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Biology

A Level

Describe the way in which the normal heart beat is initiated and controlled

The heart muscle is myogenic, which means that it can contract without any input from the nervous system. The stimulus for the muscle to contract originates from a group of specialised ca...

Answered by Sanskrithi S. • Biology tutor

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Some babies are born with a hole between the right and the left ventricles. These babies are unable to get enough oxygen to their tissues. Suggest why. (2)

A hole between the right and left ventricle means that blood would shunt from the left to the right ventricle as the pressure in the left ventricle is higher than in the right ventricle, leading to the mi...

Answered by Sparsh S. • Biology tutor

14190 Views

Sometimes, babies are born with a hole between the right and left ventricles of their heart. Why does this mean oxygenated blood cannot get around their bodies?

Higher pressure in the left ventricle (thicker wall, more contractile power) means that blood will cross from the left side of the heart to the right. This means that not as much oxygenated blood will be ...

Answered by Isobel H. • Biology tutor

3627 Views

Describe the process of PCR, including what is needed.

Chemical components needed: a DNA template, DNA polymerase enzyme, primers, nucleotides and reaction buffer.

Steps in PCR:

Denaturation 96 degrees, to seperate DNA strands

KS
Answered by Kavi S. • Biology tutor
3018 Views

How does the heart work to pump blood around the body?

Firstly, I would ensure that the student understands the basics concepts of atrial systole, ventricular syotle and diastole and the pathway of the blood around the heart. Then I would further explain the ...

Answered by Sophie C. • Biology tutor

3219 Views