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Biology; Chemistry; Physics: Post your doubts here!

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Humid air contains a great deal of water vapour, so the concentartion gradient of water vapour between the surrounding air and the leaf is greatly reduced. And air can accept very little water vapour from plants.
Maybe you have seen the wrong paper.. My doubt was a question about the human heart... Thanks anyway... I have already got the answer I needed
 
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how shld study for biology as i am going to appear for may june 13 ...................pls help:confused:
Going through the same problem. :confused: I think the best way is to concentrate on your weaknesses just like
Try to do 10 years past papers and give importance to the areas which are difficult for you.
Mostly questions found difficult by students are on plants, genetics and applications of genetic engineering. also read on the skeletal system as it is included in the syllabus but not in many books.
 
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I am confused in how do we know about the allele in biology.. example look at June 2003 paper 2 Q3(a)(i)...........??? how do we know, me confused wd my own question!!
 
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I am confused in how do we know about the allele in biology.. example look at June 2003 paper 2 Q3(a)(i)...........??? how do we know, me confused wd my own question!!
I think you want to ask how do we determine which allele is recessive and which is dominant and similarly in a question how do we determine what organism has recessive or dominant alleles. Right? :confused:
Usually in questions, like the one you mentioned, the dominant allele (that shows a dominant character like walnut shape crown) is denoted by a capital letter, here Q while recessive is small 'q'. If a number of organisms is given, the ones with the recessive character will ALWAYS be homozygous for recessive while the ones with dominant characters can be heterozygous or homozygous dominant. This is because the recessive gene never reveals itself unless both alleles are same.
Get it? If not please feel free to say so.
 
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I think you want to ask how do we determine which allele is recessive and which is dominant and similarly in a question how do we determine what organism has recessive or dominant alleles. Right? :confused:
Usually in questions, like the one you mentioned, the dominant allele (that shows a dominant character like walnut shape crown) is denoted by a capital letter, here Q while recessive is small 'q'. If a number of organisms is given, the ones with the recessive character will ALWAYS be homozygous for recessive while the ones with dominant characters can be heterozygous or homozygous dominant. This is because the recessive gene never reveals itself unless both alleles are same.
Get it? If not please feel free to say so.
yes i think i got it......... thanks(y)
 
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thankyou very much but i could not find the cpmpiled version of chemistry with past papers etc
 
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Tell me about functional groupes????? chemistry;) define them too
and please tell their names and amount!!!!!
functional group is an element of group of elements combined to an organic molucule wich give it its specific characteristics!
each functional group gives rise to a new homologus series.....like in alcohols...the functioanl group is -O-H....n in carboxylic acids it is :
-C -O-H
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O
 
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Tell me about functional groupes????? chemistry;) define them too
and please tell their names and amount!!!!!
for alcohol it is -OH(hydroxy group)
for carboxyllic acid it is -COOH(carboxyl group)
for alkene it is C=C(carbon carbon double bond)
for ester it is -COO(ester group)

and a functional group is a special group of atoms that is responsible for the chemical reactions of a particular specie
 
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