OCR Biology F212 (Molecules, Biodiversity, Food and Health)- 21st May 2012

Original post by Maryb_101

Right people scrap your text books! If your going to revise then use the new spec mark schemes and the revise book! Oh my God i am so stressed out! :/ gaah this weekend is going to be mad, full day of bio-might even have to revise till late at night if im to get all this revision done :/ good luck to all you guys! I have tips on how to answer the b grade, c grade and A grade graph questions if anyone needs them!

can you give me them??

Reply 582

Original post by Sarabande

I suggest you open up your textbook and find the definition of species evenness. It has nothing to do with genetic diversity. It's to do with the relative amount of species in a habitat. Like if there were 3 rabbits and 53705 foxes. It isn't even is it?

Read this , this is from past paper why species eveness is important i am 100% confident i am correct (measures), abundance / numbers, of individuals in each
species ;
species evenness is more quantitative than
species richness ; ora
high(er) species evenness indicates
high(er) biodiversity ; ora
low species evenness indicates, dominance by / high
abundance of, one / few, species ; ora
used to calculate (Simpson’s) Index of Diversity ;
example used to illustrate explanation of mp 3 or 4 ;

Reply 583

Original post by otrivine

Read this , this is from past paper why species eveness is important i am 100% confident i am correct (measures), abundance / numbers, of individuals in each
species ;
species evenness is more quantitative than
species richness ; ora
high(er) species evenness indicates
high(er) biodiversity ; ora
low species evenness indicates, dominance by / high
abundance of, one / few, species ; ora
used to calculate (Simpson’s) Index of Diversity ;
example used to illustrate explanation of mp 3 or 4 ;

Lol no mention of genetic diversity there. I was correct. You just pointed your own self out.

Reply 584

Original post by Future_Dr

What does water has to do with the blood pressure? In the text book, it states something about salt in the blood drawing water in the artery and increasing the blood pressure. But then it also says that people with chronic hypertension are goiven 'water pills' which allow the kidneys excrete large amount of fluid. So what does water really do? If you have the Biology 1, OCR textbook please refer to page 150 last paragraph.

basically. having a fatty diet includes salts etc. increasing the salt content in ur body by the food u eat causes the water potential to be low because salt enters the blood.. therefore water moves in by osmosis down a water potential gradient into the blood causing a high blood pressure.. this raises the hypertension and can damage the arteries... then fatty substances deposit under the endothelium forming a athorema

and guys why is eveyrone so stressed out about LDLs and HDLs ... they wont come up if they came up in january...

Reply 585

Original post by Sarabande

Lol no mention of genetic diversity there. I was correct. You just pointed your own self out.

but i did say the biodiversity thing though :wink:

any ways
Ok
Why has vaccination been changed every year?

Reply 586

Original post by otrivine

but i did say the biodiversity thing though :wink:

any ways
Ok
Why has vaccination been changed every year?

The vaccination of what? Influenza?

Viruses/bacteria (I have no idea what the disease is) mutate and become resistant to drugs/antibiotics.
These viruses/bacteria survive with this gene and reproduce.
Their offspring have this gene.
Over generations the allele frequency for drug/antibiotic resistance increases.
Therefore new drugs have to synthesized to deal with drug/antibiotic resistant viruses/bacteria.

(edited 11 years ago)

Reply 587

Original post by Sarabande

The vaccination of what? Influenza?

Viruses/bacteria (I have no idea what the disease is) mutate and become resistant to drugs/antibiotics.
These viruses/bacteria survive with this gene and reproduce
Their offspring have this gene
Over generations the allele frequency for drug/antibiotic resistance increases.

of influenza sorry
ok you would lose the one mark you had to mention the key word Strain but the rest is perfect :wink:

Reply 588

Original post by otrivine

of influenza sorry
ok you would lose the one mark you had to mention the key word Strain but the rest is perfect :wink:

As in there are different strains of influenza?

What is a balanced diet? (2)

Why would it hard to test milk for lipids? (1)

What is a prosthetic group? (1)

How does a cofactor increase rate or reaction? (3)

Reply 589

Original post by Sarabande

As in there are different strains of influenza?

What is a balanced diet? (2)

Why would it hard to test milk for lipids? (1)

What is a prosthetic group? (1)

How does a cofactor increase rate or reaction? (3)

yes exactly cause they asked that in the june 2011 they wanted strain of new viruses which are mutants to get the 1 mark
1) A balanced diet is all the nutrients required for growth in appropriate proportions.
2) Because it forms a cloudy white emulsion and is difficult to check if it is milk.
3) , 4) did not revise that yet doing it later

Reply 590

theres a lot of people struggling with simple facts of smoking... and smoking i think will defintley come up.
these are all my notes on smoking using past papers and whoever finds this topic hard i suggest you have a look and learn it

TarGaseous exchange system
~ Damages cilia
~ Increases mucous production
~ settles in linings of airways and alveoli
~ inceases diffusion distance in alveoli
~ contains carcinogens
~ can cause formation of scar tissue
~ causes smooth muscle to contract to constrict the airway and blood flow to the alveloi

NicotineCardivascular system
~Constricts artieoles
~ increases: blood pressure
~ heart rate
~ breath rate
~ causes platalets to be sticky
~ alert/addictive

CO/Carbon Monoxidecardiovascular system
~ Damages lining of arteries
~ binds to hemoglobin reducing the amount of oxygen being carried for respiration

MARKSCHEME FOR EACH DIEASE.

CHRONIC/EMPHYSEMA
~ tar damages cilia
~ tar increases mucous production
~ tar not removed due to cilia being destroyed
~ phagocytes secrete enzymes
~ elasticsy of alveoli damaged
~ alveoli fail to recoil
~ coughing forces expiration as alveoli cannot stretch or recoil when breathing in and out
~ alveoli burst/ Surface area lost

LUNG CANCER
~ tar contains carcinogens
~ tar enters lungs
~ idea that cilia damages therefore more contact with tar and epithail cellls in lungs
~ carcinogens enter nucleus
~ causes mutation
~ uncontrollable cell division
~ formation of tumour

ATHEROSCLEROSIS
~ CO damages lining of artieries
~ saturated fats collect at site of damage
~ fatty substances deposit under endothelium
~ formation of atheroma

CHD

~ nicotine consticts artieroles, increases blood pressure and causes platalets to be sticky
~ this forms a blood clot in the lumen of the artery
~ co damages lining of arteries
~ fatty substances deposit under endothelium
~ formation of a atheroma
~ reduces lumen size
~ reduces blood flow to heart

USING THE MS ON CHD WE CAN CHANGE IT FOR A QUESTION ON STROKE IF IT COMES UP.. FOR THE CARDIVASCULAR DISEASES ITS ALL THE SAME AS THEY ARE ALL FORMED BY AN ATHEROMA

ALSO NOTE THAT IN THE MS'S THERES MARKS FOR NAMING WHAT THE CHEMICAL DOES.

SYMTOMS

Chronic/Emphysema

~Coughing
~ barrell chest
~ heart failure
~ shortness of breath
~ weezing

CHD/Atherosclerosis
~ Angina
~ heart attack
~ heart failure
~ shortness of breath
~ high blood pressure

Stroke
~ Sudden severe headache
~ sudden not being able to talk
~ sudden not being able to walk

Reply 591

Original post by Sarabande

As in there are different strains of influenza?

What is a balanced diet? (2)

Why would it hard to test milk for lipids? (1)

What is a prosthetic group? (1)

How does a cofactor increase rate or reaction? (3)

would the last one be that it binds to the enzyme/substrate therefore it allows the enzyme substrate complex to form more easily?

Reply 592

2/3. You forgot to mention that it slightly alters the active site to allow for more effective binding of the substrate to the active site.

Reply 593

Original post by Sarabande

2/3. You forgot to mention that it slightly alters the active site to allow for more effective binding of the substrate to the active site.

what about me?

Reply 594

Original post by otrivine

what about me?

Sorry, I forgot. You got full marks on the ones you did.

Reply 595

Original post by Sarabande

Sorry, I forgot. You got full marks on the ones you did.

ok why does increasing substrate concentration increases but then level off ?(3)

Reply 596

striver17

Original post by otrivine

i have a feeling there could be a long 6 marks question on biodiversity and there could be a 6 marks question on the experiment of reducing sugars

really? they already had a very unit 3 heavy paper in january....
i would have thought immune system?

Reply 597

Original post by otrivine

ok why does increasing substrate concentration increases but then level off ?(3)

Increasing substrate concentration increases rate but at a point number of active sites becomes a limiting factor. This is due to all active sites being occupied and not enough enzymes can cope with the increased number of substrates. Maximum turnover rate is achieved at this point.

Reply 598

arvin_infinity

3

Original post by Sarabande

As in there are different strains of influenza?

What is a prosthetic group? (1)

How does a cofactor increase rate or reaction? (3)

Prosthetic group is a cofactor and its presence is required for the activity of enzymes.. the small permanent non-protein group on the ezyme molecule (its not on the active site -as far as I know)

it contributes to the 3D shape and the charge of the enzyme molecules.

2)did you want to says how does coenyzmes increase ...?

Reply 599