F215 - Revision thread 13th June 2011

OH CRAP i haven't done any revision. ****, im so screwed for this exam.
I wonder who's fault that is?
Maybe if I don't contribute anything and tell everyone on this thread like it's my freaking facebook page or twitter, the people that are actually trying to work will help me and it'll all be okay!

Didnt you go onto Uni? Or did you retake the year?

ok so confused again... book sez this

Genomes are mapped to identify which part of the genome that they come from. Information that
is already known is used, such as the location of microsatellites
Samples of the genome are mechanically sheared into smaller sections of around 100,000 base
pairs
These sections are places in separate Bacterial Artificial Chromosomes (BACs) and transferred to E.
coli cells. As the cells are grown in culture, many copies of the sections are produced- referred to as
Clone Libraries


I just dont understand it.... like "Genomes are mapped to identify which part of the genome that they come from."
everything is confusing me

can anyone just tell me in a simple way with all the key terms PLEASEE!

Hey dude, considering you've done the exam, can you tell me the brief order of genome sequencing?

Haha, sure

----

Plants respond to there enviroment to avoid predation and abiotic stress, so that they are able to photosynthesize effectively and survive.

Plants respond through tropisms, a tropism is a directional growth response of a plant determined by the direction of the external stimulus.

To produce a tropism, a plant produces growh hormones or plant growth substances. These are hormones which are released by specific parts of the plant to bind to target cells to initiate a response > due to the receptor having a complimentary shape for the hormone to bind to, and trigger an effect.

Auxins

-Produces in the apical bud(the apex) of the shoot tip in the plant
-Involved in cell elongation, stem elongation and also preventing leaf abcission.

Auxin is also involved in a phototrophic response, this response happens because, as light hits the plant, the apical bud produces auxins that are able to flow down the shaded side(the side of the plant that is not exposed to the sun). Auxin causes cell elongation by helping in the active transport of hydrogen ions into the cell wall, this allows optimum pH for expansioners to work, these expansioners are able to break the bonds between cellulose(which are going to be glycosidic bonds i believe) and so the plant is able to take in water, causing elongation.
This then means that the shoot bends towards a light source.

Auxins are also involved in apical dominance, the growing apical bud inhibits the groth of the lateral bud(side shoots) further down the plant. It's been tested experimentally, because if you remove apical bud of a plant, side shoots are able to grow. If you apply synthethic auxin once you've removed the apical bud, side shoots don't grow.

Gibberlinnins - need to know a bit about them, just that they cause internodal stem elongation which has been tested experimentally, by applying synthethic GA (gibberlillic acid) to dwarf varities of plants, your able to produce tall plants > this is useful in sugar cane crops, so GA is applied.


Leaf abcission/leaf fall in decidicous plants

This is caused by a variety of hormones.

-Auxin prevents leaf loss by acting on the cells of the abcission zone, but as the cell gets older, the auxin concentration decreases

-As auxin conc decreases, concentration of Ethene increases, working antagonistically - ethene causes enzymes (cellulase) to digest the cell wall of the cells in the abcission zone > which means the leaf seperates from the stem

-Cytokinins are also involved, they prevent leaf loss by making the cells in the abcission zone a sink for phloem transport, so get's a good supply of nutrients, e.g sucrose.

Commercial use of plant hormones

Auxins can be applied to fruit trees to prevent fruit from dropping early, auxin is also used as a herbicide as it causes cell elongation, and also increases the length of the stem > this means that the plant will need to take up more nutrients from which it can't get and so will die.

Auxins can be used as rooting powder, as they promote seed germination i think

Gibberlennins are used in the brewing process (forgot how)
Gibberlniegnegns are used to produce long internode crops e.g sugar cane

Cytokinins - can be applied to plants to prevent leaf fall

Ethene - can be applied to plants to allow them to fall earlier, this applies to bannanas which are sprayed with ethene, so when they are packaged and sold - they ripen.

that's all of plant responses done.. woo

What would you write for sliding filament model?

What would you write for sliding filament model?

About the Myosin Heads they bind to something* and then bend causing thin filaments to cross over thick filaments forming cross bridge.
Its a power stroke
you need atp
Tropomyosin tropnin

Can someone please fix my answer into words thanks

I think PCR will come up, definitely something on genetic engineering/gene therapy, galapagos islands look likely aswell, and succession.

Theres lots
Apoptosis
Sliding filament
brain
epistasis
gene theraphy
galapagos and humans
golden rice
few others but cant remember them