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A level Biology: Post your doubts here!

BeBeskii108

BeBeskii108

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Mohammed salik said:
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. :)
Click to expand...
Thank you
 
BeBeskii108

BeBeskii108

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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.
 
VelaneDeBeaute

VelaneDeBeaute

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BeBeskii108 said:
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.
Click to expand...
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.
 
daredevil

daredevil

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BeBeskii108 said:
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.
Click to expand...
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 *
 
thats_me

thats_me

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Wolfgangs said:
How to convert tRNA to DNA? How using those sequence base thing?
Click to expand...

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
 
roxylara

roxylara

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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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thats_me

thats_me

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roxylara said:
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.. :/
Click to expand...
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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