AQA AS Biology Unit 2 - 1 June 2015

Personally i would just do all the papers again, by doing papers you are not only learning exam techniques, but you are also revising aswell. You can know the spec and all the info like the back of your hand, but if you don't know how to answer the question in the way that AQA want, its useless.

Do all the past papers, there's 10.

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Do then again.Exam technique for AQA just as important as info.

hey guys is this correct sequence - partly due to solar energy transpiration occurs - water evaporates form the cell walls of leaf mesophyl cells, before the water vapour leaves the leaf via the stomata down a WP gradient. This reduces the WP in the leaf mesophyl cells creating a WP gradient down which water moves out of the xylem and into the mesophyl cells by osmosis. Due to the cohesion between water molecules (as a result of hydrogen bonding) , this creates a tension in the (water in the) xylem as water is pulled as a continuous collum up the xylem. Adhesion between water and the xylem wall helps to maintain this continuous column of water and stop it breaking under the tension .

Can someone pls give me two reasons why water uptake may not be the same as the rate of transpiration?

Species diversity is dependant on
-number of diff species
-population of each species

We want high species diversity because:
For a stable ecosystem. species are interdependent. Think food chains. Therefore low species diversity means extinction more likely and less food options if a species does become extinct,this therefore isn't a stable ecosystem

DEFORESTATION can lower species diversity
reduce variety of plant
Reduce variety of food sources
Reduce habitats
Lower animal species diversity

That's the bare minimum to know.
When considering something's effect on species diversity usually mention
-habitats
-food sources
-plant species variety
-Animal species diversity

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can anyone explain how to do 5)a)iii) on the june 2012 paper:

http://filestore.aqa.org.uk/subjects/aqa-biol2-qp-jun12.pdf

thanks

Can someone pls give me two reasons why water uptake may not be the same as the rate of transpiration?

Can someone pls give me two reasons why water uptake may not be the same as the rate of transpiration?

Can someone pls give me two reasons why water uptake may not be the same as the rate of transpiration?

Can someone pls give me two reasons why water uptake may not be the same as the rate of transpiration?

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What would be some economic and ethical arguments for maintaining biodiversity?

Ethical argument:
Prevent extinction
loss of populations
reduction in populations
loss of habitats
save organisms for future generations

Economic:
medical / pharmaceutical uses;
commercial products
tourism;
agriculture;
saving local forest communities;

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It looks right,bit I thought tension is created when by transpiration.

hey guys is this correct sequence - partly due to solar energy transpiration occurs - water evaporates form the cell walls of leaf mesophyl cells, before the water vapour leaves the leaf via the stomata down a WP gradient. This reduces the WP in the leaf mesophyl cells creating a WP gradient down which water moves out of the xylem and into the mesophyl cells by osmosis. Due to the cohesion between water molecules (as a result of hydrogen bonding) , this creates a tension in the (water in the) xylem as water is pulled as a continuous collum up the xylem. Adhesion between water and the xylem wall helps to maintain this continuous column of water and stop it breaking under the tension .