Trekian Fur is a dominant trait. Trekkies (on the planet Gomaz) from a pure-breeding population with the Trekian Fur gene are scored for their phenotypes. The two alleles at the Trekian Fur gene are T (dominant) and t (recessive).

80% of the Trekkies from this colony (genotype TT) have Trekian Fur; 20% of the Trekkies look wild-type.

Also, the penetrance of the Trekian Fur phenotype is 65% in the heterozygous Trekkies.

Pure breeding wild-type Trekkies (tt) show the Trekian Fur phenotype 10% of the time. Thus, the penetrance of Trekian Fur is 10% in homozygous wild-type Trekkies.

Problem: If two heterozygotes for the Trekian Fur gene (Tt x Tt) are crossed, what proportion of the offspring are expected to show the Trekian Fur phenotype?

A. 80%.

B. 55%.

C. 45%.

D. 50%.

E. 20%.

B. 55%.

Explanation:

TT = 80percent progeny that exhibit Trekian fur phenotype

Tt = 65% progeny exhibit Trekian fur phenotype

tt = 10% progrny exhibit Trekian fur phenotye

parent cross ; TT x Tt

progeny ; TT Tt tt

TT = 25% ; percentage of progeny that exhibit Trekian fur phenotype = 25 x 0.8 = 20%

Tt = 50% ; percentage of progeny that exhibit Trekian fur phenotype = 50 x 0.65 = 32.5%

tt = 25% ; percentage of progeny that exhibit Trekian fur phenotype = 25 x 0.1 = 2.5%

Total = 20 + 32.5+ 2.5 = 55%

nucleic acid molecules are incredibly complex, containing the code that guarantees the four different nucleotide units comprise dna, the nucleic acid of interest to the genealogist. and one of four nitrogen-containing molecules called nucleotides

a- multicellular

b-eukaryotic

c-no cell wall

d-heterotrophic

e-autotrophic