Edexcel 6BIO2 ~ 3rd June 2013 ~ AS Biology

Original post by mace0590

meaning the structure of plant n animal etc i guess

thanks

Reply 1463

Original post by billyfisher100

I reckon:

Not much HSW or practicals
Lots on mitosis phases
Root tip squash practical description or maybe tensile strength or tissue culture
RER/Golgi transport
Zoos
Stem cells
Mammalian fertilisation/adaptations or maybe plant fertilisation
Cell structure
Maybe a small question on cellulose structure

thaaanx i hope what u said wil b true :biggrin:

Reply 1464

badass_geek

1

Hey, does anyone have the January 2009 paper?

Reply 1465

[QUOTE="Vivaviolin77;42922245"]i feeel there might be a question on drawing two glucose moelcules togther[/QUOTE c c

whats ure expectation in general? :biggrin:

Reply 1466

Original post by The Monk

I can never seem together full marks on plant fertilisation. Have I missed anything out:
Grain has two nuclei.
Tube nucleus releases enzymes to digest through style to the ovule.
Generative nucleus travels down tube, splits into two haploid nuclei.
One nuclei fertilises the two polar nuclei to form the endosperm.
Other nuclei fertilises the egg to form the diploid zygote.

???

i found this:
In plants: In flowering plants, nuclei from the gametes also have to combine in the process of fertilisation.

•

fertilisation takes place in the embryo sac within the ovule

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the pollen grain germinates on the style

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a pollen tube grows down through the style towards the ovary, with its growth controlled by the tube nucleus.

•

the pollen grain contains two nuclei ( the tube nucleus and the generative nucleus

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on germination of the pollen, the generative nucleus divides to form two haploid gamete nuclei which move down the pollen tube.

•

the tube grows through a microscopic pore into the embryo sac and the two male gamete nuclei enter the sac.

•

one fuses with the egg cell and forms a diploid zygote

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the second fuses with two nuclei in the embryo sac called polar nuclei to form a triploid cell.

This diploid zygote divides to form the embryo. The triploid cell divides to form the seed's storage tissue, endosperm.

Reply 1467

Kurraiyo

Original post by Vivaviolin77

multipotent - cells differentiate, but can form a number of other tissues. it is not pluripotent because it cannot give rise to many cell types

hope this helps

No I mean in my textbook it says the blood drained from the umbilical source contains PLURIPOTENT stem cells and not multipotent ones.
But the notes say that multipotent stem cells are found in cord blood. Which one is right? :/

Reply 1468

gold_

Original post by The Monk

I can never seem together full marks on plant fertilisation. Have I missed anything out:
Grain has two nuclei.
Tube nucleus releases enzymes to digest through style to the ovule.
Generative nucleus travels down tube, splits into two haploid nuclei.
One nuclei fertilises the two polar nuclei to form the endosperm.
Other nuclei fertilises the egg to form the diploid zygote.

???

mention that the pollen tube passes through a small gap called the micropyle and then into the embryo sac

also mention that when pollen tube reached the embryo sac, the tube nucleus disintegrates and the tip of the pollen tube bursts.

i think mentioning in the end that this is double fertilisation can gain you a mark. Not so sure though but no harm in trying.

Reply 1469

[QUOTE="mace0590;42922369"]

Original post by Vivaviolin77

i feeel there might be a question on drawing two glucose moelcules togther[/QUOTE c c

whats ure expectation in general? :biggrin:

looking at the all the past papers ive seen and sat
same as the above person who has given a list
i feel that they might be a question on the for and against stem cell research maybe
and maybe beta gatalisadase (spelling completely wrong)

Reply 1470

Original post by Vivaviolin77

i feeel there might be a question on drawing two glucose moelcules togther

whats ure other expectations :smile:

Reply 1471

am sorry guys if i do something wrong but first time here n its pretty confusing :frown:

Reply 1472

[QUOTE="Vivaviolin77;42922454"]

Original post by mace0590

looking at the all the past papers ive seen and sat
same as the above person who has given a list
i feel that they might be a question on the for and against stem cell research maybe
and maybe beta gatalisadase (spelling completely wrong)

alrite kwwl all the best :smile:

Reply 1473