[hash007]

(Original post by rf229)
Does anyone know of any websites with practice questions? (not the ocr past papers)

http://www.freeexampapers.com/past_p...Biology%2FOCR/

ignore, forgot to read (not the ocr past papers)

[kishenp]

Can someone help in where they got the answers on the mark scheme
It is question 2b(ii) on June 2010 paper
Thank you

[Fatima0065]

What si conservation adn why is it bbeter than perservation..What are the advantages and dsiadvanatges to conservatinon

[otrivine]

(Original post by Fatima0065)
thanks!! :d

hi sure ok lets start

State 3 differences between PCR and DNA replication (3)

[Fatima0065]

(Original post by otrivine)
hi sure ok lets start

State 3 differences between PCR and DNA replication (3)

PCR requires dna polymerase, a primer etc
only forms one new strand

Dna replicatio:semi-conservative..2 new starnds are formed..RNA polymerase is used..i think ...hm not sure

[Fatima0065]

describe on example of primamry succession resultin in a climax community

[otrivine]

(Original post by Fatima0065)
What si conservation adn why is it bbeter than perservation..What are the advantages and dsiadvanatges to conservatinon

conservation = is to maintain biodiversity and help to look after species in a (habitat/area) and it is better than preservation as they are looked after in their own environment
advatages- no hunting , no toursts throwing litters on the floor, maintains biodiversity, can be used for education to teach people, animals are taken care and looked after so reduces susceptiability to diseases and are well supplied with food.

disadvantages= expensive, inbreeding , competition for food are resources with other species

[Fatima0065]

(Original post by otrivine)
conservation = is to maintain biodiversity and help to look after species in a (habitat/area) and it is better than preservation as they are looked after in their own environment
advatages- no hunting , no toursts throwing litters on the floor, maintains biodiversity, can be used for education to teach people, animals are taken care and looked after so reduces susceptiability to diseases and are well supplied with food.

Disadvantages= expensive, inbreeding , competition for food are resources with other species

correct

[otrivine]

(Original post by Fatima0065)
PCR requires dna polymerase, a primer etc
only forms one new strand

Dna replicatio:semi-conservative..2 new starnds are formed..RNA polymerase is used..i think ...hm not sure

yep good 3/3

[Fatima0065]

(Original post by otrivine)
yep good 3/3

IS IT REALLY? I THOUGHT I WOULD GET IT WRONG..HAVENT COME ACROSS DIFERENCES... and is rna polymerase used in dna replication? :/

[otrivine]

(Original post by Fatima0065)
describe on example of primamry succession resultin in a climax community

an example is where the plants grow near the beach but in the sand dunes and they can resist water spray, nutrients and so they keep spreading to larger sand done and provides stability.
one question for this do we need to learn all the plant names???

[Fatima0065]

(Original post by otrivine)
an example is where the plants grow near the beach but in the sand dunes and they can resist water spray, nutrients and so they keep spreading to larger sand done and provides stability.
one question for this do we need to learn all the plant names???

Nope..you have to say this
-uncolonised area
pioneer community grows
larger plants succed smaller ones
until a climax community is reached

[otrivine]

(Original post by Fatima0065)
IS IT REALLY? I THOUGHT I WOULD GET IT WRONG..HAVENT COME ACROSS DIFERENCES... and is rna polymerase used in dna replication? :/

no rna polymerase is not used for dna replication , dna replication uses enzyme DNA POLymerase remember dont make that mistake

yes you do get 3 marks cause the marks are
1) primers are added so reaction can proceed
2) heating and cooling for strands to separate and anneal
3) replicates only dna sequence not entire chromosome

but you got the marks for the DNA

[Fatima0065]

(Original post by otrivine)
no rna polymerase is not used for dna replication , dna replication uses enzyme DNA POLymerase remember dont make that mistake

yes you do get 3 marks cause the marks are
1) primers are added so reaction can proceed
2) heating and cooling for strands to separate and anneal
3) replicates only dna sequence not entire chromosome

but you got the marks for the DNA

okai thanks..as me another one

[otrivine]

(Original post by Fatima0065)
okai thanks..as me another one

ok
What is the advantage for conjugation (2)

[Fatima0065]

(Original post by otrivine)
ok
What is the advantage for conjugation (2)

Congujagation allows bacteria to exhange DNA whic causes them to spread advantageous alle quicker, and hence become resistant tocertian antibiotics etc
describe the role of the brain and nervous system in the co-ordination of muscular movement;

[otrivine]

(Original post by Fatima0065)
Congujagation allows bacteria to exhange DNA whic causes them to spread advantageous alle quicker, and hence become resistant tocertian antibiotics etc
describe the role of the brain and nervous system in the co-ordination of muscular movement;

yes but you forgot the key word plasmid its the plasmid which causes the antibiotic resisatance

[Fatima0065]

(Original post by otrivine)
yes but you forgot the key word plasmid its the plasmid which causes the antibiotic resisatance

ahh yes silly me..i hope i dont do this is the exam

[otrivine]

(Original post by Fatima0065)
Congujagation allows bacteria to exhange DNA whic causes them to spread advantageous alle quicker, and hence become resistant tocertian antibiotics etc
describe the role of the brain and nervous system in the co-ordination of muscular movement;

role of brain that control the movement and posture is the cerebellum and the role of the cerebellum is to control the posture and movement. The nervous system consitsts of the spinal cord and brain with the neurones such as motor/relay and sensory neurones. so the sensory receptors detects change in movement and sends the nerves from the neurones all the way to the brain to the cerebellum so that the brain has the information and helps the movement of the joint/bones. also there is the peripheral system where the autonomic system has sympahteic and parasymphateic and so parasymphateic is when you are relaxed it releases noradrenaline when it attaches with the ganglion and symohateic acteylcholine. this helps to cause movement of bone and the acetylcholine is then used for the movement of joint which the ca2+ released from the sacroplasmic reticulum depolarization e.t.c

[Fatima0065]

(Original post by otrivine)
role of brain that control the movement and posture is the cerebellum and the role of the cerebellum is to control the posture and movement. The nervous system consitsts of the spinal cord and brain with the neurones such as motor/relay and sensory neurones. so the sensory receptors detects change in movement and sends the nerves from the neurones all the way to the brain to the cerebellum so that the brain has the information and helps the movement of the joint/bones. also there is the peripheral system where the autonomic system has sympahteic and parasymphateic and so parasymphateic is when you are relaxed it releases noradrenaline when it attaches with the ganglion and symohateic acteylcholine. this helps to cause movement of bone and the acetylcholine is then used for the movement of joint which the ca2+ released from the sacroplasmic reticulum depolarization e.t.c

WOW!..thats really good