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AQA BIOL2~3rd June 2013~AS Biology (Now Closed)

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If there was a question about how water moves through the roots to the leafs would we have to mention the apoplastic and symplastic pathway?

Reply 2281

oak12

topics that may appear (based on them not really featuring), i theorise:

- meiosis aspects
- exchange in insects
- exchange in fish
- absorption in roots of plants
- xerophytes
- conjugation

(atleast 2!)

Reply 2282

oak12

Original post by laithmo96

If there was a question about how water moves through the roots to the leafs would we have to mention the apoplastic and symplastic pathway?

depends on number of marks, more then 3, then probably so

Reply 2283

blondie24

Original post by PKMN TRN JAM

1 question,
Is there fluid in any part of an insect's tracheoles?
Teachers have told me different to my textbook unless I either wasn't listening or somehow can't read.

Quote me please :biggrin:

REP AVAILABLE

I think there is but right at the end of the tracheoles but i don't think we need to specifically know about the fluid. I think the respiratory gases diffuse from the tracheoles in to the fluid and then into respiring cells

Reply 2284

elliewoodheadx

Is this right?
Vena cava: deoxy blood from the lower body to the heart
Aorta: oxy blood from the heart to the whole body
Pulmonary artery: deoxy blood from the heart to lungs
Pulmonary vein: oxy blood from the lungs to the heart
Hepatic artery: oxy blood from the heart to gut/liver
Hepatic portal vein: partially oxy blood from gut to liver
Hepatic vein: deoxy blood from liver to heart
Renal artery: oxy blood from the heart to the kidneys
Renal vein: deoxy blood from kidneys to the heart

:confused:

Reply 2285

laithmo96

Original post by oak12

Can you please summaries ''absorption in roots of plants'' :biggrin:

thanks

Reply 2286

oak12

Original post by dooobie_

I think antibiotics and cell cycle will definitely come up. If there are big markers about plants I'm screwed because I find it so hard!

Posted from TSR Mobile

any questions on it?

Reply 2287

SophieL1996

has there ever been any q's about fish or insects?

Reply 2288

oak12

Original post by laithmo96

Can you please summaries ''absorption in roots of plants'' :biggrin:

thanks

ok:

- mineral ions are absorbed by active transport, from the soil to the xylem via the roots
- this lower water potential in the xylem
- so water follows in by osmosis

- water takes a path thru the root hair cells, then cortex cells, then endodermis cells into the xylem

- it may move in by the symplast pathway, this is directly thru the cells via the cytoplasm
- the cells are connected to each other by the plasmodesmata

- the water may also move in by apoplast pathway, this is between cells and in the cell wall
- this occurs between the cells until the endodermis cells
- they have a casparin strip, an impermeable waterproof barrier
- water moves into the endodermis cell and then into the xylem

Reply 2289

oak12

Original post by SophieL1996

has there ever been any q's about fish or insects?

i remember ones on fish

Reply 2290

Manni

Original post by SophieL1996

has there ever been any q's about fish or insects?

Fish yes, insects no

Reply 2291

SophieL1996

Original post by Manni

Fish yes, insects no

which past paper do you know? as I cant find it

Reply 2292

username853993

Original post by oak12

That would be ****ing perfect if they all came up I think i'd have to kiss my paper lol

Reply 2293

Meathead-jack

Do they always give you the species diversity index formula in this exam???

Reply 2294

Hi, How are you ?

Original post by PKMN TRN JAM

1 question,
Is there fluid in any part of an insect's tracheoles?
Teachers have told me different to my textbook unless I either wasn't listening or somehow can't read.

Quote me please :biggrin:

REP AVAILABLE

I think so, in some question I v'e done they talked about the fluid moving into the tissue to reduce the diffusion pathway, I think. So technically yes I suppose. Our teachers haven't talked about it either.

Reply 2295

Manni

Original post by SophieL1996

which past paper do you know? as I cant find it

fish one is june 09 q8

Reply 2296

lorobolorolo

Original post by ibmb24

Not sure exactly why, but in the process of CO2 getting in the leafs they diffuse into the air spaces and move down the diffusion gradient to the mesophyll cells that use it up for photosnthesis

Thanks

Reply 2297

Suzanna5678

Original post by oak12

its for mammal size and affinity, should read:

- smaller the mammal
- larger the surface area to volume ratio
- more heat loss
- respires more to generate heat
- curve is to the RIGHT
- lower affinity
- so more oxygen is unloaded to respiring cells

Is it the opposite for a large mammal ?