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Should we know a little about conservative and dispersive replication?

butter side up wrote:

reichenbach wrote:Hi! I'm new to this event and I had a question about the genotype ratios:

How do you know how to order the genotypes when writing the genotype ratio? Does it matter if you label everything?

For example, if the genotype is 1 D/D: 2 D/H: 1 D/R: 4 H/H: 4 H/D: 1 R/D: 2 R/H: 1 R/R, would it matter if you wrote it as 2 D/H: 1 D/D: 1 D/R: 4 H/H: 4 H/D: 2 R/H: 1 R/D: 1 R/R?

Thanks so much in advance for your help!

[I'm assuming you're referring to a cross with two traits here, with D as homozygous dominant, H as heterozygous, and R being recessive?]

I'm pretty sure that at least tradition (possibly also a rule) dictates that it goes in the order
DD:DH:DR:HD:HH:HR:RD:RH:RR

Such that a standard cross between two heterozygous individuals (AaBb x AaBb) would result in the ratio
1:2:1:2:4:2:1:2:1

[Also- I like the username, even if it did nearly cause me to go on a rant in the middle of the library. Violently in need of that elusive creature Season 3.]

Thanks again! That's exactly what i meant.

And I'm assuming the phenotype ratio would be expressed as DD:DR:RD:RR?

Cedavis6 wrote:Should we know a little about conservative and dispersive replication?

I would study the Meselson–Stahl experiment and the hypotheses behind it. It's not that much information

reichenbach wrote:And I'm assuming the phenotype ratio would be expressed as DD:DR:RD:RR?

Yep, exactly!

2000lby wrote:

Cedavis6 wrote:Should we know a little about conservative and dispersive replication?

I would study the Meselson–Stahl experiment and the hypotheses behind it. It's not that much information

And other than knowing that conservative and dispersive replication have been discredited as theories, I wouldn't devote much attention to it. I'd focus more on understanding the mechanisms of semi-conservative replication, which has been supported. And a basic comprehension of the Meselson-Stahl experiment is probably a good idea- at least the rudiments. It isn't too complicated, and it follows many of the procedures that are used in other genetic experiments.

YUSH! I got 1st place in my Heredity tryouts! Thanks, butter side up Now to beat all my competitors for Forestry and Food Science.

THANK YOU to whoever uploaded the Wright State tests!

On question 10 of station 2, "Would the protein produced from this mRNA sequence change if the A indicated by * is changed to U? If yes, indicate how," the answer key says, "Point mutation from Lys to Asn; all others remain unchanged." It seems similar to the example in the rules, "Which DNA sequence would result in a different amino acid sequence?"

For that question on the Wright State test, we knew it would be a point mutation and that all others would be unchanged. Is it good enough to just put that down as the answer, or should we include a key in our notes as to which triplet codes for which amino acid, so that we can tell whether it is silent or not, and what the new acid would be?

deezee wrote:Do any of you know any good resources where we can find info on DNA sequencing, protein synthesis, and stuff like that? I'm guessing a lot of the stuff on the tests will include AP bio knowledge (which i haven't even taken yet... =.=)

My coach owns an online copy of the Campbell Bio book that I use for that kind of stuff. Not quite sure how much it costs, probably overly expensive

Slarik wrote:THANK YOU to whoever uploaded the Wright State tests!

On question 10 of station 2, "Would the protein produced from this mRNA sequence change if the A indicated by * is changed to U? If yes, indicate how," the answer key says, "Point mutation from Lys to Asn; all others remain unchanged." It seems similar to the example in the rules, "Which DNA sequence would result in a different amino acid sequence?"

For that question on the Wright State test, we knew it would be a point mutation and that all others would be unchanged. Is it good enough to just put that down as the answer, or should we include a key in our notes as to which triplet codes for which amino acid, so that we can tell whether it is silent or not, and what the new acid would be?

I would include a chart for checking triplet codes on your cheat sheet. I'm pretty certain that it will be important for tests- I have seen it as necessary before. You can find some very compact ones, especially if you are already familiar with the abbreviations used for amino acids *cough Protein Modeling cough*, so it shouldn't take up too much space on your sheet. Many times the specificity that comes with that can be an extra point or two which can make loads of difference in some tests.

butter side up wrote: I would include a chart for checking triplet codes on your cheat sheet. I'm pretty certain that it will be important for tests- I have seen it as necessary before. You can find some very compact ones, especially if you are already familiar with the abbreviations used for amino acids *cough Protein Modeling cough*, so it shouldn't take up too much space on your sheet. Many times the specificity that comes with that can be an extra point or two which can make loads of difference in some tests.

Alright, thanks. It seems like they should give you a table if you need it, but I was leaning the same way as you after taking the Wright State test.

Does anyone have a Division B test?