Edexcel WBI02 ON 02/06/2014 (Biology Unit 2) IAL THREAD! NOT GCE

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Reply 40

saifulahmed

if i write two correct points for two marks and one incorrect point, do i get full marks?

Reply 41

Ripper Phoenix

Original post by saifulahmed

if i write two correct points for two marks and one incorrect point, do i get full marks?

normally from examiners reports they ignore the incorrect point! HOWEVER!!! you have to make sure that the incorrect one doesn't contradict either of the 2 correct ones .

Reply 42

Bazzir

Just a tip for you guys my teacher gave me,when a question says state ONE reason for blah blah blah, you are allowed to state more than one if you have space but keep in mind that they will mark the first one only. So if you wrote 2 points and your first one is wrong but the second is correct, you will lose the mark unless your first point is considered ''neutral'(neither wrong or correct). Thought Id share that cuz it helped me a bit :smile:

Reply 43

ih8school

Is lac operon included in the spec?

Reply 44

Ripper Phoenix

Original post by ih8school

Is lac operon included in the spec?

what on earth is that?

btw..do u know what sclerids are?

Reply 45

gabiguscott

Original post by Lassy96

Anyone mind explaining the diff between meiosis and mitosis?andd haploid and diploid cell?

Meiosis produces gametes which are haploid cells (only contain half a full set of chromosomes)
Mitosis is for growth and produces diploid cells (the full set of chromosomes)

Meiosis results in 4 daughter cells which are genetically different
Mitosis results in two genetically identical daughter cells

Meiosis goes through two divisions
Mitosis only goes through one division

Mitosis creates genetically different daughter cells because of two main reasons:
1) crossing over- this is when the alleles between a homologous pair swap. The point of crossing over is called the CHIASMA
2) independent assortment- which is when there is a random combination if chromosomes from the mother and the father.

Hope this helps :smile:

Reply 46

koko1234

Are we supposed to learn gametogenesis in plants and humans in details?

Reply 47

Ripper Phoenix

Original post by koko1234

Are we supposed to learn gametogenesis in plants and humans in details?

nope not at all

Reply 48

gabiguscott

Original post by Paras Agarwal

nope not at all

so we don't need to know gametogenesis?! Yay

Reply 49

Ripper Phoenix

Original post by gabiguscott

so we don't need to know gametogenesis?! Yay

yup its not there in the spec..you are supposed to know double fertilization in plants though

Reply 50

koko1234

Does any one have good revision notes for topic 4??

Reply 51

koko1234

Original post by Paras Agarwal

nope not at all

Thank god !!

Reply 52

ih8school

Original post by Paras Agarwal

what on earth is that?

btw..do u know what sclerids are?

Lactose operon. It's in the textbook, comes under gene expression.

Sclerids? No never heard of that.

Reply 53

Qura

Sclereids are a reduced form of sclerenchyma cells with highly thickened, lignified cellular walls that form small bundles of durable layers of tissue in most plants.

Reply 54

Qura

Sclereids are a reduced form of sclerenchyma cells with highly thickened, lignified cellular walls that form small bundles of durable layers of tissue in most plants.

Reply 55

Ripper Phoenix

Original post by Qura

Sclereids are a reduced form of sclerenchyma cells with highly thickened, lignified cellular walls that form small bundles of durable layers of tissue in most plants.

oo thanks

but its not in the spec right? lol ..

Reply 56

Qura

Original post by Paras Agarwal

oo thanks

but its not in the spec right? lol ..

Dont think so

Reply 57

Ripper Phoenix

quick question, what is the difference between a cellulose molecule and a cellulose microfibril? 3 marks

Reply 58

angelom1994

Original post by Paras Agarwal

quick question, what is the difference between a cellulose molecule and a cellulose microfibril? 3 marks

Hmmm that's a good question actually.

Cellulose molecule consists of B glucose monosaccharides joined together by 1,4 glycosidic bonds and each one is alternately inverted, cellulose microfibrils consist of individual cellulose molecules,they are cellulose chains arranged in a bundle which are laid down on the primary and secondary wall . Idk what else you could say ?