Author Topic: Biology Paper 1  (Read 9309 times)

Offline camel

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Re: Biology Paper 1
« Reply #30 on: June 05, 2009, 07:07:03 am »
@noemi n goin4dakill: letz b a bit more respectful here ppl... :)

n noemi yes i had my lit xam 2day....hope urs went well ;)

gud luck evry 1 4 da final week!  :D

Yeah sorry, that was mean. But i didnt mean it, shes my bf. Sorry thoughhhhhh
Yes, hope urs went well as well. What books did u do priceless?

 yes, lets be more respectful!!!

Offline cool_dude

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Re: Biology Paper 1
« Reply #31 on: June 05, 2009, 07:25:02 am »
i need markscheme for paper 1, nov 02..
hurry!

Offline kam

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Re: Biology Paper 1
« Reply #32 on: June 05, 2009, 07:47:00 am »
anyone has markschemes for old papers
need em urgently

Offline camel

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Re: Biology Paper 1
« Reply #33 on: June 05, 2009, 07:47:56 am »
NITROGEN CYCLE ANYONE PLEASE!!!!!

Offline sisler

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Re: Biology Paper 1
« Reply #34 on: June 05, 2009, 08:01:01 am »
hey ...
can anyone help me wid may/june2003 paper 1 - question 30  i dont understand how the answer is D

Offline kam

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Re: Biology Paper 1
« Reply #35 on: June 05, 2009, 08:04:01 am »
hey ...
can anyone help me wid may/june2003 paper 1 - question 30  i dont understand how the answer is D
pollen grains are plants sex cells
so they have half
the answer is B
even in mark scheme

Offline camel

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Re: Biology Paper 1
« Reply #36 on: June 05, 2009, 08:05:32 am »
hey ...
can anyone help me wid may/june2003 paper 1 - question 30  i dont understand how the answer is D
pollen grains are plants sex cells
so they have half
the answer is B
even in mark scheme

nitrogen cycle??!?!!

Offline 247sports

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Re: Biology Paper 1
« Reply #37 on: June 05, 2009, 08:05:46 am »
k nitrogen cycle very easy
first:
there is 79% of nitrogen in air which is inert i.e. doesnt react....but then some oragnisms need nitrogen to live so hw do they use it ??
this is done by the decomposers..turning nitrogen in a very usefull or in reactive form is calld nitrogrn fixation..
first lightin causes the nitrogen to react with oxygen to form its oxides..then they idssolve in rain and are washed into the soil where the decomposers convert it into nitarates or NH3....nw nitrogen-fixin bacteria they use nitorgen gas form the air n combine it with other sustances to make  nitrtes n other usefull compounds...there is another bacteria who does teh opposite it converts the nitrates into nitrogen gas....its calld denitifyin bacteria...
n also these bacteria they breakdown the waate of naimal into nitarates too
phew anewho hope this helps n i think this is enuf for nitrogrn cycle
   WHISH ME LUCK MY XAM IN 1 HR :s  



Offline Aodian

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Re: Biology Paper 1
« Reply #38 on: June 05, 2009, 08:24:48 am »
LUCK  ;D
Music is enough to last a lifetime, but a lifetime isnt enough for music..

ami tomake bhalobashi.. <3

Offline Feva

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Re: Biology Paper 1
« Reply #39 on: June 05, 2009, 08:32:38 am »
can someone explain transpiration ?

and the functoin on phloem?

Thank You

Offline sisler

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Re: Biology Paper 1
« Reply #40 on: June 05, 2009, 08:38:20 am »
hey ...
can anyone help me wid may/june2003 paper 1 - question 30  i dont understand how the answer is D
pollen grains are plants sex cells
so they have half
the answer is B
even in mark scheme
thx probably the markshceme i have is wrong

Offline Kim

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Re: Biology Paper 1
« Reply #41 on: June 05, 2009, 08:40:50 am »
can someone explain transpiration ?

and the functoin on phloem?

Thank You
transpiration is when the plant loses water throgh the leaves in the form of water vapour
it is reduced due to presence of the waxy cuticle but can not be stopped
their are 5 factors affecting transpiration
1-humidity
2-temperature
3-stomata
4-light intensity
5-surafce area

phloem is made of livivg cells arranged end to end with cross walls wid pores
it has nucleus and cytoplasm
its main function is the transport of sugars in the form of sucrose from ares of manufacture to areas of utilization
hope this helps
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Offline Feva

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Re: Biology Paper 1
« Reply #42 on: June 05, 2009, 08:53:25 am »
Thanks man  ;D

+rep

Offline kam

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Re: Biology Paper 1
« Reply #43 on: June 05, 2009, 08:55:38 am »
so if there was high humidity high temps etc
the rate of transpiration increases?

Offline camel

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Re: Biology Paper 1
« Reply #44 on: June 05, 2009, 08:57:35 am »
k nitrogen cycle very easy
first:
there is 79% of nitrogen in air which is inert i.e. doesnt react....but then some oragnisms need nitrogen to live so hw do they use it ??
this is done by the decomposers..turning nitrogen in a very usefull or in reactive form is calld nitrogrn fixation..
first lightin causes the nitrogen to react with oxygen to form its oxides..then they idssolve in rain and are washed into the soil where the decomposers convert it into nitarates or NH3....nw nitrogen-fixin bacteria they use nitorgen gas form the air n combine it with other sustances to make  nitrtes n other usefull compounds...there is another bacteria who does teh opposite it converts the nitrates into nitrogen gas....its calld denitifyin bacteria...
n also these bacteria they breakdown the waate of naimal into nitarates too
phew anewho hope this helps n i think this is enuf for nitrogrn cycle
   WHISH ME LUCK MY XAM IN 1 HR :s  

thank you, that helped :P