Author Topic: Edexcel BIOLOGY Doubts!!!!  (Read 133512 times)

Offline Ibiza279

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Re: Edexcel BIOLOGY Doubts!!!!
« Reply #195 on: June 07, 2010, 10:31:33 pm »
haha lol
nice
okay now me going to sleep have to wake up in about 7 hours lol
ok good night and Allah Hafiz

well takecare good nite sweet drms, n all the best fer tomorrow ! :)
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Offline haris94

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Re: Edexcel BIOLOGY Doubts!!!!
« Reply #196 on: September 08, 2010, 08:16:10 pm »
can some1 pls tell me the difference between collenchyma and sclerenchyma

Thanks
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nid404

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Re: Edexcel BIOLOGY Doubts!!!!
« Reply #197 on: September 11, 2010, 06:54:51 am »
Collenchyma- tissues found in the leaves, young stems and below the epidermis. Specialized cells- It consists of elongated cells with irregularly thickened walls. They are living.

Sclerenchyma- They are found in the mature parts of the plants and are dead at maturity. They have thick lignified walls and are impermeable to water and nutrients. They are specialized for transport of water and nutrients.


Offline MKh

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Re: Edexcel BIOLOGY Doubts!!!!
« Reply #198 on: October 12, 2010, 09:02:50 pm »
hey guyz...i hav a qn in Bio A2 unit 6b:
what is meant by a null hypothesis?? ???

Offline Deadly_king

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Re: Edexcel BIOLOGY Doubts!!!!
« Reply #199 on: October 13, 2010, 12:13:28 pm »
hey guyz...i hav a qn in Bio A2 unit 6b:
what is meant by a null hypothesis?? ???

The null hypothesis is often the reverse of what the experimenter actually believes; it is put forward to allow the data to contradict it.

So according to the experiment carried out, you should state a hypothesis which you'll contradict through the experiment. Hence you'll observe that indeed the null hypothesis is wrong.

Offline MKh

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Re: Edexcel BIOLOGY Doubts!!!!
« Reply #200 on: October 19, 2010, 08:54:24 pm »
hey Thanks buddy!!...JAZAK ALLAH :)

Offline Deadly_king

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Re: Edexcel BIOLOGY Doubts!!!!
« Reply #201 on: October 20, 2010, 05:07:45 am »
hey Thanks buddy!!...JAZAK ALLAH :)

Anytime  ;)

Offline Uchia

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Re: Edexcel BIOLOGY Doubts!!!!
« Reply #202 on: November 20, 2010, 04:17:06 pm »
could any person explain to me the DNA profiling/finger print method

Offline -Cornea

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Re: Edexcel BIOLOGY Doubts!!!!
« Reply #203 on: November 21, 2010, 08:11:42 am »
Hey.. Could anyone help me please with the condensation reaction between 2 fructose molecuoles i mean how the end product will look like :S and how can draw an unsaturated lipids :D
« Last Edit: November 23, 2010, 09:11:37 am by Pink Princess »
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Re: Edexcel BIOLOGY Doubts!!!!
« Reply #204 on: November 21, 2010, 03:53:03 pm »
where did u find tht q frm :/

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Offline Deadly_king

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Re: Edexcel BIOLOGY Doubts!!!!
« Reply #205 on: November 22, 2010, 07:12:51 am »
could any person explain to me the DNA profiling/finger print method

Well, that's very vast, you know. :-\

I'll advice you to read the application booklet for Chemistry, it goes in detail about it and has been very useful to me :)

If you need any other specific explanation about it, let me know ;)


Offline Deadly_king

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Re: Edexcel BIOLOGY Doubts!!!!
« Reply #206 on: November 22, 2010, 07:29:33 am »
Hey.. Could anyone help me please with the condensation reaction between 2 fructose molecules?  i mean how the end product will look like :S and how could i draw an unsaturated lipids :D

Two fructose molecules will undergo condensation reaction to form a disaccharide. You just need to draw the two fructose molecules side by side. Then the H from one molecule will combine with the OH of the other molecule to form the sugar along with the release of water. A 1,4 glycosidic bond is formed.

Watch this. It's the formation of sucrose from glucose and fructose. The same principle will be applied for your question. ;)

Unsaturated lipid are those which carbon-carbon double bonds in their hydrocarbon tails. So you just draw a normal lipid and add a C=C in its tail. ;)

The picture attached represents an unsaturated fatty acid. So you just have to include it in your lipid. :D

Offline Master_Key

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Re: Edexcel BIOLOGY Doubts!!!!
« Reply #207 on: November 22, 2010, 12:55:29 pm »
Two fructose molecules will undergo condensation reaction to form a disaccharide. You just need to draw the two fructose molecules side by side. Then the H from one molecule will combine with the OH of the other molecule to form the sugar along with the release of water. A 1,4 glycosidic bond is formed.

Watch this. It's the formation of sucrose from glucose and fructose. The same principle will be applied for your question. ;)

Unsaturated lipid are those which carbon-carbon double bonds in their hydrocarbon tails. So you just draw a normal lipid and add a C=C in its tail. ;)

The picture attached represents an unsaturated fatty acid. So you just have to include it in your lipid. :D

Saturated lipids are mainly fats and are solids. Unsaturated lipids are mainly found as oils.

Offline Deadly_king

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Re: Edexcel BIOLOGY Doubts!!!!
« Reply #208 on: November 22, 2010, 02:02:34 pm »
Saturated lipids are mainly fats and are solids. Unsaturated lipids are mainly found as oils.

Thanks for the precision dude. :)

But I think she only wanted to know how to draw the structure of unsaturated lipids ;)

Offline Master_Key

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Re: Edexcel BIOLOGY Doubts!!!!
« Reply #209 on: November 22, 2010, 02:25:25 pm »
Thanks for the precision dude. :)

But I think she only wanted to know how to draw the structure of unsaturated lipids ;)

Then I am sorry.