AQA BIOL5 Biology Unit 5 Exam - 22nd June 2011

Just did the specimen paper,some of the questions are so badly worded. I hope that is because its a specimen and not a real paper.

can someone help me out on question 10b specimen paper part b (iii) it says describe the effect of blue light on the growth of seedlings p and q is it something to do with IAA only responding to normal light??? I don't undestand the Mark scheme :/

unit 1= 100
unit 2= 140
unit4=100
unit 5=140

the isas are 60 each methinks!

What does the mark scheme say?

the Mark scheme says for 3 marks you must mention inhibits growth of both in sucrose solution, stimulates growth of both in sucrose and IAA solution. greater effect in P. seedling p is with both root and shoot tipscut off, seedling q is just with roots cut.

Can someone explain the translation stuff in polypeptide synthesis... im really confused :/

Thanks xx

Can someone explain the translation stuff in polypeptide synthesis... im really confused :/

Thanks xx

Hmm I need to see the whole question. I'll have a look at the sample paper and get back to you.

the Mark scheme says for 3 marks you must mention inhibits growth of both in sucrose solution, stimulates growth of both in sucrose and IAA solution. greater effect in P. seedling p is with both root and shoot tipscut off, seedling q is just with roots cut.

This threw me off a bit as well. Basically, what I think it means is that the plasmid you're using for the vector contains the GFP flourescent protein gene. You insert the desired gene into the centre of the GFP gene, so that the GFP gene is non-functional.

Now, in some cases, the vector closes up without incorporating the DNA fragment. If this happens, the GFP gene will be working fine, since the desired gene has not been accepted into it. These bacteria will glow. You do not want these bacteria.

The bacteria whose plasmids have incorporated the desired gene will not have a functioning GFP gene, since the desired gene is in the centre of the GFP gene. In these bacteria, the flourescent protein is not produced, and so these bacteria do not glow.

I think what's confusing about this is that you aren't testing for the bacteria that have successfly taken up the vector That was achieved by growing them on an antibiotic medium. What you are testing for, is those that have taken up faulty vectors that do not contain your gene.

Okay, its a describe question, so all you have to do is describe what the table shows you. The table shows that for the ones grown in just 1% sucrose solution there is a decrease in mean length (so a decrease in growth) when blue light is used as opposed to no light.

But when they're grown in 1% sucrose solution AND with IAA, there is an increase in growth when blue light is used as opposed to no light.

I'm unsure about the last mark. It says the effect of the blue light is greater on P, which you can see happens when IAA is used, but Q has a larger decrease in growth in the 1% sucrose solution.

okie dokie, translation occurs in tge cytoplasm of the cell. it requires ribosomes and the mRNA created in transcription from the nucleus. 1) ribosomes attach to the first set of codons on the mRNA ( codons are the bases of the mRNA). 2) this provides the template for anticodons ( bases on tRNA) to attach to the codons of the mRNA on the ribosomes. 3) ribosomes move up the mRNA strand and attach tRNA as explained before. 4) tRNA has an amino acid molecule at the end of it clover shaped body. 5) when two or more tRNA molecules are next to each other a peptide bond can be formed by condensation reaction using ATP. 4) this continues until it reaches a group of 3 bases on the codon that are called a stop codon this stops the process of translation and polypeptide is finished. hope I've said most of the important points but youshould have a look attempt power point presentation uploaded either on this page or 1/2 back it has some descent points on it

hmmm yeah i should have read the question, I was doing this at 1am so i sort of skimmed the table :P They always have to add a point on the mark scheme were they know no one wil get

what are the things that are not likely to come up on the synoptic essay (because they've come up already)? this is so stressful, i don't know whether to just skim all synoptic stuff and just mainly revise biol5 or go into detail on all the synoptic stuff