Top answers

Describe what occurs at a neuromuscular junction during transmission of a nerve impulse

When an action potential arrives at the presynaptic terminal of a neuromuscular junction, the depolarisation stimulates voltage-gated Ca2+ channels to open, and calcium ions flow into the neurone. This flood...
JK
Answered by Julia K. • Biology tutor
3538 Views

Why does the thermal stability of Group 2 carbonates increase down the group?

Going down the group, Group 2 carbonates decompose at increasingly higher temperatures.This is because the Group 2 metal ion radius/size increases down the group while the charge stays the same.This means th...
SB
Answered by Saibhan B. • Biology tutor
16410 Views

In mutations, what are the possible ways in which the DNA can be modified to make the proteins from which it is produced, non-functional or inactivated?

Protein production by the ribosome ultimately depends on the triplet sequence of DNA. Each triplet codes for one amino acid, thus, alterations in this triplet code will change the amino acid if it codes for ...
Answered by • Biology tutor
2273 Views

How does a nerve impulse cross a neuromuscular junction

When an action potential arrives at the junction, the depolarisation causes voltage-gated calcium channels to open resulting in the influx of calcium ions in to the pre-synaptic neurone. This triggers the mo...
EM
Answered by Elke M. • Biology tutor
2565 Views

Describe and explain how the alveoli are adapted to facilitate effective gas exchange in the lungs.

The alveoli have a number of adaptations for effective gaseous exchange. Firstly, they have a very large surface area to volume ratio ; the combined surface area of the alveoli is approximately 50-75m 2 - la...
Answered by • Biology tutor
9990 Views