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How do electrical impulses control contraction of the heart?

Electrical impulses from the SAN (sinoatrial node) spread across the atria walls to cause contraction. The impulses then pass to the ventricles via the AVN (atrioventricular node) after a short delay to allo...
JA
Answered by Jack A. • Biology tutor
3025 Views

Explain the concept of recessive and dominant alleles

Firstly it is always good to relate such a concept with an example that is easily remembered and therefore easily applied. Alleles refer to alternate forms of the same gene, which code for a particular trait...
JC
Answered by Juliette C. • Biology tutor
6387 Views

Why is an action potential an all or nothing process?

An action potential is the signal neurons use to communicate with each other. It is caused by the rapid opening of sodium channels and influx of sodium ions. Because at rest the inside of the neuron is negat...
GG
Answered by Gemma G. • Biology tutor
9458 Views

Explain what happens when there is a mutation in a gene whereby 2 bases are deleted ?

As there are 2 bases which are deleted a frameshift will occur at the site of the mutation. This means that all other amino acids coded for by the genes after the point of mutation will be different. This is...
KT
Answered by Kevin T. • Biology tutor
3711 Views

Describe the role of RUBISCO in plants and evaluate the importance of RUBISCO in the Calvin Cycle? (8 Marks)

combines CO 2 with { ribulose bisphosphate / RuBP } two molecules of { glycerate 3-phosphate / GP } RUBISCO is important for the Calvin Cycle because: It is an enzyme SO it lowers the activation energy for a...
JO
Answered by John O. • Biology tutor
9938 Views