Ocr f215: 27/1/11

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Reply 140

ibysaiyan

Original post by SwordStream

I dunno mate. I've been at it since 10 this morning. Might catch some zeds soon.

Which topics have you still got to do ?

Reply 141

SwordStream

Most things on genetics - will go over in the morning

and muscles :frown:

Im off to bed X_X

Reply 142

ibysaiyan

Original post by SwordStream

Most things on genetics - will go over in the morning

and muscles :frown:

Im off to bed X_X

Gn.

Reply 143

mathsclown

Original post by ibysaiyan

Ty. I will go through them in a bit.They better be what the spec. wants us to know.
:tongue:

xD ehm have a look at your text book as well so your 100% alright with behaviour (^^,) 2 more points id like to add that i forgot :s-smilie:

ehm classical conditioning is involuntary and passive
operant conditioning is voluntary and active and is often referred to as trial and error learning
And thats everything from the heinemann book on behaviour

Lol feels weird this is the first bio exam i have ever revised for lool!!

(edited 13 years ago)

Reply 144

mathsclown

Original post by ibysaiyan

....

BTW what topics are you going over tonight?

Reply 145

ibysaiyan

Original post by mathsclown

BTW what topics are you going over tonight?

Hm... All of module four and then a quick rewind from the whole spec.
:P :P

Reply 146

mathsclown

Original post by ibysaiyan

Hm... All of module four and then a quick rewind from the whole spec.
:P :P

Yup same here, going to review it and do all the questions in the book :biggrin:

Reply 147

Summerdays

You can start aking me questiions now :smile:

Reply 148

peterlucas88756

Just finished revision FINALLY!! lol been up for the last 2 days straight learning the whole book Need sleep!!).

guys wot do u think the hardest module is in f215??

Reply 149

Summerdays

Original post by rtzj00

Just finished revision FINALLY!! lol been up for the last 2 days straight learning the whole book Need sleep!!).

guys wot do u think the hardest module is in f215??

Have you done any of the past papers or questions in the book/back of the heinmann book?

Reply 150

ibysaiyan

Original post by rtzj00

Just finished revision FINALLY!! lol been up for the last 2 days straight learning the whole book Need sleep!!).

guys wot do u think the hardest module is in f215??

Hmm tbh None are hard.. for module one genetics practice more on past papers.. other than that meh :/

Reply 151

Summerdays

Fell free to pot questions and I will try my best to answer them :smile:

Reply 152

ibysaiyan

Original post by Summerdays

Fell free to pot questions and I will try my best to answer them :smile:

LOL you are awake... :P I have muscles and animal behavior to finish.IDK which questions ons to think of.. hmm ooo yea gibberlins mary jones book doesn't have much on it.What do you know about it ?
All I know is that GA shows it's effect by gene expression.It binds onto protein receptors in the cells which in chain of reaction activate DELLA protein.This protein breaks down into a transcription factor which transcripts a gene for rapid growth of stem.

(edited 13 years ago)

Reply 153

ibysaiyan

Right I will start with tropism.
Tropism is a directional growth response to a stimulus.A plant shoot exhibits positive phototropism while the root shows negative phototropism.
Movements which don't depend on the direction of stimulus,are reversible and happen due to changes in cell turgidity are called nastic movements.

Phototropism is where plant growth occurs due to light.Auxin is the plant hormone involved in the elongation of stem.Light falling on the un-shaded are phophorylates photo-tropins.Phototropins are protein light receptors which abosrb blue light.As a result of phosphorylation an auxin gradient is formed flowing through un-shaded area to shaded.This is caused because transporter proteins are either activated as such they work more harder on one side than the other or that there are more number of them.Auxins bind onto the cell membrane receptors.In doing so the hydrogen ion conc. is fluxed,more h+ ions stay in resulting lower Ph.This activates enzyme which breaks through the cell walls/causing them to lose.Water enters by osmosis causing cells to increase in size.This effect is permanent.
Auxin is made at the tip of plants/germinating seed - Coleoptile.

Reply 154

ibysaiyan

outline the role of hormones in leaf loss in
deciduous plants;
Leaf loss/abscission is caused by the following plant growth regulators:
Auxin,Ethene, Abscisic acid

In a young leaf leaf loss does not occur because they produce plentiful of auxin.Auxin itself inhibits plant loss.As the leaf ages,auxin concentration decreases.This makes the leaf sensitive to ethene.Ethene production increase which inhibits auxin production.This change in concentration produces Abscisic layer "made of thin walls" which is broken down by enzymes.Prior to breakage a protective tissue is made by the plant called suberin to prevent pathogen entry.

describe how plant hormones are used
commercially

Ethene:Is used to ripen fruits hence fruits can be harvested early and made to ripe before the point of sale.

Auxin:Is used as a herbicide for some species of plants because it passes through the transporter proteins but don't go through the different set of outgoing t. proteins.The plant dies as a result of this.
Is used to produce seedless plants without the pollination of flower.

Gibberlins : Causes rapid growth of stem.In sugar cane this causes more productivity of sucrose.
Increases the size of fruit.
Is used in the brewing industry for the conversion of barley into alcohol.

Apical dominance is when the apex of the shoot grows and due to which lateral bud's growth is inhibited.
Auxins are involved here AGAIN.

At the tip of the shoot called apical meristem is where auxin is produced.Cells here constantly divide.Auxin goes down due to gravity.As it accumulates at the nodes on the lateral buds,it inhibits their growth.
Two experiments to prove it are:
1) Place a growing shoot upside down,you'll notice that apical dominance doesn't occur because auxin can't go against gravity.
2)Cut the top of the shoot (terminal bud),place synthetic auxin.Apical dominance takes place.

DONE........................ Now off to muscles xD xD

Reply 155

ibysaiyan

Grrrr nervous system is such a pain......

Reply 156

ibysaiyan

How much info do we need to know on biceps/triceps ?

Reply 157

SwordStream

Too much for my liking. Yet to go over muscles.

Reply 158

ibysaiyan

Original post by SwordStream

Too much for my liking. Yet to go over muscles.

I am almost done with muscles... man... I hope ALL THIS INFO STAYS INTACT GRRR I REALLY WISH EXAM WAS LIKE IN ERMM 3 HOURS... :P Oh well.. Once I am done i will do past papers... quickly and then a quick skim through genetics...

Reply 159

ibysaiyan

Original post by SwordStream

Too much for my liking. Yet to go over muscles.

Okk this is all what the book says on these muscles:
Biceps and triceps are antagonistic muscles.When one contracts other relaxes.The contraction of biceps gets the radius,ulna closer to the scapula.This is called flexing.Contraction of triceps gets them apart and this called extension. :s-smilie: