Biology Answers

Using genetic engineering techniques, you have created a set of proteins that contain two
(and only two) conflicting signal sequences that specify different compartments. Predict which
signal would Wln out for the following combinations. Explain your answers.

A. Signals for import into the nucleus and extracellular matrix.

B. Signals for export from the nucleus and import into the peroxisome.

C. Signals for import into mitochondria and retention in the Golgi complex.

Consider three genes, Aa, Bb and Cc, each of which affects a different character. The three genes are located on different chromosomes. Calculate the probability of obtaining: a) An Aa BB Cc zygote from a cross of Aa Bb Cc x Aa Bb Cc b) An Aa BB cc zygote from a cross of aa BB Cc x AA bb CC

In rabbits, the coat color black dominant (B) over brown(b). Short hair is dominant (S) over long (s). Cross a homozygous black heterozygous short-haired male and a brown homozygous long-haired female. What is the phenotypic ratio?

In Shorthorn cattle, both red coat color and white coat color are true breeding. Crosses of red cattle x white cattle produce offspring that are uniformly reddish brown but thickly sprinkled with white hairs. Crosses of roan x roan produce 1/4 red: 1/2 roan: 1/4 white. What kind of genetic inheritance can explain these results?

In the jimsonweed, purple flowers are dominant to white. When a particular purple flowered jimsonweed is self-fertilized, the progeny are 27 purple-flowered and 10 white flowered progeny(approximately 3:1 ratio). What proportion of the purple flowered progeny will breed true (AA) ? What proportion of the white-flowered progeny will breed true (aa)?

In our population the incidence of polyposis of the large intestine is 1:8,000. The disorder is determined by the autosomal dominant allele. What is the frequency of disease-causing allele in the population?

We know that the most common form of of color blindness results from an X- linked recessive gene. A couple with normal color vision has a daughter with normal vision and a son who is color-blind. What is the probability that the daughter is a carrier for the color-blindness allele?

Assume that congenital dislocation of the lumbar joint is dependent upon the action of a dominant allele
with 25% penetrance (the frequency with which a dominant or homozygous recessive gene manifests itself
in the phenotype of an individual). Frequency of the disorder is 6:10,000. State the number of homozygous
individuals for the recessive allele.

1. A warthog weighs 100 lbs. If a cheetah eats the warthog, approximately how many pounds will be used for energy by the cheetah?

lactulose is soluble but not digested or absorbed in the human intestine. Why is lactulose used to help people suffering from constipation using the idea of water potential.