[sumsum123]

(Original post by Sparkzz)
hmm ok thanks!
1) point mutation (substitutions)
2) insertion/deletion (frameshift)
3) stutter

anymore :/

1) What is genetic drift?
2) What changes allele frequencies in changing conditions?
3) What affect does inhibitory RNA have on mRNA?

Those are correct dna mutations but I asked for chromosome mutation. So that would be non-disjunction, inversion, translocation and deletion. I dont know whether you have to know that but it is in the textbook, pg 121.

1) Genetic drift is the change in allele frequency due to random chance over time.
2) I dont really know er selection pressures increase certain allele frequences in changing environments
3) It can anneal to the mRNA and make a double stranded RNA which the ribosomes cant read. The double stranded RNA then gets destroyed this stops protein synthesis. Erm correct me if I am wrong

Describe what happens during apopstasis

[Sparkzz]

(Original post by sumsum123)
Those are correct dna mutations but I asked for chromosome mutation. So that would be non-disjunction, inversion, translocation and deletion. I dont know whether you have to know that but it is in the textbook, pg 121.

1) Genetic drift is the change in allele frequency due to random chance over time.
2) I dont really know er selection pressures increase certain allele frequences in changing environments
3) It can anneal to the mRNA and make a double stranded RNA which the ribosomes cant read. The double stranded RNA then gets destroyed this stops protein synthesis. Erm correct me if I am wrong

Describe what happens during apopstasis

ahh yes!

and for 2) its a directional pressure that changes allele frequencies

do you mean apoptosis?
if so then apoptosis is controlled cell death occuring in these steps:
1) enzymes break down cytoskeleton
2) cytoplasm becomes dense as organelles become tightly packed
3) chromatin condenses and nuclear envelope breaks down, dna breaks into fragments, and blebs form
4) vesicles containing organelles are taken up by phagocytes


1) Define ecosystems.
2) Explain why the hardy-weinburg principle is not used for codominant alleles?
3) Define genetic code.

(if i fall asleep we shall continue tommorow lol)

[sumsum123]

(Original post by Sparkzz)
ahh yes!

and for 2) its a directional pressure that changes allele frequencies

do you mean apoptosis?
if so then apoptosis is controlled cell death occuring in these steps:
1) enzymes break down cytoskeleton
2) cytoplasm becomes dense as organelles become tightly packed
3) chromatin condenses and nuclear envelope breaks down, dna breaks into fragments, and blebs form
4) vesicles containing organelles are taken up by phagocytes


1) Define ecosystems.
2) Explain why the hardy-weinburg principle is not used for codominant alleles?
3) Define genetic code.

(if i fall asleep we shall continue tommorow lol)

Yes I did I was sleepy aha. And thats correct.

1) An ecosystem is a group of living organisms and non living things occuring together and the interrelationship between them
2) dont know how to explain it. I know you use the hardy weinberg when one of the alleles ate recessive because the heterozygotes and dominant homozygotes show the same phenotype. Erm yerh can you tell me please
3) it is the sequence of nucleotide bases on a gene which provides information for making polypeptides. It is arranged in groups of three.

Describe a method when using quadrats to achieve random sampling

[--NWzD9--]

Does anyone have or know where to get the F215 January 2012 paper from, and the mark scheme?

[jwells]

F215_MS_Jan12.pdfF215-01Jan12.pdf

(Original post by --NWzD9--)
Does anyone have or know where to get the F215 January 2012 paper from, and the mark scheme?

[ManPowa]

(Original post by jwells)
F215_MS_Jan12.pdfF215-01Jan12.pdf

http://www.thestudentroom.co.uk/show....php?t=1943168

All the Bio n chem jan 12 papers are here

[Sparkzz]

(Original post by sumsum123)
Yes I did I was sleepy aha. And thats correct.

1) An ecosystem is a group of living organisms and non living things occuring together and the interrelationship between them
2) dont know how to explain it. I know you use the hardy weinberg when one of the alleles ate recessive because the heterozygotes and dominant homozygotes show the same phenotype. Erm yerh can you tell me please
3) it is the sequence of nucleotide bases on a gene which provides information for making polypeptides. It is arranged in groups of three.

Describe a method when using quadrats to achieve random sampling

sorry for the late reply, been busy all day
anyways to continue

2) For codominant alleles, the genotypes and phenotypes are known
3) Yes but also say that it is degenerate (amino acids have more than one code), the triplet codes are widespread and not universal, and some indicate a stop sequence.. (usually 3 marks)

I have no idea
Determine random numbers and randomly place the quadrat square during regular intervals in the habitat. Count the abundance (individuals of each species) in each square and calculate the percentage cover?

[Sparkzz]

(Original post by sumsum123)
Yes I did I was sleepy aha. And thats correct.

1) An ecosystem is a group of living organisms and non living things occuring together and the interrelationship between them
2) dont know how to explain it. I know you use the hardy weinberg when one of the alleles ate recessive because the heterozygotes and dominant homozygotes show the same phenotype. Erm yerh can you tell me please
3) it is the sequence of nucleotide bases on a gene which provides information for making polypeptides. It is arranged in groups of three.

Describe a method when using quadrats to achieve random sampling

1) Define homeobox genes and hox clusters
2) If glucose and lactose concentrations were equal in a medium containing E.coli, suggest how the bacterium decides to use lactose as a respiratory substrate instead of glucose?

seconds ones abit weird lol

[Groat]

How many of you here have got to do F214 as well?

[Sparkzz]

(Original post by Groat)
How many of you here have got to do F214 as well?

I amm

[im so fresh]

(Original post by Groat)
How many of you here have got to do F214 as well?

sadly.
Got 54 the first time. Didn't take it seriously :/
I really need 75 in it.

[UKnowWhoYouAre]

Does any one have predictions what might come up?

[rainbow_kisses]

(Original post by UKnowWhoYouAre)
Does any one have predictions what might come up?

This is a very very risky strategy.

[Sparkzz]

(Original post by UKnowWhoYouAre)
Does any one have predictions what might come up?

just read pages 104-247 and you should be fine

[Fatima0065]

Can anyone tell me the point for both Trancription and Translation that will get full marks if a question comes up. Bullet points please. Thankyou

[Fatima0065]

(Original post by sumsum123)
Genetic drift is the change in allele frequency by chance, just random. The difference between genetic drift and natural selection is in natural selection certain alleles could be more advantagous to the organism so those would be selected in order to be passed on to the offspring. However with genetic drift, the increase or decrease in different alleles is not so much due to it being more advantagous. Random example, if you have 10 green worms and 10 orange worms, 5 green worms could be killed and 2 other green ones cant have young. So that leaves you with 3 green worms and 10 orange worms. The allele frequency has decreased for the green coloured worm, after a couple of generation perhaps you wont even find any green worms. That is the general idea , correct me if I am wrong.

Thanks..i kind of undestand it... Basically..genetic drift is the change in allele frequency by chance??? and btw you really clever!! , how ddo you revise?

[Rachel U]

Hey guys,
I just thought that I would give you tell you some things that I used for revision when I did my Chemistry and Biology A levels last year in case you wanted some tips.

I know everyone condemns them but CGP revision guides were my life literally. Use them to get a basic understanding of the chapters and which can then be expanded on by reading through the textbook/going to lessons. I made notes from it all the time and then went through and answered the questions at the bottom of each page separately to test myself then answered the end of chapter questions in the textbook and lastly did tons of past papers.

The past papers were particularly helpful because the mark schemes gave you the main points of what you needed to include in your answer to get the marks, preventing you from waffling (waste of time).

So yeah, that was my revision technique to rinse, lather, repeat. I got 85% for both Bio and Chem so it must work to an extent, just see if its right for you

Good luck!

[sumsum123]

(Original post by Sparkzz)
sorry for the late reply, been busy all day
anyways to continue

2) For codominant alleles, the genotypes and phenotypes are known
3) Yes but also say that it is degenerate (amino acids have more than one code), the triplet codes are widespread and not universal, and some indicate a stop sequence.. (usually 3 marks)

I have no idea
Determine random numbers and randomly place the quadrat square during regular intervals in the habitat. Count the abundance (individuals of each species) in each square and calculate the percentage cover?

And I am sorry for my extremely late reply! And yes thats right. You could get some random coordinates you made up and have a tape laid on the floor actin like the x and y-axis and place your quadrat on your coordinates.

[sumsum123]

(Original post by Sparkzz)
1) Define homeobox genes and hox clusters
2) If glucose and lactose concentrations were equal in a medium containing E.coli, suggest how the bacterium decides to use lactose as a respiratory substrate instead of glucose?

seconds ones abit weird lol

1) Homeobox genes are genes that control the development of the body plan of an organism. And homeobox genes are arranged in hox clusters
2) I have no idea . Are you asking what happens when lactose is added to e.coli?

[christrev]

http://textbookofbacteriology.net/regulation.html

E. Coli would actually respire glucose before lactose, the reason here is because it would take two less enzymes (beta galactoside permease and beta galactosidase)