Multiple Choice - HW - (Nov/04/2006 )

Can anyone help me with the following questions?
we can also discuss them - thanks

PS: Questions are attached

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at keast may you give your supposed answers?

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1.b. should be used in about equal molar amounts to each other

2.d. All of the above

3. c. Exponential amplification in the presence of dideoxynucleotides

4.a. Requires incorporation of dideoxynucleotides

5.d. All of the above

6. b. The function of most human genes

7.a. Gene isolation

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6. Deciphering the sequence of the human genome has provided which of the following information?

a. A rough estimate of the number of disease genes

b. The function of most human genes

c. An explanation to different drug responses of patients

d. None of the above


I would argue the answer is d: None of the above. A sequence doesn't tell you much. It hints at the structure... (and high eukaryote genes are notorious for having multiple isoforms.) but a structure doesn't really tell you what exactly it does. You still need to find that out.

And a mouse genetisis will tell you most genes don't seem to do anything. Knock them out and the mouse is fine. There are multiple redundancies. Yet not all redundant pathways in a system are exactly the same. And some gene only show their effects under very specific conditions.

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the DNA sequence does not tell you the function. it doesn't tell you which genes are involved in disease. it does not tell you which patients will react to what drugs, etc. but knowing the sequence of genes you can begin to investigate the above three things. so, the answer for that question is none of the above.

question 5... FISH definately, STS definately... haven't heard of genetical mapping... but through the process of elimation, the answer would have to be all of the above.

question 4... sanger sequencing involves 2',3'-dideoxynucleotide triphospates (ddNTPs), molecules that differ from deoxynucleotides by the having a hydrogen atom attached to the 3' carbon rather than an OH group...

and i have to go back to work now
V

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pity your replies were after i submitted my HW as i got this one wrong - thanks a lot for your help - your great

i have another set of multiple choice if you want to help me - i have to submit this by this Sunday evening

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Hi helicase00,

Would you please give us your answers to the MCQ?
Then we can tell you whether the answers are correct or not.

Minnie Mouse

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1) d. Are used for positional cloning
2) d. All of the above
3) b. Is often performed ex vivo
4) d. Gene therapy
5) c. Deamination
6) b. Transversion
7) c. For cancer to develop, both copies of a particular gene must be mutated.
8) d. Both were correct since most chemical carcinogens function by altering genes.

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1 : i'm in doubt, but i'm quite sure that in vivo recombination si not possible in mammals as in yeasts. There was a method developped by Vogelstein (NAR) for easy knock out, but not homologous recombinatios. Cre lox system which is a recombination (Cre recombinase) is not an homologous recombination.

2) i get dizzy with that quesiton.
If d if the correct answer, then other should be wrong too.
In contrary, if D is correct, all are correct... so get in opposite of the subject.

3) c i think that human gene therapy is a great hope, but just few diseases have been cured

4) d

5 )C it's an oxydative deamination.

6) b UV causes dimers thymine to appear

7) c

8d

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got no 6 wrong - correct answer is c - Thymine Dimers

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