AS ORC Biology F212 june 2014

I thought overall it wasn't too challenging compared the any previous exams...

What did you put for other evidence of evolution?

I talked about DNA differing in species so species with similar DNA base sequence have a common ancestor and if their DNA is totally different then they've never been related. I also talked about the age of rocks, observable similarities and difference between species, characteristics, genes, taxonomy and phylogeny.
I am not sure if I could get all 7 marks with this answer though .

What did you put for the effects of components of smoking on cardiovascular system?

I was not sure what points they wanted precisely for the available marks, so I just filled the page with everything I knew about smoking and causing disease, such as:

1) Bacteria filled mucous would irritate the airways
2) Nicotine makes platelets sticky increasing chance of blood clot
3) Carcinogens forming tumours
4) Scar tissue in the lungs, and digestive enzymes destroying elastin
5) Tar would increase the diffusion distance for gaseous exchange

Obviously I filled the page with each point in more detail, but I thought the question was a bit vague...

That's pretty much what I do with all types of questions I write everything I know about the subject when I'm not sure, in hope of getting a few marks rather than leaving the page blank and having no marks.

I talked about nicotine and carbon monoxide and their effects on the heart rate and diseases they cause.

I was not sure what points they wanted precisely for the available marks, so I just filled the page with everything I knew about smoking and causing disease, such as:

1) Bacteria filled mucous would irritate the airways
2) Nicotine makes platelets sticky increasing chance of blood clot
3) Carcinogens forming tumours
4) Scar tissue in the lungs, and digestive enzymes destroying elastin
5) Tar would increase the diffusion distance for gaseous exchange

Yeah, seems like a reasonable way to go about it, overall I found the exams very easy, except for the question about other evidence for evolution and the smoking question.

What about you ?

I wouldn't say it was 'very easy' but I found the overall paper doable enough to get me an A or minimum a high B.

What grades are you aiming for in biology?

What did you write for the question about lily and conserving them in exsitu, seed bank advantage and the produCing modern cows from the wild one ???

EX SITU

Remove competition. Reduce selective pressures. Reduce chance of disease as they're in a sterile environment. Prevent they being dug up to be sold and also to prevent predation. To allow their optimum conditions to be met to increase survival rate. And I cant remember what else...

Seed bank there are loads... Takes up less space, Freeze them to reduce chance of disease preserving their genome, costs less - don't need to feed or water them. Collecting seeds will not damage the enviroment.

Modern cows was just standard artificial selection...

What did you write for the question about lily in exsitu conservation 4 marker and structure of DNA for DNA replication...

I wrote about the structure of DNA and the process of its replication but didn't really links the two together, I don't no if il get even a mark for that

Oh okay...thanks...I think wrote wrong stuff about the modern cows....what did you write for the question about overconsumption of milk and beef causes malnutrition and the question where you had to draw conclusions about lung cancer and death rate ...oh and the properties of cellulose??

For the lily question, I wrote about
-seeds being stored and allowed to germinate in protected surroundings
-Lots of seeds can be stored without taking too much space
-Easy for scientific research when ex-situ
-Safe environment

And for DNA, I talked about:

-Double helix unzipping by enzyme helicase
-Hydrogen bonds breaking
-Bases exposed
-Free nucleotide complementary base purine-pyrimidines
-Hydrogen bonds formed
-DNA polymerase

I wrote pretty much everything I knew about the topic

Over consumption of milk I was unsure... but I just spoke about how Milk and Beef are both high in fats, thus is fat consumption is greater than fat respired/metabolised then it will be stored as adipose cells in the body leading to obesity. And also that beef is high in Saturated fat, which can form LDL's with Chol. And protein, leading to athersclerosis which is related to Stroke and CHD.

Lung cancer and death rate I was also unsure about, I just said smoking is a cause of both. And that Smoking causes Lung cancer so must contain a carcinogen.

Properties of cellulose I put: Insoluble - Doesn't affect water potential.
Strong - Keeps rigidity of cell. And also that is was permeable to water.

None of these are certain, or even correct, answers by the way - it's just what I put...