Search our library of Biology A Level questions

Top answers

Biology

A Level

Describe the involuntary Relay Arc pathway of a nervous impulse, from the stimulus to the reaction

Stimulus eg (thorn prick) > Sensory Neurone > Relay Neurone (In Central nervous system) > Motor Neurone > Effector muscle (eg. in arm, to move hand away)Whiteboard would be use to draw pathway...

Answered by Isabella J. • Biology tutor

1383 Views

Describe the process of synaptic transmission with regard to action potentials

the action potential arrives at the terminal of the axon. The arrival of the action potential will cause voltage gated calcium ions to open allowing the calcium ions to rush into the axon terminal. The ar...

Answered by Ali H. • Biology tutor

1366 Views

Give two features of DNA AND explain how each one is important in DNA replication.

1. DNA is double stranded. This means that when the strands separate during replication, both strands can be used as templates to produce two new double stranded DNA ,each containing one of the origin...

Answered by Adam M. • Biology tutor

3035 Views

What are the types and effects of genetic mutations?

Insertion/deletion - one or more nucleotide pairs are put in/taken out of a sequence -> causes frameshift. Duplication - one or more bases are repeated -> leads to ...

Answered by Zofia K. • Biology tutor

1547 Views

Starting with mRNA in the cytoplasm, how are polypeptides produced?

The mRNA binds to a ribosome at the start codon. (1) The ribosome has a space for a tRNA molecule with a three base anticodon to bind to the complementary codon on the mRNA.(2) The tRNA brings the specifi...

Answered by Alice T. • Biology tutor

1940 Views