Genes & Genomes exam thread

[jinny1]

2010: Q 3 would you say a?
and for Q 9 b or a?
and did we even learn about 19?

2010: Q 3 would you say a?
and for Q 9 b or a?
and did we even learn about 19?

Q3. I thought it was B. initiator tRNA is only for fMet not for all the Met in the codons.
Q9. I picked A but i don't see what's wrong with B either
Q19. I hate these gel electrophoresis questions...I honestly dont think they were covered in our lectures

What did you get for Q42, 47 and 48 on the 2008 exam?

[Starlight]

Q3. I thought it was B. initiator tRNA is only for fMet not for all the Met in the codons.
Q9. I picked A but i don't see what's wrong with B either
Q19. I hate these gel electrophoresis questions...I honestly dont think they were covered in our lectures

What did you get for Q42, 47 and 48 on the 2008 exam?

Sorry jinny1! I haven't covered those questions yet, but having looked at them did we even go over those in our lectures?
I get why you think Q 3 is b, I thought that initially too. However, the quesion is asking about the initiator tRNA which is why I thought it was a. Answer b seems as though the question should be asking "fmet is..." to which I would definitely choose b. I know a can be translated with trnamet though which is why that is confusing me. I think 9b might be wrong because the protein product is trying to reverse the effects of the wild-type, if the mutant protein were inactive then the organism should be showing the wild type phenotype? Lecture notes support a moreso than b. No idea about these gel electrophoresis ones, the one on the 2006 one was the only one I could do.

[jinny1]

Sorry jinny1! I haven't covered those questions yet, but having looked at them did we even go over those in our lectures?
I get why you think Q 3 is b, I thought that initially too. However, the quesion is asking about the initiator tRNA which is why I thought it was a. Answer b seems as though the question should be asking "fmet is..." to which I would definitely choose b. I know a can be translated with trnamet though which is why that is confusing me. I think 9b might be wrong because the protein product is trying to reverse the effects of the wild-type, if the mutant protein were inactive then the organism should be showing the wild type phenotype? Lecture notes support a moreso than b. No idea about these gel electrophoresis ones, the one on the 2006 one was the only one I could do.

I think you are right that the answer is a for Q3. You could argue that b is wrong because initiator tRNA is not a modified form of anything. The amino acid is the one that is being modified. And then a would be correct because the initiator tRNA is not being modified and hence used for all AUG codons in the mRNA. The tRNA is same whether you are using fMet or just normal Met.

I'm pretty sure Q42 in 2008 have been covered so get back to me when you go over them. Q47-48 were probably not covered.

Regarding question 9, answer A is definitely right and answer B is a bit questionable. So i would go with answer A.

[Starlight]

I think you are right that the answer is a for Q3. You could argue that b is wrong because initiator tRNA is not a modified form of anything. The amino acid is the one that is being modified. And then a would be correct because the initiator tRNA is not being modified and hence used for all AUG codons in the mRNA. The tRNA is same whether you are using fMet or just normal Met.

I'm pretty sure Q42 in 2008 have been covered so get back to me when you go over them. Q47-48 were probably not covered.

Regarding question 9, answer A is definitely right and answer B is a bit questionable. So i would go with answer A.

Cool!
I shall get back to you on the questions you have mentioned, it might be the day before the exam though.. :S

[Starlight]

2008 21c?
and absolutely no idea about q42 (maybe c? makes up the 13kb ecor1 fragment but no clue)
2010 q 24? Thought either a or c, I think c more though..
Ugh and I also hate the restriction map ones like 39 in 2010

[jinny1]

2008 21c?
and absolutely no idea about q42 (maybe c? makes up the 13kb ecor1 fragment but no clue)
2010 q 24? Thought either a or c, I think c more though..
Ugh and I also hate the restriction map ones like 39 in 2010

2008 Q21. I thought D. Isn't CAU a histidine?

I'm clueless at the southern blot diagram questions lol

2010.Q24. I chose A because it is obviously unlinked to ValA looking at the recombinants and C doesn't sound right.

Yea basically the only questions i have problems with are the ones with diagrams...Probably because these are practical applied questions and in lectures we learn the theory component.

[Starlight]

2008 Q21. I thought D. Isn't CAU a histidine?

I'm clueless at the southern blot diagram questions lol

2010.Q24. I chose A because it is obviously unlinked to ValA looking at the recombinants and C doesn't sound right.

Yea basically the only questions i have problems with are the ones with diagrams...Probably because these are practical applied questions and in lectures we learn the theory component.

Hey RE Q21. CAU= the anticodon I think. It helps to use the polarity. 5'CAU3' the anticodon and the complementary mrna codon is 3'GUA5' which is read, but we recognize it in the form of 5'AUG3' (the reverse) and this codes for methionine. The wild-type 5'GAU3'= 3'CUA5' mrna codon which is read= 5'AUC3' and this codes for isoleucine. So I think there is a change of isoleucine-> methionine. Unsure if it would be a or c in this case. I was thinking C because the missense mutation should probably just occur to one mrna codon and not two as in a?

Do you also think Q 39 from 2008 is c?
RE your questions 42,47,48- I've never been good at restriction maps so i'm just going to have to guess C for that one! As for 47 I think it's covered in the RFLP lecture by john and I chose d. I was unsure about question 48 but obviously eliminated d. I don't think it's b because the mutation should decrease ethanol tolerance.. Maybe a? What do you think?

Also q 27 (2010)= a?

[jinny1]

Hey RE Q21. CAU= the anticodon I think. It helps to use the polarity. 5'CAU3' the anticodon and the complementary mrna codon is 3'GUA5' which is read, but we recognize it in the form of 5'AUG3' (the reverse) and this codes for methionine. The wild-type 5'GAU3'= 3'CUA5' mrna codon which is read= 5'AUC3' and this codes for isoleucine. So I think there is a change of isoleucine-> methionine. Unsure if it would be a or c in this case. I was thinking C because the missense mutation should probably just occur to one mrna codon and not two as in a?

Thanks for clarifying that. I think the answer would then be C too. The question states a single mutation not multiple mutations.

Do you also think Q 39 from 2008 is c?

I chose D becuase both Pst and Sac seem to have lost 2kb fragments.

RE your questions 42,47,48- I've never been good at restriction maps so i'm just going to have to guess C for that one! As for 47 I think it's covered in the RFLP lecture by john and I chose d. I was unsure about question 48 but obviously eliminated d. I don't think it's b because the mutation should decrease ethanol tolerance.. Maybe a? What do you think?

For Q48. i might as well blind pick lol i have no idea :S

Also q 27 (2010)= a?

I chose C. It would create what the questions asks given that the lethality is recessive not dominant.

Good luck with exam tomorrow

edit: what did you get for Q27, 2008 exam?

[Starlight]

Ah yes I agree with everything that you've said, looks like I rushed those questions.

RE Q 27(2010) I chose a I found something like that on the internet

[Starlight]

Thanks, good luck to you too!