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). Based on the principle of independent assortment 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. 3 yellow-eyed with thumbs: 1 red-eyed without thumbs.
B
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a. water c. oxygen b. hydrogen d. NADH
Amish populations in Lancaster County, Pennsylvania have high rates of a rare form of dwarfism. The recessive allele that codes for this disorder is found in 1 of 14 individuals in this Amish population, in contrast to 1 in 1,000 in the general population. In Ohio, an Amish population suffers with higher than normal rates of cystic fibrosis and a host of other genetic diseases so rare that some have not yet been named. What factors have caused such severe genetic problems in these two communities?
What will be an ideal response?
It is essential for heart muscle cells to beat in a coordinated fashion. The cell junctions that would best facilitate this are
A) basal bodies. B) anchoring junctions. C) tight junctions. D) gap junctions.
Explain how genetic mutations that cause neurodegenerative disorders such as Huntington disease and Alzheimer disease can also cause abnormal behavior
What will be an ideal response?