With regard to T cell development in the thymus. How are tissue specific antigens expressed in the thymus?

7. In humans, ABO blood type is controlled by a single gene with 2 codominant alleles (I^A and I^B) and one recessive allele (i).  The population of humans in the city of Xanadu is 7568.  1874 of these people have blood type O and 1243 of these people have homozygous blood type A.  You will need to use a three-variable Hardy-Weinberg equation for this question: p² + 2pq + q² + 2qr + r² + 2pr = 1.  Note that p + q + r = 1.

a. (2 points) What are the frequencies of the I^A, I^B, and i alleles assuming this population is randomly mating and there are no significant evolutionary forces acting on the population?

b. (2 points) Estimate how many individuals in the population have each of the following genotypes: I^Ai, I^AI^B, I^BI^B, and I^Bi.

c. (2 points) Estimate how many individuals in the population have type A, type B, type AB, and type O blood.

d. (2 points) A disease suddenly emerges that kills 60% of people with type A blood (leaving 40% alive), kills 40% of people with type AB blood, kills 10% of all people with type B blood, and kills 5% of all people with type O blood. What is the frequency of each blood type in the population now?

e. (2 points) An effective vaccine is developed so the disease only affects a single generation. Using the values for the number of survivors with type O and homozygous type A blood, determine what the allele frequencies of the I^A, I^B and i alleles will be when the population of Xanadu has again reached Hardy-Weinberg equilibrium.

In peas, tall (T) is dominant to short (t), yellow (Y) is dominant to green (y) and round (R) is dominant to wrinkled (r). A purebreeding plant with tall, green and wrinkled pea phenotypes is crossed to a purebreeding plant that is short and makes yellow, round peas. When peas from this F1 generation are crossed, what is the probability of obtaining a short plant that makes yellow, wrinkled peas in the F2?

What are advantages of the study on microbial growth and product production phases and kinetics

Explain how attenuation regulates the trp operon in response to cellular levels of tryptophan

Describe what is meant by the term consensus sequences for transcription in E. coli and their significance in regulating transcription from promoters recognized by the σ70 factor.

A central question in biology is, how do we have > 200 different cell types, complete with unique cell morphologies and functions, when all cells have the same DNA (the concept of genomic equivalence). Epigenetic regulation of gene transcription is one way to explain this. Define what is meant by epigenetic regulation of gene transcription, including different general epigenetic mechanisms, and describe three different contexts of a developmental process that is associated with epigenetic changes that we have discussed in class.

1. What is the function of the nictitating membrane?
2. What is the function of the tympanic membrane? Why would a male’s tympanic membrane be larger than a female’s?
3. What are some of the characteristics of the frog that help in jumping?
4. Which duct/tube do the excretory, digestive, and reproductive system meet at?
5. How many chambers are found in the frog’s heart? Is the oxygenated blood separated from the deoxygenated blood by the chambers or is the blood mixed together?
6. How many lobes are found on the frog’s liver? Name one function of the liver.
7. Name the functions of the muscles:
   1. Gastrocnemius
8. 2. Adductor magnus
9. 3. Gracillis major
10. 4. Tiabialis anterior longus

Assume that you are responsible for decontaminating materials in a large hospital.
How would you sterilize each of the following? Briefly justify your answers.

a. a mattress used by a patient with bubonic plague
b. intravenous glucose-saline solutions
c. used disposable syringes
d. tissues taken from patients

This is normally accomplished through methylation of a cytosine:

a. paternal effect   b. imprinting   c. epistasis   d. maternal inheritance   e. aromatase

Describe what it means for interactions to be selfish by using the concepts of actor and recipient.

A mountain climber ascends to an altitude where the partial pressure of oxygen in the atmosphere is very low.

1. What happens to levels of erythropoietin in the blood after a period of time at high elevations?

2.How does a low concentration of oxygen in the alveoli affect the state of contraction of pulmonary arterioles?

3.Explain why pulmonary edema is a symptom of altitude sickness