Results are out! Find what you need...fast. Get quick advice or join the chat
Hey there Sign in to join this conversationNew here? Join for free

OCR Biology AS F211 May 2012

Announcements Posted on
Live webchat: Student Finance explained - on TSR from 2 - 3pm 17-09-2014
Got a question about Student Finance? Ask the experts this week on TSR! 14-09-2014
    • 0 followers
    Offline

    ReputationRep:
    yhh sure. that would help me revise
    you can start
    • 23 followers
    Offline

    ReputationRep:
    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.
    • 0 followers
    Offline

    ReputationRep:
    (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!
    • 1 follower
    Offline

    ReputationRep:
    (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)
    • 23 followers
    Offline

    ReputationRep:
    Does anyone have the recent january 12 F211 Paper? Please!!!
    • 0 followers
    Offline

    ReputationRep:
    (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
    • 102 followers
    Offline

    ReputationRep:
    • 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
    • 102 followers
    Offline

    ReputationRep:
    Describe the structure of ribosomes (1 mark)
    • 11 followers
    Offline

    ReputationRep:
    (Original post by Axion)
    Describe the structure of ribosomes (1 mark)
    do we need to know this?
    • 0 followers
    Offline

    ReputationRep:
    (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.
    • 102 followers
    Offline

    ReputationRep:
    (Original post by TaraBelle)
    do we need to know this?
    Yep.

    Ok I'll ask another one.

    List 3 functions of cystoskeletons
    • 0 followers
    Offline

    ReputationRep:
    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
    • 102 followers
    Offline

    ReputationRep:
    And here is one question you you BEAUT.

    list the resolution and magnifications of the light, TEM and SEM
    • 102 followers
    Offline

    ReputationRep:
    (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
    • 9 followers
    Offline

    ReputationRep:
    (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.
    • 0 followers
    Offline

    ReputationRep:
    (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.
    • 102 followers
    Offline

    ReputationRep:
    (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
    • 102 followers
    Offline

    ReputationRep:
    (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 :confused:

    I also thought SEM was x300000 :confused:
    • 0 followers
    Offline

    ReputationRep:
    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)
    • 0 followers
    Offline

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

    I also thought SEM was x300000 :confused:
    For the TEM/SEM resolution anything from 0.05 - 1.0nm is accepted.
    For the magnification I'm not sure.
Updated: May 23, 2012
New on TSR

Writing your personal statement

Our free PS builder tool makes it easy

Article updates
Reputation gems:
You get these gems as you gain rep from other members for making good contributions and giving helpful advice.