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Biology

A Level

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
2561 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

2828 Views

Can you explain the different valves of the heart and why they are important?

The heart consists of 4 chamber; left and right atria, plus left and right ventricles. The right atria recieves deoxygenated blood from the superior and inferior vena cava, delivering blood from the head ...

Answered by Radi D. • Biology tutor

2556 Views

Outline the "Sliding Filament Theory" of muscle contraction.

In the resting state, the myosin heads have a partially hydrolysed ATP molecule (ADP + Pi) giving them potential energy. When there is an influx of calcium ions as a result of sarcolemma depolarisation, t...

Answered by Sohail M. • Biology tutor

6385 Views

How do alveoli create a surface for efficient gas exchange?

This kind of question is extremely common in A level biology, they want you to explain a system and apply your knowledge of biological principals to it.

To understand alveoli we need to understand ...

Answered by Matthew C. • Biology tutor

7518 Views