1.    What is the significance of metanephridium thickness in the earthworm? Be specific.

2.    Compare and contrast the exoskeleton of the grasshopper and the crayfish. How might they be used differently for osmoregulation?

3.    The green gland of lobsters does not have any convoluted tubules associated with it as it does with the crayfish. What might be the significance of this difference?

In July 2000, the Protein Data Bank named the nucleosome “molecule of the month.” In an accompanying report, David Goodsell wrote that

"The job of the nucleosome is paradoxical, requiring it to perform two oppo- site functions simultaneously. On one hand, nucleosomes must be stable, forming tight, sheltering structures that compact the DNA and keep it from harm. On the other hand, nucleosomes must be labile enough to allow the information in the DNA to be used. Polymerases must be allowed access to the DNA, both to transcribe messenger RNA for building new proteins and to replicate the DNA when the cell divides."

Explain how nucleosomes help DNA to adopt a highly-compact structure while also keeping the DNA molecule accessible for transcription and replication?

a part of a membrane at rest showing the transport of glucose using the glucose-Na+ symport protein. We know that the average mammalian cell has a cytosol chemical concentration of roughly 15mM of Na+ as compared to its extracellular concentration of 154 mM. Overall, the electrical gradient in cells at rest are more negative inside as compared to outside of the cell.

1.There is strong electrochemical gradient for Na+, explain why this is true (hint, think about what makes up the electrochemical gradient).

2.The ion, chloride (Cl-) is more concentrated on the outside (110 mM) than the inside of the cell (15 mM). Do you expect the overall electrochemical gradient for chloride to be as large as the Na+ electrochemical gradient? Explain why or why not (hint, think about what makes up the electrochemical gradient).

3.If the concentration of Na+ increased on the inside of the cell so that it was equal on both sides, would we see an increase or decrease in the overall electrochemical gradient of Na+ as compared to the resting cell? Explain your answer

4.The glucose-Na+ symport protein uses the electrochemical gradient of Na+ to move glucose against its concentration gradient. Predict whether the transport of glucose from the extracellular side into the cytosol would increase or decrease under the following scenarios:

a.The Na+ electrochemical gradient is greatly reduced.

b. A ligand binds to the symport protein so that the site which binds Na+ no longer has a strong affinity for Na+.

the Na+ K+ ATPase pump, also known as the Na+ pump. This pump moves both Na+ and K+ against their concentration gradients through the hydrolysis of ATP (here is another way, ATP, the “currency of the cell” is used).

5. Compare and contrast the properties and the functioning of these two types of transporters.

Why is it so important that blood glucose levels be maintained within a narrow range? what is bad about having too much or too little glucose in the blood? How are insulin and glucagon involved in regulating the concentration of glucose in the blood?

The purpose of the lysis procedure is:

to sequence the 16S rRNA gene

to separate the pieces of nucleic acid from one another

to break open the bacterial cells to release the genetic material

to amplify the 16S rRNA gene

Match the components of HotShot buffer with their role.

NaOH    

            removes anions so they cannot be used as cofactors by enzymes, increases pH to denature nucleases, disrupts lipid membranes, removes cations so they cannot be used as cofactors by enzymes, or decreases pH to denature nucleases

Detergent

            removes anions so they cannot be used as cofactors by enzymes, increases pH to denature nucleases, disrupts lipid membranes, removes cations so they cannot be used as cofactors by enzymes, or decreases pH to denature nucleases

Chelator

             (removes cations so they cannot be used as cofactors by enzymes)

When taking some of your bacterial isolate to place in the HotShot buffer you should take as much as can fit on the end of the pipette tip.

True OR False

The role of neutralization buffer is to:

restore the pH to approximately neutral

increase the pH to 10

introduce nucleases into the reaction

decrease the pH to 3

Nuclease-free water is added to the reaction mix to _____________________. Choose all that apply.

increase the volume of the solution without introducing nucleases which could degrade the nucleic acids

dilute the lysate so it is not too concentrated for later procedures

to stop the chemical reactions occuring in the solution

add nucleases to the reaction mix

Where do you see our species going in the future? Is "building" humans through genetic modification the right thing to do?

IV. FILL-IN QUESTIONS

1. German measles is a relatively mild disease but can cause severe fetal defects in

     35% of cases when a pregnant woman is infected during the first trimester. This

     condition is called ____________________________________________.     

2. In order to confirm the diagnosis of tuberculosis, a patient must test positive in three

     different tests. They are the __________________________________________,

     _______________________________, _________________________________.

3. A severe enteric infection that takes 2-3 weeks to disseminate throughout the body

     causing a high fever, an unremitting headache and diarrhea is responsible for

     500,000 deaths worldwide, but very few cases in the U.S. This disease is

     ________________________________ and is caused by ____________________

     _____________________________ .

4. The _______________ test is used in diagnosing vaginosis, due to a frothy discharge

     that has a fishy odor which is the result of certain amines being produced.    

1. What are the causes of the common cold?
2. How does a virus cause a disease?

Scenario: Recently, Jon Doe suffered a serious neck injury in which his spinal cord was damaged and will not heal without stem cells. Doctors say, due to his highly unusual genetic make-up, it is almost impossible that they will ever find usable and compatible donor cells. Jon Doe’s family is looking into new methods to find something to help him. Consider what we have covered with regard to stem cells. Explain a way in which doctors could use stem cells that are a perfect match to Jon Doe's DNA (regardless of how complex his ethnic background is.) Be sure to use appropriate vocabulary in your justification of your response. Note: Human cloning is illegal and therefore cannot be used as an answer here.

Apply a rule and determine which of the following populations are in Hardy-Weinberg equilibrium. Show your work.

Genotypes
AA Aa. aa
Population I .430 .481 .089
Population II .64 .32 .04
Population III .25 .50 .25

a. Is population I in equilibrium

b. Is population II in equilibrium

c. Is population III in equilibrium

The “Skinny Bacteria” research company has generated a synthetic chemical called "WPT" that binds to LacR and causes a shift in its structure.

Provide a written description for what you think will happen to cellular levels of LacZ if WPT is added to the bacterial growth environment.

Describe three classes of spindle microtubules including their functions, locations, and the polarity:

o Aster microtubules

o Kinetochore microtubules

o Interpolar microtubules