Outline the forces driving variation in allele, gamete, or haplotype frequencies in
populations and illustrate one or more with two examples involving human genetic
disorders

write 500 words

During the past several decades there has been an alarming increase in the incidence of skin cancers, including malignant  melanoma, that has been attributed to increased sun exposure.

1. Explain the possible mechanism whereby ultraviolet radiation promotes the development of malignant skin lesions.
2. Cite two important clinical signs that aid in distinguishing a dysplastic nevus from a malignant  melanoma

Eukaryotic protein x has one proline residue and two cysteine residues. The proline needs to be in the cis-configuration in the folding protein and a disulphide bond is formed between the cycteine residues in the folded protein. Discuss the folding of the protein in a solution with protein disulphide isomerases and peptidyl prolyl isomerases as well as without these enzymes. Make use of illustrations to show differences in the potential folding of protein x under different conditions.

70 year old man complains that he gets this terrible feeling "like the room is moving around" and becomes nauseated when he rolls over in bed or bends over suddenly. It usually goes  away once he has been up for awhile. He has been told that his symptoms are consistent with benign paroxysmal positional vertigo.

1. What is the pathophysiology associated with this man's vertigo?
2. Why do the symptoms subside once he has been up for a while?
3. What methods are available for treatment of the disorder?

Statistical tests: For each scenario below, identify the type of test you should use for the analysis.

79. Analyzing the effects of a drug on blood pressure level in a study with 20 people. All 20 people are tested both before taking the drug and after taking the drug.

a) paired t-test

b) unpaired t-test

c) c² test (chi-squared test)

80. Analyzing the effects of a drug on blood pressure level in a study with 30 people. 15 people take the drug and the other 15 people take the placebo.

a) paired t-test

b) unpaired t-test

c) c² test (chi-squared test)

81. Analyzing the effects on pollution on plant size in 10 different regions in the US. In each region, 20 plants exposed to pollution are measured and 20 plants not exposed to pollution are measured.

a) paired t-test

b) unpaired t-test

c) c² test (chi-squared test)

The mother of a seven-year-old boy notices that he is scratching his head frequently. On close examination she notices a grayish, round, and roughened area where the hair has broken off. Examination by the child's pediatrician produces a diagnosis of tinea capitis.

1. Explain the cause of the infection and proposed possible mechanisms for spread of infection in school-age children, particularly during winter months.

2. What methods are commonly used in the diagnosis  superficial fungal infections?

Write a short paragraph (50-100 words) about artificial valves that incorporates all of the following terms: (1) mechanical prosthetic valve, (2) bioprosthesis, (3) homograft, (4) heterograft

58. In cases where members of two species produce an offspring but the offspring is sterile, the type of reproductive barrier is known as which of the following?

a) behavioral isolation             

b) temporal isolation               

c) reduced hybrid fertility

d) reduced hybrid viability      

e) hybrid breakdown

59. In cases where members of two species hybridize but the offspring are weak and unable to compete with non-hybrids, the type of reproductive barrier is known as which of the following?

a) behavioral isolation             

b) temporal isolation               

c) reduced hybrid fertility

d) reduced hybrid viability      

e) hybrid breakdown

60. Female birds typically observe the color pattern and behavior of male birds prior to approaching them to determine their species (prior to assessing them as a potential as a mate). This initial inspection prevents them from hybridizing and is referred to as which of the following?

a) behavioral isolation             

b) temporal isolation               

c) reduced hybrid fertility

d) reduced hybrid viability      

e) hybrid breakdown

In this stickleback system, the red coloration also plays a role in signaling between males and females. Males flash color to females during courtship dances. However, some males do not produce the color. These males adopt cryptic coloration (resembling the background) and engage in sneaky mating attempts instead of courtship. Females do not pay attention to these sneaker males.

63. Which of the following is likely the case for the sneaker males?

a) they outnumber the displaying males and their relative number is maintained by frequency-dependent selection

b) they are outnumbered by displaying males and their relative number is maintained by frequency-dependent selection

c) they outnumber the displaying males and their relative number is maintained by gene flow

d) they are outnumbered by displaying males and their relative number is maintained by gene flow

64. Which of the following is likely the case for females?

a) on average, females benefit more by responding to displaying males only

b) on average, females benefit more by responding to both displaying males and sneaker males

c) on average, females benefit more by responding to sneaker males only

DO YOU SEE WHAT EYE SEE CASE STUDY

1

One of Darwin’s main ideas was that evolution involves descent with modification from common ancestry. We know today that the modification can be simply divergence in gene sequences. The diagram to the right shows a phylogeny for the organisms represented in the sequences above. The degree of similarity in gene sequences is representative of how long ago two organisms have diverged from each other. In other words, organisms with a more recent common ancestor will have a greater similarity in gene sequences than organisms that have a much more ancient common ancestor. Make a hypothesis for which gene sequences listed above represent each branch of the phylogeny.

2

There is variation in nucleotide sequences, but the amino acid sequences for the partial sequence presented in this case are identical between the five species. Explain why natural selection might have favored conservation of the amino acid sequence.

3

How could different nucleotide sequences result in the same amino acid sequences? Explain the mechanism.

4

How is Pax6 and other master genes like HOX different from other genes? How does this difference affect evolution?

Thank you

1. What happens when NMR active nuclei is irradiated with radiowave frequencies ?

The question is from structural biology(NMR spectroscopy).

Consider cargo proteins that are destined for secretion to the extracellular space. Please predict where the cargo will end up (ex. in the cytoplasm, a specific organelle, transport vesicles, multiple places, extracellular space) for: (i) & (ii) Each individual condition; & (iii) The combination of both conditions.

C.

(i) v-SNAREs on COPII coated vesicles are mutated to be unable to bind t-SNAREs

(ii) A transmembrane domain is added to the cargo protein.

(iii) Both
D.

(i) Receptors in the Golgi are mutated so they are unable to bind to cargo proteins.

(ii) COPI coat proteins are mutated so they are unable to bind to membranes.

(iii) Both

8. What are the factors affect the population difference between the lower energy state N sub alpha and the upper energy state N sub beta? How is the population difference is related to NMR signal strength?

The question is from structural biology(NMR Spectroscopy).

Explain how DNA synthesis is used for 3 different methods of base sequencing.

There are several aspects of DNA polymerases that tell you about their probable functions in the cell. These are processivity, 3' -> 5' exonuclease acitvity, requirements for viability, 5' -> 3' exonuclease activity. Describe what each of these mean and indicate what they tell you about the polymerase.