Describe in layman's terms how ONE of the following supports evolution by natural selection: the fossil record, the anatomical record, the molecular record. Please use your own words.

What are the costs/risks of overactivation of the immune system?

What does DNA recombination have to do with antibody diversity?

How are T-cells activated?

Can you explain why the amount of force produced by a muscle cell is proportional to intracellular calcium concentration? The number of active crossbridges?

Can you explain the metabolic pathways utilized by slow twitch and fast twitch muscle

fibers generate ATP?

What causes fatigue during muscular activity?

1. In DNA, the type of bonds that form the base pairing between the bases, A::T and C::G are?

a. ionic bonds

b. peptide bonds

c. H-bonds

d. covalent bonds

2. If you wanted to build a short DNA strand, which of the following nucleotides would you not use?

Select one:

a. dTTP

b. dUTP

c. dGTP

d. dCTP

BACKGROUND INFORMATION:

Vinnie is a professional road cyclist participating in the 2020 Giro d’Italia, a three-week race nearly 3,600 km in distance with some stages exceeding altitudes of 2,700 m above sea level (i.e., Stelvio Pass, Italy). As the newly hired head of the high-performance team, it is your responsibility to manage his preparation for the event. You must demonstrate to your team a fundamental understanding of physiology, the chronic adaptations expected from his training, and methods that could be implemented to improve the likelihood of success.

QUESTION:

The longest leg of the race is 228 km, during which energy intake is critical. Glycolysis and β-oxidation are processes that break down carbohydrates (i.e., glucose, sucrose, fructose) and fatty acids, respectively.

A. Individually, what is the total ATP yield from one molecule of glucose and one molecule of palmitate?

B. How did you reach these numbers (i.e., substrate yield and use)?

C. Based on what you know about the yield and speed of these two pathways, do you recommend Vinnie ingest glucose or fatty acids during the race? (Hint, the cross-over concept)

polymer that doesn't have memory

what polymer has no memory

Compare and contrast the structure, life cycle, and host cell type of naked and enveloped viruses.

Describe the ionic basis of an action potential and be sure to include the role of channels/gates within the cell membrane and how this relates to a positive feedback homeostatic mechanism.

1. Antibody is prepared to the thr repressor protein isolated from a wild-type strain.  Competetive antibody binding assays show that several times more repressor is present in an extract prepared from the derepressed mutant described above than in an extract prepared from the wild-type strain.  What is your interpretation of these data?
2. The repressor protein requires a pH of 6.1 for optimal binding to its operator in vitro.  If the pH goes above pH 8.0, the repressor is unable to bind.  What amino acid side chains are implicated?  Why is binding reduced in alkaline media?
3. What effect would an increase in pH have on cell transcription of the thr operon? Why?
4. What percentage of the repressor will bind at pH 6.3?  More than 50% or less?  Now calculate.

What disease present with pinkish rash on hands and feet them arms and legs and fever in children

How does the SOS system simultaneously fix damage DNA and increase the mutation rate? How does the SOS system increase the survival of microorganisms?

Put the events of neural signal transmission at the synapse in the order that they occur from first to last.

First to Last

1.Action potential arrives at synaptic terminal from axon.

2.Vesicles in sending neuron fuse with the membrane.

3.Neurotransmitters are released into the synaptic cleft.

4.Neurotransmitters bind to receptor proteins on the receiving cell membrane.

5.Ion channels in the receiving neuron are stimulated to open.

6.Chance of action potential in the receiving cell either increases or decreases.

1. What is meant by genomic equivalence?

Explain an experiment that supports genomic equivalence by providing functional evidence (Hint: think about what is meant by functional evidence or producing dolly the sheep vs. descriptive evidence like labeling a chromosome and determining different cells in an organisms all have the same chromosome structure). Describe the hypothesis, brief methods, results and conclusion reached.

1. What is the overall message of von Baer’s Laws?

2. Why do you think Darwin was intrigued by these laws (hint: think in terms of continuity and evolution)?

2. During the earliest phases of nervous system development, morphological changes occur and result in the formation of a neural tube.

1. What is the molecular mechanism by which the neural tube physically separates from the epidermis? (Hint: think about differential cell-cell adhesion)

2. Define a “lose it” or loss-of-function technique that would allow you to support that the molecular mechanism above occurs.

3. Describe what is meant by epithelial to mesenchymal transition.

4. During early syncytial specification in Drosophila, bicoid  mRNA localizes to the anterior end of the embryo, where it generates a concentration gradient of the Bicoid morphogen responsible for the development of the head. You perform a chromatin IP experiment to identify new genes that are regulated by the Bicoid transcription factor. You discover Bicoid binds very strongly to the regulatory DNA of a kinase, gene H. It is your job to design a series of experiments to determine if gene H actually functions during head formation of Drosophila.

Briefly describe a strategy for each of the following scientific approaches: (i) find it, (ii) lose it, and (ii) move it (that is, (i) correlation, (ii) requirement, and (iii), sufficiency).

5. It is known that specific signaling pathways promote the development of dorsal structures like the brain and spinal cord. A mutation was discovered in zebrafish that resulted in the duplication of the dorsal side of the embryo (i.e. two heads/brains and spinal cords fused with a shared ventral belly). The loss of function mutation was mapped to the gene Axin, that is, Axin gene function is reduced or removed entirely from the embryo.

1. Which signaling pathway would be affected by the Axin mutation?

2. What is likely to be the effect on Axin loss-of-function on the above signaling pathway (increased or decreased signaling)?

3. Using a reporter gene, how would you test the effect of the axin mutation on the above signaling pathway?

6. Ectopic expression of a gene is forced expression outside of the genes normal domain. In Drosophila, the Gal4 system is used to ectopically express genes in specific places and times.

1. Describe a strategy using the Gal4 system in Drosophila to generate an additional set of eyes in place of the antenna (Hint: think in terms of the ectopic expression an eye master regulator in the antenna domain).  

2. Considering the stages of cell commitment, how might you characterize a cell that initially moves towards an antenna cell fate but then becomes persuaded to be an eye cell? (Hint: think of the environment created by the Gal4 expression system and whether this translates to a neutral or non-neutral developmental context).

7. Dnmts are methyltransferases that function by adding a methyl group to the cytosine of DNA.

1. Describe the importance of DNA methylation to cell identity. How does cell identity play a role in development and maintenance of a tissue?  

2. Explain the connection between DNA methyl and histone methylation?

1. What is an organoid and why are they useful to understanding human development and disease.

2. Briefly describe a strategy where you would use a patient-specific organoid to attempt to understand and cure a disease that you are most interested? (Hint: first think about the disease, then harvesting cells, then creating a useful type of organoid from iPS cells).

1. Describe the mechanism of syncytial specification.  

2. How is it possible that a morphogen gradient of a protein transcription factor can transmit a signal inside the cells of a syncytial embryo?

3. How do morphogen gradients come together to specify regions of the syncytial embryo? (Hint: think about levels of morphogens).

1. What is a stem cell niche? How does a stem cell niche regulate stem cell function?

2. Describe one example of a stem cell niche.

1. What human cell types are pluripotent?

2. Why does harvesting the above pluripotent cells create a moral dilemma?

3. What can be done in the lab to avoid the above moral complications?