WJEC AS Biology BY2 - 3rd June 2013

Original post by anna1233

I put they are not resistant to dessication do you think I'll get it?

maybe a bod

Reply 102

For the growing shoots I said that the sucrose wouldn't be used for energy for growing therefor there would be more energy collected. Also that the plant would be smaller so that would mean that there would be less room for the sucrose to spread across

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Reply 103

Original post by mabli

The question stated that there was no ring, therefore there would be no effect

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i thought it asked about the concentration of the sucrose below the ring :confused:

Reply 104

laiyla

I hated the Sucrose/Phloem question!
And how were we possibly meant to get 10 marks for the artery and vein essay?

Reply 105

Increase since there wasn't any present when the ring was there

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Reply 106

It did but after the ring was removed

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Reply 107

Water_fall

So annoyed, hald the stuff I learnt didn't even come up! It was all plants :/ I hated the sucrose questions! What do you think the grade boundaries will be?

Reply 108

yoyox120

Well I think that went good EXCEPT the LAST question on RINGING. I misread it and talked about how the tissue underneath the ring was malgrown and eh crap...

About gills

They collapse = lower SA
They dry up = gas cant diffuse in

What did people put on the frikking question about the "ORIGINAL source of eergy moves the water up the plant". THAT WAS SO VAGUE I COULD'VE PUT GOD FOR THE LOVE OF GOD!!!!! LOL. I mean shiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii. Thas just stupidly vague. I put ATP though idk.

Reply 109

laiyla

Original post by yoyox120

Well I think that went good EXCEPT the LAST question on RINGING. I misread it and talked about how the tissue underneath the ring was malgrown and eh crap...

About gills

They collapse = lower SA
They dry up = gas cant diffuse in

What did people put on the frikking question about the "ORIGINAL source of eergy moves the water up the plant". THAT WAS SO VAGUE I COULD'VE PUT GOD FOR THE LOVE OF GOD!!!!! LOL. I mean shiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii. Thas just stupidly vague. I put ATP though idk.

I put ATP too, although I wrote photosynthesis first and then crossed it out.

Reply 110

Original post by laiyla

I hated the Sucrose/Phloem question!
And how were we possibly meant to get 10 marks for the artery and vein essay?

i waffled about both haivng collagen tunica externas resistent to overstretching, tunica medias thicker in the artery and endothelium which is one cell thick and smmoth to reduce friction. then i said that the tunica media in the artery has more elastic tissue to resist the high blood pressure of the oxygenated blood pumped away from the heart. it can also undergo vasoconstriction/dilation to regulate the blood flow. I also the elastic tissue helped for stretch and recoil to maintain the blood pressure. I also said arteries have a narrow lumen compared to veins which have a wide lumen. Veins have pocket valves to prevent backflow and less elastic tissue in the tunica media. Finally i talked about how skeletal muscles contract to help move the deoxygenated blood back to the heart. Thats all i remember...

(edited 10 years ago)

Reply 111

mo_sudani

I put sunlight as the energy source cause it said 'original'

Reply 112

Original post by mabli

It did but after the ring was removed

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******* How many marks was that?

Reply 113

mli26

I reckon this paper could have a boundary as low as Jan 2010 paper 46 for an A haha

Reply 114

yoyox120

Original post by laiyla

I hated the Sucrose/Phloem question!
And how were we possibly meant to get 10 marks for the artery and vein essay?

About this. I wrote two pages...LOL.

Arteries

High pressure due to left ventricle contraction
Hence need thick muscle wall + elastic tissue
Elastic Recoil
^ So pulse is detected/ flow is rhythmic.
Small lumen relative to diameter.
No valves
Collagen outer layer
Oxy blood to organs, so high pressure (Except pul artery)

Veins

Valves
Low pressure
Lil' muscle etc etc
No elastic recoil
No pulse
Large lumen
Venous return
Deoxy blood from organs, so low pressure (Except pul vein)

Here's a SIMILAR question that appeared before on this and the mark scheme.Might help cos it was virtually the same question just no capillaries

BY2 Jan 2004
Decribe the structure and function of veins, arteries, arterioles and capillaries. [10]
• (large vessels) have three layers in their walls*;
• (tough) collagen, elastic/muscular layer/endothelium/ correct reference to tunicae/description. Any 2. for 1 mark *;
• arteries deliver blood from heart/to other organs;
• they (elastic layer) resist/are under high pressure;
• smooth pressure pulses into continuous pressure;
• maintain blood pressure through elastic recoil (not: help pump blood);
• adjust their diameter to control blood flow;
• veins have thinner muscle layer than arteries;
• and relatively wider/large lumen;
• valves to ensure flow in one direction;
• veins deliver blood (from organs) to heart;
• endothelium is smooth (to reduce friction);
• capillaries have narrow lumen, restricting flow and slowing blood/reducing pressure;
• capillary wall just one cell thick (not: moist/thin)*;
• features increase the efficiency of exchange of materials/easier diffusion;
Maximum 10 marks from available 15
Points with * may be awarded for suitably labelled diagrams, annotations are required for those points making comparisons or relating structure to function. [10]

(edited 10 years ago)

Reply 115

2 or 3 I think, I wouldn't worry, I might be wrong

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Reply 116

Freyaa

[INDENT]

Original post by juniorx

******* How many marks was that?

3 Marks:/

Reply 117