AQA BIOL5 Biology Unit 5 Exam - 22nd June 2011

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Complementary RNA strand only since it's only asking for the pre-mRNA bases.

thanks mate :smile:

But if it continues and asks for the DNA strand, then you would give the complementary bases and the original bases, providing you remove the introns so you only show the complementary bases of the exons and the tRNA anticodons, right?

Reply 2141

IFondledAGibbon

Original post by Tericon

Related question: How does IAA inhibt root growth? I mean in the CGP, it says it inhibts, and then it says it causes it to bend...but if its bending, isn't it growing?

Please help, getting a bit panicy now :smile:

I don't think it does inhibit root growth. It's an auxin; which is defined as 'A plant hormone that causes the elongation of cells in shoots and is involved in regulating plant growth.'

Reply 2142

Jin3011

Original post by i.love.heroes

how are you going to revise for the essay?

Look over a few things on DNA proteins and all that stuff and look over some of my own essays that I've done on paper.

Reply 2143

choc1234

spec says
balance the humanitartian aspects in recomb dna technology with the opposition from environmentalists and antiglobalisation activists.
HUH?

Reply 2144

arvin_infinity

Original post by IFondledAGibbon

I don't think it does inhibit route growth. It's an auxin; which is defined as 'A plant hormone that causes the elongation of cells in shoots and is involved in regulating plant growth.'

FSH is extracted from the urine of menopausal women. The menopause is when a woman’s menstrual cycle stops during middle age. By this time, menopausal women have few follicles left in their ovaries. These women have large amounts of FSH in their urine.
Explain why these women have large amounts of FSH in their urine.
22:24
(2 marks)

Thought its to do with progesterone ..

Someone help me out with this question

+rep

Reply 2145

M | k e

I've not even bothered revising for the essay, just learning the unit 5 topics then relying on my memory/luck on what the essay is about to get me through that with a decent mark. Plans to think of at least 1 topic from each unit on the essay then just go into detail for that, seen as its only 16 marks for actual knowledge, it's only actually 4 marks per unit if I think of it that way :smile:

.

Plus I'm doing biology all in one year so only did unit 1 and 4 in january, and unit 2 a few weeks back so guess I've had less time to forget it all compared to most people :tongue:

Reply 2146

User12399

think, im going to go to sleep now. reread the essays i did. did about 5, and read a couple of my class mates as well. had a quick look over revision guides from AS as well. BIOL4 is fresh in my mind because I resat it. Hope a cycles essay comes up.

Reply 2147

Jin3011

Original post by won-derer

thanks mate :smile:

lol sorry, I didn't quite get that.

Reply 2148

Phalange

Original post by choc1234

hmm i thought that IAA causes a decrease in growth in root cells so if you place a root hoizontally there will be a high concentration of IAA on the lower surface aand so cell elongation will cause the root to bend down towards gravity instead of up (which it would if IAA stimulated the growth of root cells as it does in shoot cells)
not sure myself tbh

Ya I meant what if the root is VERTICAL? If it is horizontal, then the IAA is in high conc at the "bottom" - inhibits growth in roots and causes the "top" to bend downwards.

Roots - IAA inhibits
Shoots - IAA elongates

If it was vertical, I think the IAA would go to the "bottom" and inhibit further growth. UNLESS it doesn't grow from the tip of the root. Nvm :smile:

don't confuse yourself before exam like me :biggrin:

Reply 2149

Phalange

Original post by gorillaz121

Gravity has little effect on IAA, the only thing you need to know is that the IAA is produced in the tip of the plant and is then spread to all sides of the plant. After this the light shining on one side causes the IAA to move to the shaded side of the plant and accumulate there. IAA causes elongation of plant cells so the shaded side of the plant grows faster and the plant bends towards the light so photosynthesis is at its max. There is very little if any mention of IAA affecting the growth in roots in this specification :smile:

The only chemoreceptors to worry about are the ones in the aorta and carotid arteries, they send the impulses to the medulla oblangata which sends impulses via the para- or sympathetic nervous system to the SAN. No point going overboard and revising outside of the course, we'll be given enough information in the actual tests if it goes outside the syllabus. :smile:

Ah ok thanks I'll just go over it with my teacher before exam for reassurance :biggrin:

Reply 2150

NRican

Can anyone quickly summarise osmosis in Cholera and Digestion (small intestine - dehydration etc)

:smile:

Would be greatly appreciated. Unit 1 stuff not coming back to me :frown:

Reply 2151

nbajaj1

I keep getting mixed up with the gluconeogenesis...gylcogenolysis and glycogenesis.
which one is which?
help :I

Reply 2152

SarahTM

All nighter anyone? :biggrin:

Reply 2153

Jin3011

Original post by arvin_infinity

Few follicles - low oestrogen production - oestrogen inhibits FSH - less oestrogen means less FSH inhibition and so more is realsed from pituatary glands.

Reply 2154

Master.K

Could somebody explain restriction mapping to me please. :smile:

Reply 2155

SirMuffin

Folks... Can anyone kindly give me the AQA definitions (if such a thing existed) for negative feedback and positive feedback?

Reply 2156

SarahTM

Original post by nbajaj1

I keep getting mixed up with the gluconeogenesis...gylcogenolysis and glycogenesis.
which one is which?
help :I

Glycogenesis is where glucose is converted into glycogen...

Gluconeogenesis is where glycogen is converted to glucose with the aid of the enzyme glucagon :smile:

Reply 2157

IFondledAGibbon

Original post by arvin_infinity

Random quote? :P

If they haven't got many follicles this probably means they're not secreting as much oestrogen. Therefore, nothing is inhibiting further release of FSH from the anterior pituitary. Since there isn't many follicles to be stimulated by the FSH it just is released in the urine as waste.

Reply 2158

cws121

Original post by nbajaj1

I keep getting mixed up with the gluconeogenesis...gylcogenolysis and glycogenesis.
which one is which?
help :I

gluconeogenesis is the formation of glucose from fatty acids and glycerol- i.e. forming new glucose (glucagon activates this by binding to liver)

glycogenesis- the formation of glycogen from glucose (insulin activates this)

glycogenolysis- the formation of glucose from glycogen (strictly speaking we dont have to know the name for that- we just have to know that glucagon activates an enzyme that breakdown glycogen to glucose)

hope that helps

Reply 2159

M | k e

Original post by nbajaj1

I keep getting mixed up with the gluconeogenesis...gylcogenolysis and glycogenesis.
which one is which?
help :I

Lysis = cut (break down)
Genesis = generate :tongue:

So gluconeogenesis, generating glucose from non-carbohydrate sources. (Glucagon)
Glycogenesis, generating glycogen from glucose (Insulin)
Glycogenolysis, cutting (breaking down) glycogen to form glucose. (Glucagon/Adrenaline)

So yeah just remember lysis is breaking down, genesis is forming, and anything with Glyco in involves glycogen :biggrin: