F215 - Revision thread 13th June 2011

"When a plant dies, an animal dies, or an animal expels waste, the initial form of nitrogen is organic. Bacteria, or in some cases, fungi, convert the organic nitrogen within the remains back into ammonium (NH4+), a process called ammonification or mineralization" - Wikipedia

The bacteria/fungi it is talking about are just decomposers

What topics do you think will come up?

Lots of Module 1, about half the paper could be based upon it given the past papers either had alot of Module 1 or alot of Module 2, if pattern follows which it should...as there was hardly any Module 1 in Jan11, but loads in Jun10...

Probably some kind of Gene Genetic Engineering from Module 2

Cloning? Perhaps Insulin, Golden Rice? Sequencing Genomes?

Succession, Conservation

Nervous system PNS - Automatic nervous system

Plant growth hormones, Apical dominance, Auxins

What topics do you think will come up?

If there was a lot of module 1 in june and a lot of module 2 in jan, won't there be a lot of module 3 in this one?
Although you never know with ocr

The process of DNA sequencing:
1. DNA is mechanically sheared into random fragments

2. Microsatellites are used to determine the order of the fragments (location of microsatellites is already known)

3. The fragments are cloned
Fragments are placed into bacterial artificial chromosome
Transferred to E.Coli by transformation
E.Coli are cultured to form a gene library

4. The clones are sequenced using the chain-termination method (Sanger sequencing method)
A very large amount of single stranded DNA is taken from the clone libraries and restriction endonucleases are used to form shorter strands from the long strand
DNA primers, DNA polymerase, normal nucleotides and modified nucleotides that terminate DNA strand elongation are all required for this process
The short DNA strands are divided into 4 separate sequencing reactions, containing all four of the standard nucleotides but only one type of the modified nucleotides
The modified nucleotides lack a 3’OH group, so they terminate formation of the sugar-phosphate backbone
DNA polymerase produces a stand that terminates when a modified nucleotide is added to the end of the chain
Over a period of time, the modified nucleotides form a termination at every point on the strand
The four reactions are separated into four different wells on a gel electrophoresis
Electrophoresis is used to separate the mixtures, producing 4 lanes of different termination nucleotides. The position of modified nucleotides is determined by exposing x-ray film to the electrophoresis gel

5. The chain-termination method is repeated using different restriction endonucleases and the overlapping regions are identified by a computer. The computer assembles the data to form the full genome of the organism

Don't you mean module 4? Unless they're gonna throw in practical techniques, in which case, I'm screwed

whats a punet squared ...?!

I'm actually not sure what I mean
Just that if half the marks in june were from module 1 and half the marks in jan were from module 2, you'd expect them to have half the marks on this paper from module 3, and then from module 4 on the next? I don't know
But I have a feeling succession and galapagos will come up, which are both module 3
Yeah, if anything about investigating populations or quadrats I'm going to kill myself!

Ahh okay, hahah nice I loved the f212 paper in jan, everyone kept saying it was really hard i got a U in f214 in jan though

That's pretty good, especially 67 for a B!
I reallllly want a B overall, so I'd need 105 ums in this, and 65 in my module 4 resit
but i only need a C in biology to get into uni, so that's 75 ums in this module only

the cross diagram you do for finding the genotypes of the offspring

Yo I had an awesome tutor for As level and she had an uncanny ability to predict whats gonna come up in science and maths exams, and as you know OCR love to give you a **** load of information to memorise then only ask you about 10% of the course in the test, or about seals, ****ing seals. Anyway so i gave her a ring last week and she said "gimme a few days to check it out". Anyway she gave me a list of these 12 sections. Keep in mind I could be wrong, but im banking on her being right as she usually is.

1. Lac Operon
2. Apoptosis
3. Chi squared test
4. Hardy Weinberg Equations
5. Differences and similaries between natural and artificial selection
6. Genetic Drift
7. Advantages disadvantages of plant cloning
8. Immobilisation of enzymes
9. Electrophoresis
10. PCR
11. The Brain, structure and so on
12. Dopamine and the DRD4 receptor.

hope that helps

What time are you guys going to sleep today?