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%

the sugar-phosphate backbone forms the structural framework of nucleic acids, including dna and rna. this backbone is composed of alternating sugar and phosphate groups, and defines directionality of the molecule.

ecological efficiency: % of usable energy transferred as

biomass from one trophic level to the next typical is 10% efficient (90% of

energy is lost),is diagramed as the pyramid of energy flow. then osprey eagle

are tertiary consumer and the shrimp are primary consumer, so to balance

mass of shrimp (1/0.1) / 0.1 = 100 kg