Which of these is true about secondary contact?

A. Hybrids are always infertile.

B. Hybridization can result in new species.

C. Hybrids typically resemble neither parent species.

D. Reinforcement can decrease differences between parent species.

Brown headed cowbirds lay their eggs in other birds’ nests, a behavior called nest parasitism. When this strategy succeeds, the host birds accept the cowbird egg as one of their own and rear the cowbird chick. When it fails, the host birds reject the cowbird egg as an imposter and remove it from the nest. Why do any host species accept cowbird eggs in their nests? This seems maladaptive since they are expending energy that should go toward raising their own offspring on cowbird chicks. Biologists have proposed two hypotheses: first that the parasitized species have not yet evolved the behavioral response of egg ejection yet, but eventually will. The second hypothesis is that the host birds are physically constrained since their beaks are too small to remove the large cowbird eggs from their nests.

Propose an experiment to determine which of these two hypotheses is correct.

Describe telomeres and how they contribute to genome stability in human cells. Discuss their roles in the maintenance of the genetic information.

Essay include diagrams

Using one repair pathway as an example provide a detailed description of the mechanism of excision repair, and explain the importance of excision repair in maintaining genome stability. Essay style please include diagrams

. Discuss how a blockage in the mitochondrial apoptotic pathway can lead to an alternative, autophagy-mediated death programme, during cell stress. essay style include diagrams.

Evaluate the roles that long non-coding RNAs (lncRNAs) play in epigenetic processes such as imprinting and X chromosome inactivation. Essay style

L. Scott Mills and his colleagues examined the seasonal coat color change in snowshoe hares. Snowshoe hares are typically brown in the summer and white in the winter. They argue that a mismatch between coat color and the environment can be a big problem for these important prey animals. Answer each question in 2-6 sentences (not only “Yes” or “No” - provide examples/arguments supporting your response). Always write in your own words

1. Will snowshoe hares be able to alter their seasonal coat color change if the climate changes? What drives local adaptations? Speculate about two alternative trajectories.

Contrast properties of an epithelial tissue with those of a mesenchymal tissue. How are cadherins related to the transition of epithelium to mesenchyme; How is this transition regulated or triggered?

Two genes, A/a and B/b, control fruit color in squash. The inheritance pattern for this trait fits one of the multiple gene types that we discussed in class. A homozygous plant with white fruit was crossed with a homozygous plant with yellow fruit. All the progeny had red fruit. When two F1 plants were crossed, the F2 consisted of 38 white, 27 yellow, and 89 red.

(a) (2 pts) Which type of gene interaction do we see here? Explain your reasoning.

(b) (2 pts) What is the expected ratio of white to yellow to red fruit in the F2?

(c) (3 pts) What were the genotypes of the P generation plants?

(d) (5 pts) Test your hypothesized gene interaction model with Chi-square analysis. Please include all the components of Chi-square analysis in your answer.

(Continues on the back…)

(e) (5 pts) The diagram explains how the two genes interact at the molecular level. Compounds X, Y, and Z determine fruit color depending on which of the two chemical reactions occur. Each gene produces an enzyme that is either active or inactive depending on its genotype.

When an enzyme is active, the reaction it catalyzes occurs; when it is inactive, the reaction is blocked. Write in the boxes the genotypes that would explain the inheritance pattern.

(2 pts) Please fill in the box with the according genotypes.

(3 pts) Interpret the pathway with your own words (e.x. how to read this pathway? how you get white, yellow and red colors from different genotypes by following this pathway graph? Circle out the epistatic genotype in your pathway)

1. How does gene expression initiate?

2. What are the key steps in gene expression?

1. hat is the immediate consequence after electrons pass through ion pump protein?

2. How is the proton concentration gradient created inside and outside of mitochondrial inner membrane?

3. ATP is produced due to the electron transport or due to the proton gradients.

4. How many ATP can be produced when every three hydrogen ions pass through ATP synthase?