AQA BIOL5 ~ 17th June 2013 ~ A2 Biology

oh i think that bit is ok

how confident are you on the dna bit towards the end and the essay in general

how can i better myself if i have no lessons to go to ??

Temper hahaha.

So when are we gonna start question testing? Funny how we've done it on every thread so far

I'll start it off then, will do non-human bits since I suck at those parts.

How does a kinesis keep a maggot in favourable conditions?

TEMPOral. Tempo = Speed.

Do you have any way of remembering which is temporal and which is spatial? I can't think of anything handy haha

Oh lordy, moves more rapidly/makes less frequent turns when in unfavourable conditions in order to make it more likely to leave the area. When in favourable conditions, it moves less rapidly/turns more frequently so its more likely to stay in those favourable conditions.

Define negative feedback

Everything is right, except it turns more frequently in unfavourable conditions, and turns less frequently in favourable conditions (got the two the wrong way around).

Negative feedback is when a change in the system causes a series of changes that brings the system back to the norm/set-point, reducing the deviation of the system from the set point.

Does anybody have the jan 2013 paper and mark scheme...Pleaseeee??

It's non-existent.

If we're going to do this question thing again, ask a question when you answer one, otherwise it just dies extra quickly as seen above

1) State 2 differences between the endocrine system and the nervous system
2) Explain what the response is when there is a decrease in blood glucose levels.

If we're going to do this question thing again, ask a question when you answer one, otherwise it just dies extra quickly as seen above

1) State 2 differences between the endocrine system and the nervous system
2) Explain what the response is when there is a decrease in blood glucose levels.

2) Receptors on the alpha-cells in the pancreas detect fall in blood glucose concentration, so secrete more glucagon into the blood. Glucagon binds to specific/complementary receptors on liver cells. Glucagon acts as the primary messenger, the glucagon-receptor complex that forms activates an enzyme that hydrolyses ATP into cAMP. cAMP acts as the secondary messenger, and activates another enzyme that breaks down glycogen stored in liver cells into glucose. Glucose moves from the liver cells from the blood (?diffusion/active transport). Glucagon also stimulated the liver cells to increase the rate of gluconeogenesis from amino acids and fatty acids/glycerol.

What is the role of oestrogen in gene expression?

Why did I get so much neg from this post?

Seems like we've got some overzealous negger's on the thread