Turn on thread page Beta

OCR 2010 A2 Biology Unit 2 - Control, Genome and Environment watch

Announcements
    Offline

    10
    ReputationRep:
    http://www.wiley.com/college/pratt/0.../actin_myosin/ Great animation explaining muscle contraction - some of the stuff is a bit unnecesarry but its really helpful
    Offline

    14
    ReputationRep:
    (Original post by afhussain)
    ill try and do one for the other modules too so there is stuff for the entire unit
    Yea perty please. xD
    Offline

    0
    ReputationRep:
    is there anyway we can get all notes from posters (word doc, ppts, links, videos, animations etc)on one thread? It would make life so much easier for everyone when we are wanting notes for a specific topic from this unit
    • Thread Starter
    Offline

    0
    ReputationRep:
    (Original post by afhussain)
    is there anyway we can get all notes from posters (word doc, ppts, links, videos, animations etc)on one thread? It would make life so much easier for everyone when we are wanting notes for a specific topic from this unit
    no problem, i will sort out all the notes posted so far;p
    Offline

    14
    ReputationRep:
    (Original post by Remarqable M)
    no problem, i will sort out all the notes posted so far;p
    Cools...I havent started f212 revision yet :s of all modules I find it lame dull boring... I got 100.... <_<.. how is yours going?



    Anyhow to roll things on f215:We covered Plant growth Substances (or hormones although they differ/vary a lot! for reasons I will post later).
    My tutor first spoke about the significance of the top of a plant and so on was more of a history lesson but with bio mash-up.
    So I will summarize it compactly.
    Tropism:Is the growth of the plant or part of the plant in response to an external stimulus.

    We have various trops. Such as hydro-tropism,photo-tropism,geo-tropism,aero-tropism and others for pressure and so on. Cant remember the rest.

    So a plant shoot would exhibit +ve photo-tropism and the root -ve p.tropism.
    Same way root shows +ve geo.tropism while the rest of the plant -ve.
    Nothing complicated as of yet.
    Here is where thing get interesting....
    Various experiments were done starting from 1818 onwards by Darwin till I cant remember when.The basic idea behind it was to know about how and why do the plants grow to light at certain direction.
    Various attempts were made:
    Ones which I remember are:
    It was widely speculated to the top of the plant had something to do with the growth, this was proved by blocking the plants "top" or more commonly known as apex,covering it with a disc of .
    Basically auxins or also known as IAA (2,4-D) is made by the apex of the plant.These are the substances responsible for the growth of the plant (cell/stem elongation).So when sunlight falls say for example on the right side of the plant i.e stem, what happens is that the sun provides kinetic energy to these auxin particles to [COLOR="rgb(255, 0, 255)"]"diffuse[/COLOR]" from right side to the left (depends where the sunlight is directed) as a result of which you get large proportion of auxins onto the left side while right does hold but few.
    Auxins works by attaching into its receptors.These receptors are found in the cell-walls of the plant cells.When auxin combines with the receptor chain reaction occur within the cell-plant such that the cell walls of that region get stretched i.e elongate.(The only way a plant can grow is by either having cells reproduced or enlarging them.)So as a result of this plants left side bends to the right and this goes on depending on the orientation of the sun.
    Note: Sun-light does not destroy auxins as initially thought.

    Now comes Apical dominance:
    This phenomenon occurs in certain plants.One which does is your traditional chrsitmas tree. The structure of which goes of like you know how.
    So as we know the top (apex) of the tree produces auxin and we would expect it to go all right to the bottom but why do we see such a weird lateral pattern? We would expect the plant to grow in equal proportion throughout! but here is where things change a bit.The auxin concentration is the most at top- medium midway and low at the bottom.
    So we expect growth to be max on top and so forth but these tress have "terminal buds" which have receptors to allow IAA to sit on them.
    IAA causes inhibition of these buds .... so top has retarded growth(lol) and as we go down the concentration of IAA ... more an more growth.
    LOOL my tutor went on to talk about neighbors plants and ways to block your pervy- ol neighbor by spraying auxins (LMAO).


    So this completes stuff on auxins and tropism.Stuff to be posted: Giberrlins,cytokinens,some device which has no gravity and seed revolves around it (its to do with seed germination),and another seed germination related question interlinked with GA aka gibberlins.
    Offline

    0
    ReputationRep:
    Hey, I dont find the OCR textbook too useful for the power stroke/sliding filament mechanism so I have had to use different sources and animations in order to put my own version together; can somebody just check over and see if I have done it right?

    1) Myosin binding sites on the thick filament are exposed.
    2) When we want to contract a muscle, the sarcoplasmic reticulum releases calcium ions which then attach onto the troponin subunit of the thin filament; this in turn causes the tropomyosin coil on the thin filament to move, thus causing a binding site on the actin to be revealed.
    3) As a result, a crossbridge forms between the actin binding site and the myosin binding site.
    4) This crossbridge bends, causing the thin filament to slide over the thick filament; this is the power stroke.
    5) The myosin head of the thick filament then binds with ATP, thus breaking the crossbridge.
    6) The myosin head then moves backwards, hydrolysing the ATP into ADP and inorganic phosphate

    Is this info correct and have i got everything in the right order? Thanks for the input!
    Offline

    0
    ReputationRep:
    Ive just done a powerpoint on about 60% of Module 4 (the last odd 60%). I did the first 40% yesterday but my computer froze so unfortunately i lost it all.

    When i come back to this module at the end for revision i will finish it all off.

    This ppt covers, sliding filament model, behaviour, flight or fight etc

    Let me know if anything needs changing.

    Module 4.pptx
    Offline

    14
    ReputationRep:
    This is it guys/gals! times of the essence xD.....
    I got some really! Hard-mental blocking questions on genetics Which I did today.. will post them up later . Meanwhile ... Post questions xD
    Offline

    14
    ReputationRep:
    (Original post by afhussain)
    Ive just done a powerpoint on about 60% of Module 4 (the last odd 60%). I did the first 40% yesterday but my computer froze so unfortunately i lost it all.

    When i come back to this module at the end for revision i will finish it all off.

    This ppt covers, sliding filament model, behaviour, flight or fight etc

    Let me know if anything needs changing.

    Module 4.pptx
    Thanks again :O
    Offline

    1
    ReputationRep:
    Our teacher was away last week so we made notes on Hardy-Weinberg and genetic drift and stuff, but now she's made us a 30 page booklet on Hardy-Weinberg and genetic drift in ridiculous detail... we have 3 weeks left and still need to do genetic engineering :\
    Offline

    14
    ReputationRep:
    (Original post by Ziffachan)
    Our teacher was away last week so we made notes on Hardy-Weinberg and genetic drift and stuff, but now she's made us a 30 page booklet on Hardy-Weinberg and genetic drift in ridiculous detail... we have 3 weeks left and still need to do genetic engineering :\
    Ohs :/ we are left with muscle + behavior =}
    Offline

    14
    ReputationRep:
    So not in the mood to study :/ meh... is it just me? *yawns* even after a decent sleep of 8 hours.Forget it gonna do work tomorrow.
    • Thread Starter
    Offline

    0
    ReputationRep:
    it seems like the excitement for F215 has died out? :lol: I can't blame you for that F215 really is a pain in the neck!
    Offline

    1
    ReputationRep:
    Pretty much done Module 2. If anyone needs help i'd be happy to offer it!
    Offline

    14
    ReputationRep:
    (Original post by Remarqable M)
    it seems like the excitement for F215 has died out? :lol: I can't blame you for that F215 really is a pain in the neck!
    Hell it is man! <_< ... anyhow I am open to questions also I am so friggin lazy to post some interesting questions on genetics
    But I will do it tonight.Its gonna be just me and my pen <3 all night long.
    Offline

    14
    ReputationRep:
    (Original post by ViolinGirl)
    Pretty much done Module 2. If anyone needs help i'd be happy to offer it!
    Hi there oh... now whats in module 2 again :/?I do other book which differs from heinmanns. :/
    • Thread Starter
    Offline

    0
    ReputationRep:
    (Original post by ViolinGirl)
    Pretty much done Module 2. If anyone needs help i'd be happy to offer it!
    Describe and explain Polymerase chain reaction? :p:
    Offline

    14
    ReputationRep:
    (Original post by ibysaiyan)
    Hell it is man! <_< ... anyhow I am open to questions also I am so friggin lazy to post some interesting questions on genetics
    But I will do it tonight.Its gonna be just me and my pen <3 all night long.
    That sounds dirty :teehee:

    :p:
    Offline

    14
    ReputationRep:
    (Original post by Remarqable M)
    Describe and explain Polymerase chain reaction? :p:
    PCR: Is one of the sub-process in which a dna is re-synthesised in return to get greater quanitity of genetic material i.e the original subject dna is resynthesised to make more copies of it. :p:
    The steps are:
    First the dna which has the gene which we are after is put in a weakened state by which I mean the hydrogen bonds(interactions) between the base pairs are weakened.This leaves two single strands of DNA.
    In the next step: Primers are long with Free dna nucleotides are added i.e annealing of the dna.
    The last step is where polymerase is added as the temperature is optimum for it to work.
    The temperature for all the three states are:
    1)95C
    2)65C
    3)72c
    Also these enzymes have been collected from organisms living in hostile conditions as these work around 72C which is quite high :O i.e these are well adapted .
    Offline

    14
    ReputationRep:
    (Original post by nuttygirl)
    That sounds dirty :teehee:

    :p:
    Oops that blows. :p:
 
 
 
Reply
Submit reply
Turn on thread page Beta
Updated: May 29, 2014

University open days

  • University of Warwick
    Undergraduate Open Days Undergraduate
    Sat, 20 Oct '18
  • University of Sheffield
    Undergraduate Open Days Undergraduate
    Sat, 20 Oct '18
  • Edge Hill University
    Faculty of Health and Social Care Undergraduate
    Sat, 20 Oct '18
Poll
Who is most responsible for your success at university

The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE

Write a reply...
Reply
Hide
Reputation gems: You get these gems as you gain rep from other members for making good contributions and giving helpful advice.