Search our library of A Level questions

Top answers

All subjects

A Level

Explain the post-transcriptional changes that occur in mRNA before translation.

After DNA has been transcribed into mRNA but before is it is translated into it's polypeptide amino acid chain, post-transcriptional changes take place.DNA, and therefore its corresponding mRNA are made u...

Answered by Ellen C. • Biology tutor

3546 Views

Describe the Working Memory Model

The use of the word ‘describe’ tells you that in this question all you need to do is explain the working memory model, and it does not require you to evaluate it in any way. The important thing is to make...

Answered by Sophie T. • Psychology tutor

3546 Views

Describe the differences in internal morphology that can be seen between a Nautilus and Ammonite

in nautiloids septal necks are retrosiphonate (point towards the protoconch / centre OR away from the aperture)in ammonoids septal necks are mainly prosiphonate (point towards the aperture OR away from th...

Answered by Victoria G. • Geology tutor

1794 Views

Describe how phagocytosis of a virus leads to the secretion of an antibody against this virus antigen.

Phagosome/vesicle fuses with lysosome;(Virus) destroyed by lysozymes/hydrolytic enzymes;Peptides/antigen (from virus) are displayed on the cell membraneHelper T cell/TH cell binds to the antigen (on the a...

Answered by Victoria G. • Biology tutor

3407 Views

Suggest and explain two ways the cell-surface membranes of the cells lining the intestine may be adapted to allow rapid transport of nutrient

Membrane has increased/large surface area for (fast) diffusion/facilitated diffusion/active transport/co-transport;Large number of protein channels/carriers (in membrane) for facilitated diffusion;Large n...

Answered by Victoria G. • Biology tutor

3989 Views