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A level Biology: Post your doubts here!

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This is what i could think of....
The palisade mesophyll cells are adapted for photosynthesis. They have a thin cytoplasm densely packed
with chloroplasts, which can move around the cell on the cytoskeleton to regions of greatest light intensity.
The palisade cells are closely packed together in rows to maximise light collection, and in plants adapted
to low light intensity there may be two rows of palisade cells. :)
Thank you
 
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Can somebody please explain why prometers need to be transferred along with desired genes in gene technology? All I know is they initiate transcription. Except that I have no idea.
 
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Can somebody please explain why prometers need to be transferred along with desired genes in gene technology? All I know is they initiate transcription. Except that I have no idea.
Well according to a 'crammed' definition, they are the DNA sequences which are the binding sites for RNA Polymerase and the accessory proteins (transcription factors). Without promoters, the mRNA won't be transcribed from a DNA molecule.
 
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Can somebody please explain why prometers need to be transferred along with desired genes in gene technology? All I know is they initiate transcription. Except that I have no idea.
Ummm.... I'll give this a try... u see if this is right.

u know how genes are switched on and off? well if we do not transfer the promoters with the gene then the gene will just be there and not work. e.g. if it is an insulin prduction gene then it will not start producing insulin until it is switched on. the promoters switch on these genes.

can u confirm from anywhere if my answer is right? *I hope to God it is ryt :`) :p *
 
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How to convert tRNA to DNA? How using those sequence base thing?

tRNA has the anti-codons which are complementary to the codons on mRNA
mRNA is formed from DNA (mRNA is complementary to the DNA template)
According to base pairing:
( in case of DNA) A forms bonds with T
( in case of RNA) A forms bonds with U
(For RNA & DNA both) C forms bonds with G
Example :If we have the anti-codon on tRNA: UGC
the codon of mRNA (where the tRNA will bind) : ACG
the sequence of DNA( from which the mRNA was formed) : TGC
 
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Can someone help me on how to do the table and can someone show me where the viral particle is because I thought I measure it but I'm getting the wrong answer.. :/
 

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Can someone help me on how to do the table and can someone show me where the viral particle is because I thought I measure it but I'm getting the wrong answer.. :/
1.Here you just need to match the codons in fig6.1 with the aminoacids in the table6.1
as GUG is valine, CAC is histidine, CUG is leucine ......
the sequence will be: val-his-leu-pro-glu-glu-lys-ser-ala
2.The viral particle i think it should be one of the two with the dark areas in the middle
(Make sure to convert the length to nm)
For the actual size= size of the virus/Magnification
 
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Q2:- number of primary consumers will be more in summer as the number of producers will be more... in the graph we have B n D that shows almost the same curve... but as no. of primary consumers r always less than no. of producers so the ans is D

Q11:- The walls of alveoli n capillaries r moist in order to prevent friction n bursting of the walls...it has nthng with gaseous exchnge n the ans is C

Q27:- for repairing a complete tissue is to be repaired not a single cell..

Q30:- As frm DNA, RNA is formed n then protein is formed then the ans is amylase... (all enzymes r globular protein in nature)
 
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