In the experiment by Otto Loewi, stimulation of the vagus nerve caused an isolated frog's heart to slow its beating (an effect called bradycardia). This effect was ultimately shown by others to be due to the release of acetylcholine (ACh) from vagus axon terminals at synapses with cardiac muscle. However, Loewi also showed that the solution bathing this heart, rich with ACh released from the stimulated nerve axons, could be used to cause bradycardia in a 2nd heart, without direct vagus nerve stimulation. Indeed, we can replicate this by spritzing ACh directly onto a beating heart, again without vagus nerve stimulation.

So, how is it possible for a neurotransmitter like ACh to exert its effects on a target without being released presynaptically at a particular synapse? What does this say about the contribution of neurotransmitter degradation/reuptake to the precision and integrity of neurotransmission?

1. Supplementary motor cortex
2. Premotor cortex
3. Basal ganglia
4. Cerebellum
5. Parietal area of the cerebral cortex
6. Spinothalamic pathway
7. Corticospinal tract
8. Dorsal root ganglion
9. Dorsal Column pathway
Q1. Which structure or region is damaged in patients with Parkinson’s disease?
Answer 1Choose...1.2.3.4.5.6.7.8.9.
Q2. Which structure or region includes the cell bodies of sensory neurons?
Answer 2Choose...1.2.3.4.5.6.7.8.9.
Q3. Which structure or region conveys information from the brain to the spinal cord?
Answer 3Choose...1.2.3.4.5.6.7.8.9.
Q4. Which structure or region is damaged in patients with Huntington’s disease?
Answer 4Choose...1.2.3.4.5.6.7.8.9.
Q5. Which structure or region that is not part of the cerebral cortex is involved in initiating complex movements?
Answer 5Choose...1.2.3.4.5.6.7.8.9.
Q6. Which structure or region handles information from pain receptors?1.2.3.4.5.6.7.8.9.

Write a full description of the importance and different types of fermentation carried out by bacteria.

For a diploid mouse cell (40 chromosomes), state how many copies of each are present at the following cell cycle stages:

A researcher has synchronized two different E. coli cultures so that all of the cells enter cell division simultaneously. One culture is wild-type E. coli cells, and the other culture is a mutant E. coli that does not have the gene for Dam methylase. He isolates the DNA from both wild-type and mutant E. coli 20 minutes after replication is complete. What is the methylation state for each strain of E. coli? What would be the methylation state for each bacterial strain if you isolated the DNA immediately after replication termination?

Red-green color blindness is caused by a mutation in a gene on the X chromosome. X^a is the recessive mutant allele that causes color blindness; X^A is the dominant, functional allele. You meet a patient who has Klinefelter syndrome (that is, he has an XXY karyotype). His mother is color blind, but his father has normal color vision. Your patient has both the X^A and the X^a alleles.

1. You hypothesize that your patient’s syndrome is due to a meiotic nondisjunction event that occurred in: (circle the correct options) (2 pts)

this patient                this patient’s father              this patient’s mother

                                                Meiosis I         or        Meiosis II

2. In the space provided below, illustrate how the meiotic nondisjunction event occurred, showing only the sex chromosomes. If you think it could happen in either meiosis I or II, pick one of these for illustration. (6 pts)

1. Use the symbols below to illustrate the X and Y chromosomes:
2. Use arrow(s) to indicate the cell(s) that could give rise to your patient’s abnormal karyotype.

3. You also find a small number of cells in this patient with only one X and one Y chromosome. Explain this phenomenon in no more than two sentences. Be specific about in which individual and roughly when this relevant event might have taken place. (2 pts)

Describe the fate of a single molecule of glucose as it goes through glycolysis and exits the Krebs cycle. Include the inputs to each reaction and all end products including all created energy storage molecules.

Molecular dynamic simulation of protein- ligand complex.
How do I set up a molecular dynamic simulation for a protein- ligand complex with a cobalt in the 2++ state? In other words, are there topology and parameter files that contain parameter for cobalt ion which are compatible with NAMD?

Describe the ways in which meiosis contributes to genetic diversity within a population in which 2n=20.

3. Assume that a bacterial culture is grown on medium containing radioactive thymine until essentially all of the thymine in the DNA is radioactive. Then the bacteria with labeled T were washed and transferred to a medium containing nonradioactive T for one round of replication. Given the four double stranded sequences below, which one is likely to represent the replicated double stranded structure? Note: A,C,T,G represent typical nucleotides, and 3T represents labeled T.)

In PCR reactions, the only enzyme that is needed is a polymerase. Provide reasoning as to why the following essential replication enzymes/components are not needed:

Helicase

Topoisomerase

Ligase

Primase

Replication clamp

Compare and contrast the process of substrate-level phosphorylation, oxidative phosphorylation, and photophosphorylation. Provide one example of how each is used in a biological cell.

You isolate nuclei from three different eukaryotic species. You treat the samples in exactly the same way (adding same amount of enzyme, buffer and time) to partially digest the chromatin with micrococcal nuclease, extract the DNA, and run it on a gel. You see the pattern below:

a-2pts) Knowing that the core-DNA in all cell types is the same what is your explanation for the difference in size in the patterns you observe (shown below):

b- 2pts) If you digested each of the three samples more thoroughly, what would the pattern look like? [Be specific and indicate what the size of the bands would be]

c-3pt) An explorer discovers a strange new species of plant and sends some of the plant tissue to a geneticist to study. The geneticist performs the kinds of experiments as described above in (b) except that: After digestion with nuclease 120-bp fragment of DNA are seen.
Analysis of the histone core reveals histones in the following proportions:

H2A 33.3%
H2B 33.3%
H3 0% [no histone H3 found]

H4 33.3%

On the basis of these observations, what conclusions could the geneticist make about the probable structure of the nucleosome in the chromatin of this plant? Be specific in describing the nature of the nucleosome: which histones form the core (1pt), how many of each are in there (1pt) and how much core-DNA is around it (1pt).

d-2pt) The geneticist also found H1 and a new histone H7 when histones were extracted from all of the chromatin (not just the nucleosome). What do you think the role of the new histone H7 would be in this new plant species?

what are the steps you will take to isolate and identify a salmonella sp.

Compare and contrast the chromosome structure of viruses, bacteria, and eukaryotes.

Regarding the mitotic cell cycle, what is meant by a checkpoint?

1. What are 3 ways by which bacteria can overcome, evade or avoid phagocytosis? 3pts

2. Some bacteria can stop the activation of complement. Suggest 2 things bacteria might do to complement proteins to stop or prevent complement activation. Describe how stopping complement activation would protect the bacteria. 4pts

3. Explain how CD8, CD4 and B cells work together either in the lymphoid tissue OR at the site of infection.