OCR Biology F215 Control, Genomes and Environment Fri 15 June 2012

close these are the key words in getting those marks
Natural selection
mutation is random
selection pressure
increase frequency of alleles
over many generation the population would have the CD4 genes

my turn lets ask three at a time is better

Ah! Dang it okay 3 questions

What happens to humans with lack of vitamin D?(2)

Explain the process of transation (5)

Define allele (1)



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1) it can cause rickets and bones break become weaker which leads to abnormalities in legs for example
2)Mrna attaches to ribosomes , trna brings an amino acid and complementary anticodon happens and peptide bonds forms between amino acid. triplet code, trna brings another amino acid due to mrna reading the amino acid and then the chain grows to form polypeptide then a stop codon is reached where the gene no longer codes for an amino acid. An example of a triplet code that stops the prcocess is AUU(i think)
3)An alternative version of a gene present at the same gene loci

Waheyy well done!!!! all correct, but it is not AUU its UAA XD got slightly muddled up theree




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yes thanks i was confused

Ok i am giving you a big fat juicy 10 marker question ok
OUTLINE THE PROCESS OF SEQUENCING OF GENOME (REMEMBER USE TECHNICAL TERMS TO GET THE MARKS! AND YOU WILL BE AWARDED WITH QWC MARKS )

GOOD LUCK

A genome is cut into small fragments. The fragments are inserted into bacteria artificial chromosones. The BAC are inserted into each bacteria. The bacteria divide by binary fission creating colonies of clones each containing the same BAC as its parents. A genomic dna library is formed. The dna is then extracted from each colony, and cut up using restriction enzynes. Then each dna is sequenced using the chain termination method. The peices are put back togetger in order using a highly programmed computer programne from each BCA. and finally the DNA parts from all the BCAS are put back together to complete the genome.



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Cause I remember it from 2 weeks ago but I will finishing revising that chapter today
Hydrolysis refers to removal of water and forming smaller monomers

Immobilised enzymes refers to a technique where the substrate binds with the enzyme and when the products are formed they enter the reaction mixture and the enzyme molecule is ready for accepting another substrate molecule

Yup. Correct for both. And, the plasmid detector is using a marker gene e.g: Fluorescence etc.

hey how are you ok lets revise do you want to do some unit 4 as well
1)why is enzymes in PCR described as thermophilic (1)
2)State 2 differences between PCR and DNA replication (2)

I'm good thanks Just one week before exams!!! Yeah, may as well do Unit 4 and 5 together. It'll be easier.

1) They are capable of withstanding the high temperatures which are used to break the hydrogen bonds in DNA and separate the strands. PCR is accomplished by varying temps significantly therefore require enzymes that can work at optimum at temperatures higher than the usual 37C up to 90C

2) PCR uses primers and restriction enzymes


State the differences between selective and natural pressures? (4)

Define Innate and Latent learning (4)

I'm good thanks Just one week before exams!!! Yeah, may as well do Unit 4 and 5 together. It'll be easier.

1) They are capable of withstanding the high temperatures which are used to break the hydrogen bonds in DNA and separate the strands. PCR is accomplished by varying temps significantly therefore require enzymes that can work at optimum at temperatures higher than the usual 37C up to 90C

2) PCR uses primers and restriction enzymes


State the differences between selective and natural pressures? (4)

Define Innate and Latent learning (4)

hey how are you ok lets revise do you want to do some unit 4 as well
1)why is enzymes in PCR described as thermophilic (1)
2)State 2 differences between PCR and DNA replication (2)

For 2) you could also mention that in DNA replication the enzyme DNA helicase is used to break and make bonds whereas in PCR a cycle of heating and cooling is required.


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Can someone answer this: *

"describe how artificial selection has been used to produce bread wheat (Triticum aestivium)".*

Thank you

dont you talk about like chossing two bread wheat , inbreed and isolation and allow them to breed again to increase number of bread wheat?

I know, I was kind of looking for a "written out" answer that I can learn seeing as its not very clear in the text book. I know what it is but I can never "write it down" to make sense? Have you seen any markschemes on it/got any notes on it?

yes that was weird cause i did not see the writing of it it just shows like the chromosomes number?

No but i will ask my teacher

Yeah, it only has a diagram in the book and I CBa to learn all the wheat names if there's an easier way to explain it. Cool, please quote me when you find the answer