[SHAH :)]

yhh sure. that would help me revise
you can start

[Future_Dr]

I miss the F211. It wasn't a lot to learn. plus I enjoyed the body stuff, like lungs, gas exchange system and the heart. But this F212, is really too much to know. Still have biodiversity, conservation, evolution, food production to go.

[rainbow_kisses]

(Original post by Future_Dr)
I miss the F211. It wasn't a lot to learn. plus I enjoyed the body stuff, like lungs, gas exchange system and the heart. But this F212, is really too much to know. Still have biodiversity, conservation, evolution, food production to go.

Good luck, its a trial I know!

[skylight17]

(Original post by Axion)
tis :P the heart would do .

Anyone want to do a question exchange. whreby every post you write, has to end with a question and a set number of marks and the next person has to answer it?

Describe and explain the main features of the gas exchange system (lungs) and how it ensures effcient gas exchange? (6-8)

Why do large organisms need a specialised gas exchange system? (4)

Outline the mechanism for inspiration and expiration? (8)

Which of these structures have a squamous epithelium? - trachea, bronchus, bronchiole, alveolus (1)

How do you measure Oxygen uptake by using a spirometer? (4)

[Future_Dr]

Does anyone have the recent january 12 F211 Paper? Please!!!

[SHAH :)]

(Original post by Future_Dr)
Does anyone have the recent january 12 F211 Paper? Please!!!

here you go
http://www.thestudentroom.co.uk/show....php?t=1943168

[Axion]

• Get the person to breathe in and out at rest
• compelete this for about 1 minute
• obtain the trace and draw a line against all the peaks during the first minute recorded
• measure the total decrease from the first peak to the last peak
• this is representative of the oxygen uptake

(Original post by skylight17)
Describe and explain the main features of the gas exahcnage system and how it ensures effcient gas exchange? (6-8)

Why do large organisms need a specialised gas exchange system? (4)

Outline the mechanism for inspiration and expiration? (8)

Which of these structures have a squamous epithelium? - trachea, bronchus, bronchiole, alveolus (1)

How do you measure Oxygen uptake by using a spirometer? (4)

Is question 1 referring to the lungs? you said 'the' gas excahgen system

large organisms need one because

• they are mobile are have large requirements
• the need to be able to remove waste products quickly
• they have a small surface area to volume ratio
• therefore diffusion is not enough

alveolus have squamous epithelium

Inspiration

• diaphragm and ICM contract
• ribs up and out, diaphragm flattens
• volume thorax up
• pressure thorax down
• air flows in down pressure gradient

I'll let someone else do expiration :P

[Axion]

Describe the structure of ribosomes (1 mark)

[TaraBelle]

(Original post by Axion)
Describe the structure of ribosomes (1 mark)

do we need to know this?

[ohmyBEAUT]

(Original post by skylight17)
Describe and explain the main features of the gas exchange system (lungs) and how it ensures effcient gas exchange? (6-8)

Why do large organisms need a specialised gas exchange system? (4)

Outline the mechanism for inspiration and expiration? (8)

Which of these structures have a squamous epithelium? - trachea, bronchus, bronchiole, alveolus (1)

How do you measure Oxygen uptake by using a spirometer? (4)

I'll do the expiration one, if you two don't mind?

Diaphragm relaxes and is pushed up by the digestive organs.
The intercostal muscles relax and the ribs fall.
Volume of chest cavity decreases.
Pressure in lungs is below atmospheric pressure, hence the air moves into the lungs.

[Axion]

(Original post by TaraBelle)
do we need to know this?

Yep.

Ok I'll ask another one.

List 3 functions of cystoskeletons

[SHAH :)]

can someone please help me with calculating the actual length i never get it right.
in the jan 2009 paper Q1aiii, you are meant to go 20x15 divided by 80
but where does the 80 come from :s

helpppppp

[Axion]

And here is one question you you BEAUT.

list the resolution and magnifications of the light, TEM and SEM

[Axion]

(Original post by SHAH :))
can someone please help me with calculating the actual length i never get it right.
in the jan 2009 paper Q1aiii, you are meant to go 20x15 divided by 80
but where does the 80 come from :s

helpppppp

cell image length is 80mm, real cell length = 20micrometres

therefore 1mm = 0.25 micrometres

Therefore 0.25 micrometres x 15 (the length of the mitochondrion)

=3.75micrometres

[sumsum123]

(Original post by Axion)
Describe the structure of ribosomes (1 mark)

it has a large subunit and a small subunit.Why is imporant that during mitosis, the length of time the the chromosomes are supercoiled is as short as possible? Explain what happens during G1, G2 and the S-phase during interphase.

[ohmyBEAUT]

(Original post by Axion)
And here is one question you you BEAUT.

list the resolution and magnifications of the light, TEM and SEM

Light - 200nm / 1500x
TEM - 0.1nm / 500 000x
SEM - 0.1nm / 100 000x

I'll give you a question in a second.

[Axion]

(Original post by sumsum123)
it has a large subunit and a small subunit.Why is imporant that during mitosis, the length of time the the chromosomes are supercoiled is as short as possible? Explain what happens during G1, G2 and the S-phase during interphase.

but what is in composed of?

cell growth, organelle replication, checking and copying of genetic material

[Axion]

(Original post by ohmyBEAUT)
Light - 200nm / 1500x
TEM - 0.1nm / 500 000x
SEM - 0.1nm / 100 000x

I'll give you a question in a second.

really?? I thought TEM and SEM was 1nm

I also thought SEM was x300000

[ohmyBEAUT]

Question for Axion - Define the term passive transport and explain one process which is passive. (5)

Question for anyone else - Explain the need for staining samples used in light microscopy and electron microscopy. (3)

[ohmyBEAUT]

(Original post by Axion)
really?? I thought TEM and SEM was 1nm

I also thought SEM was x300000

For the TEM/SEM resolution anything from 0.05 - 1.0nm is accepted.
For the magnification I'm not sure.