessive allele (r) for yellow eye color. A second autosomal gene
has the dominant allele (T) leading to paws with thumbs while the recessive allele (t) codes for paws
without thumbs. The genetic cross RRTT ? rrtt creates offspring with genotype RrTt. One of those
dihybrids is mated in a testcross (RrTt ? rrtt). If the two genes are completely linked (no
recombination occurs between them), then the testcross should produce offspring with the phenotype
ratio
a. 3 red-eyed with thumbs: 1 yellow-eyed without thumbs.
b. 1 red-eyed with thumbs: 1 yellow-eyed with thumbs: 1 red-eyed without thumbs: 1
yellow-eyed without thumbs.
c. 1 red-eyed with thumbs: 1 yellow-eyed without thumbs.
d. 9 red-eyed with thumbs: 3 yellow-eyed with thumbs: 3 red-eyed without thumbs: 1
yellow-eyed without thumbs.
e. 1 yellow-eyed with thumbs: 1 red-eyed without thumbs.
C
You might also like to view...
How did the concept of biogeography shape Darwin's thinking?
What will be an ideal response?
Sepia apama cuttlefish mollusk males and females
A. live in populations of equal proportions, producing equal probability of reproductive success. B. can't mate successfully unless they are among the larger individuals in the population. C. are opportunistically hermaphroditic, able to mate as either male or female depending on the population needs. D. are sexually dimorphic, having different arm lengths and colorations. E. mate during the warm spring season.
To dissect means primarily
a. to cut open. b. to remove all internal organs. c. to expose to view. d. all of the above.
The Dlx gene encodes a transcription factor that signals clusters of embryonic cells to ____ and gives rise to an appendage.
A. fold into the cardiac muscle B. protrude from the body C. form reproductive structures D. induce apoptosis in cells lining the appendages E. develop into the immune system