Search our library of Biology questions

Top answers

Biology

All levels

Explain the transmission of a nerve impulse across a cholinergic synapse referring to action potentials. (6)

When an action potential reaches the terminal of a pre-synaptic cleft, voltage-gated calcium channels are stimulated to open, causing an influx of Ca+ ions in the pre-synaptic neuron. This infux of Ca+ io...

Answered by Sarah W. • Biology tutor

2007 Views

Describe how phagocytic white blood cells destroy bacteria. (4)

The phagocyte recognises antigens on the surface of the bacteria as foreign, causing it to be attracted to the bacteria. The phagocyte then engulfs the bacteria, forming a vesicle around it. Lysozomes fus...

Answered by Sarah W. • Biology tutor

11772 Views

Why does a base substitution in DNA not always result in the formation of non-functional proteins?

Protein structure is determined by amino acid sequence. Each amino acid is coded for by a triplet of RNA bases. These are transcribed from a DNA molecule. If a DNA base is substituted for another base, th...

Answered by Abby R. • Biology tutor

2758 Views