Competition - post a photo you've taken of nature >>

OCR Biology New A-level H420 Paper 1,2,3 (2019) Predictions + Exam Discussion Thread

Scroll to see replies

Reply 980

BadLifeChoices12

If it helps, I remember the vales by trightcuspid? Like tricuspid is in the right side?

Original post by lionike123

The Valves between Atrium and Ventricles. Tricuspid Valve is the one in the right.

Reply 981

ra1500

Original post by lucia1234

what are the bicuspid and tricuspid valves???

they are the atrioventricular valves, on each side of the heart left and right to prevent backflow of blood going into the the ventricles from atria

Reply 982

ra1500

its either 0 (pure water) or negative, which has solutes in the water.

Original post by lionike123

For water potential can someone explain the signs negative and positive.

Reply 983

lucia1234

thank you

Original post by lionike123

The Valves between Atrium and Ventricles. Tricuspid Valve is the one in the right.

Original post by ra1500

they are the atrioventricular valves, on each side of the heart left and right to prevent backflow of blood going into the the ventricles from atria

Reply 984

sherzsy

carboaminohaemoglobin is when CO2 binds to Haemoglobin, as O2 unloads from Hb in presence of CO2. Carbonic acid is when CO2 and H20 react to form carbonic acid catalysed by the enzyme carbonic anhydrase.

Original post by lionike123

What is the difference between carbaminohaemoglobin and carbonic acid?

Reply 985

iniinininin

carbonic acid is the product from carbon dioxide + water and carbaminohaemoglobin is Hb + CO2 and accounts for 10% of what happens to CO2, 85% is transported as hydrogen carbonate ions and 5% just dissolves directly into the plasma, hope this helps.

Original post by lionike123

What is the difference between carbaminohaemoglobin and carbonic acid?

Reply 986

tchatel15

D wahey

Original post by lollypenguin

what does everyone need to get for uni in bio?

Reply 987

Tillyross5

What practicals have you guys learnt? Also what maths have you learnt?

Reply 988

Lol45678

I’ve not been writing my middle name in the forename spaces on the front pages of my exam.... is this a problem?????

Reply 989

tchatel15

No not really

Original post by Lol45678

I’ve not been writing my middle name in the forename spaces on the front pages of my exam.... is this a problem?????

Reply 990

lollypenguin

Original post by tchatel15

D wahey

damn wish I was in the same boat

Reply 991

tchatel15

I'm aiming for a B tho dw haha

Original post by lollypenguin

damn wish I was in the same boat

Reply 992

lollypenguin

https://linkto.run/p/4X2X5OQC

feel free to vote how you're feeling lmao and make the rest of us feel better knowing we're gonna fail collectively as a year :smile:

or if its just me lool

(edited 4 years ago)

Reply 993

lollypenguin

Original post by tchatel15

I'm aiming for a B tho dw haha

ah that's good! good luck man

Reply 994

idk01

It's the movement of assimilates to where they are needed and it works (supposedly) by the mass flow hypothesis:

1. At the source (e.g. leaves) sucrose is actively loaded into the phloem from surrounding tissue which lowers water potential causing water to enter phloem as well; the combination of the two create high pressure
2. At the sink (any part of the leaf using the sucrose), sucrose usually diffuses out of the phloem to where its needed, lowering the water potential so water also leaves by osmosis
3. Steps 1 and 2 create a large pressure gradient which is how it gets from source to sink

Original post by Tillyross5

Please can someone summarise translocation? The textbook makes it so long!