Ocr f215: 27/1/11

Yea same boat.I got a D too but anyways this time My plan is to ace it.Last time I completely skimmed through genetics and left awful lot on animal behavior LOL.
Not happening now.So when are you planning to revise? I have 3 more exams before this one.I have completely finished variation/genetics.I am good with biotech,that shouldn't be a worry.

At the moment I've memorised my notes so just saying them over and over again to myself at the moment so nothing serious as I have one exam before it and that's this Friday, so once that's done, I'll have 12 days of crazy F215 revision

Good good.Perhaps we could help each other out.

Definetly I'll be on here for whole of next week and the week of the exam, so we can share some knowledge!

http://www.execulink.com/~ekimmel/drag_gr11/sexlink.htm

Whats the answer for the last two questions about offspring?

Nevermind :P just realised why it was coming up wrong silly percentage sign

Ouch not much time left damn.So far I have just completed variation/and stuff related to genetics. Gr...

Alrighty lemme recall... hmm
Biological def. of species: A group of individual organisms that share same morphology,physiology,anatomy and are able to breed with each other to produce fertile offspring.

In biological species concept two criteria are needed:
1) It applies to sexually produced organisms.
2)Species extinct,produced asexually/fossils don't get categorized.
Hence the disadvantage over this concept is that it limits the no. of species(less diversity)/ignores organisms produced asexually.

Evolutionary (phylogenetic) concept deals with how close do two organisms are to each other i.e how back do they share common ancestry.If there are signs of having common linkage then these are classified as other species without even knowing whether there is a reproductive isolation btw. the two species or not.

for example: A duck living in region X and other one living in region Y,have different colour ,nothing is known about their isolation = classified separately.

The advantage of this method is that it widens the no. of species and includes what the above concept excluded.The only dis-advantage is that it's not reliable since any person/organisation could come up wit their own no. of species based on their said assumptions.

The book which I have by Mary jones includes only A.I of cow (

Artificial Insemination:
A.I is done to increase the rate of offspring's compared to the wild population.
A chosen bull's semen is collected.In the wild this would only impregnate a cow but in A.I a large no. of cows are impregnated with the semen.

The bull goes through progeny testing.To check whether it has the suitable traits or not.If it's female offspring's show the desired traits,farmers use it's sample for the breeding programme.All this takes time hence why semen is stored/frozen for a longer period (2 years approx).In during which the calf matures and so forth.

Embryo transplantation:
A chosen cow with the desired trait is a. inseminated with semen.She's fed with different hormones for her to super ovulate.At the oviducts embryo (fertilizes).In the uterus it's washed out of the cow/ Now it could either be further divided into two embryo + or transfered into surrogate mother/s.
The surrogate mother needs to be fed with same hormones for her uterus to carry.
Surrogate mother is of low value compared to the parent cow.

Quick meiosis question...making me confused.

Homologous pair-does this refer to the 2 chromatids conected by the one centromere ie: 'X' or does it refer to 2 of the same chromosome ie: 'XX', if so than it can also be as 'II' (chromosome not replicated yet...)

bivalents: refers to a pair of chromosome temporarily united. Does this mean 'X' or 'XX'?

Are bivalents the same as a homologous pair or not?

Four Chromatids or tetrads.
Before meiosis dna replication occurs in which ,say for example l becomes ll.
Since humans have two sets of each chromosome you end up with the homologous pair consisting of ll-ll.
Bivalents is when ll or in your example XX join during prophase one.Yep bivalents are same as homologous pairs.

Hey remember me?

I got 90/150 which was terrible, so I am resitting this module only, although I dont see the point as I cant go up. I would need like 131/150 to go up a grade and I haven't started proper revision yet!

But I do have an unconditional offer so far plus Im looking at school leaver schemes which need a maximum of 300 UCAS points anyways, which I have.

How are you feeling for this exam?

Well I got a D on it last time.I am sitting this module only and so I am aiming to achieve 100% on this.So far I have gone through genetics,variation.Tonight I will finish vegetative propagation,and biotech stuff. =]
Twelve days left =P
That's great =]

Ah. I somehow cant keep concentrating. I had planned on doing 6-9 pages today but only completed one

I remember someone put some notes up which are answers to each syallabus point which Im hoping will get me through the pages quicker. Are you retaking any other subjects?

I'm also resitting this exam, got a C in it, but A's in all my other Bio modules, so need to try and get an A in this exam! My main problem is lack of practice questions, I can't seem to find any papers, apart from the specimen one and the one that I sat in June. Does anyone have access to questions, particullarly ones regarding genetics and the whole genetic diagrams/epistasis/chi-squared test crap etc? Would help a million! The first topic is the hardest and the rest are ok, just have to crack genetics and fingers-crossed i'll be fine

X

Question anyone?
If chi squared value is larger than the critical value, how can this be explained genetically?
also, can anyone explain genetic drift/founder effect?

I remember someone put some notes up which are answers to each syallabus point which Im hoping will get me through the pages quicker.