VCE Biology Question Thread

[katiesaliba]

Does the swelling from inflammation result fr leaky capillaries or vasodilation which brings more blood to the site?

Also, what causes the itchiness from inflammation?

Histamine causes both inflammation (vasodilation, leaky capillaries) and itchiness.
Swelling is a result of the accumulation of fluid in tissues due to increased capillary permeability and vasodilation-at least, I would think so.

[soNasty]

cDNA & reverse transcriptase: are we meant to know about these?
So far all i know is that reverse transcriptase can produce an essentially perfect cDNA template from a mature mRNA strand, free of introns. This would be beneficial to insert into bacteria, as they lack certain restriction enzymes required to splice introns.

[shivaji]

cDNA & reverse transcriptase: are we meant to know about these?
So far all i know is that reverse transcriptase can produce an essentially perfect cDNA template from a mature mRNA strand, free of introns. This would be beneficial to insert into bacteria, as they lack certain restriction enzymes required to splice introns.

yes, and also that retroviruses use reverse transcriptase to convert their rna into dna, so they could "take over" the host

[olivia1497]

I'm really stuck on a question where it says
- How do GM crop intervene in the HUMAN evolutionary process?
I'm really confused about how they could affect human evolution specifically....
Thanks

[shivaji]

I'm really stuck on a question where it says
- How do GM crop intervene in the HUMAN evolutionary process?
I'm really confused about how they could affect human evolution specifically....
Thanks

Possibly only humans who could eat the GM crops and survive are selected for.
An example (though not GM) is with selective breeding, in which the the lactose tolerant individuals were at a selective advantage due to the consumption of milk, and this was selected for, hence affected human evolution.

something probably along the lines of that

[katiesaliba]

Did plants and hominins evolve in a parallel fashion, given the trends in jaw sizes?

[shivaji]

is signal transduction applicable for lipid based hormones?

[mahler004]

cDNA & reverse transcriptase: are we meant to know about these?
So far all i know is that reverse transcriptase can produce an essentially perfect cDNA template from a mature mRNA strand, free of introns. This would be beneficial to insert into bacteria, as they lack certain restriction enzymes required to splice introns.

Pedantic point - it's not restriction enzymes involved in splicing.

[Reus]

Pedantic point - it's not restriction enzymes involved in splicing.

However the splicing of 2 pieces of DNA together is done by endonuclease's.

[katiesaliba]

is signal transduction applicable for lipid based hormones?

Yep! Just without a second messenger

However the splicing of 2 pieces of DNA together is done by endonuclease's.

The splicing together of two DNA pieces is catalysed by ligases not restriction enzymes...isn't it?

[Reus]

Yep! Just without a second messenger

The splicing of two foreign DNA pieces to create recombinant DNA is catalysed by ligases not restriction enzymes...isn't it?

Yes of course! But the separate sources of DNA need to cut first by RE's then ligated - splicing for rDNA

[kk.08]

In simple terms explain how DNA codes for proteins.

This is what I answered, is it okay?

First transcription occurs in the nucleus, from where mRNA carries the message and translocates to the ribosomes in the cytoplasm, where translation occurs. Then the tRNA reads the mRNA message and an amino acid is added as each mRNA codon is read, hence producing proteins.

[katiesaliba]

Yes of course! But the separate sources of DNA need to cut first by RE's then ligated - splicing for rDNA

Yes I know, I just thought you meant that endonucleases spliced DNA together.


Any who, do we need to know about intron retention in gene regulation?

[Reus]

In simple terms explain how DNA codes for proteins.

This is what I answered, is it okay?

First transcription occurs in the nucleus, from where mRNA carries the message and translocates to the ribosomes in the cytoplasm, where translation occurs. Then the tRNA reads the mRNA message and an amino acid is added as each mRNA codon is read, hence producing proteins.

You might want to mention 'peptide bonds', 'primary structure of proteins being created' and the structure of tRNA - the anticodon of tRNA and the amino acid attached.

[kk.08]

You might want to mention 'peptide bonds', 'primary structure of proteins being created' and the structure of tRNA - the anticodon of tRNA and the amino acid attached.

Okay cool, thanks for the feedback!!