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Biology
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How is water reabsorption carried out in the kidney?

When water levels are low in the blood, osmoreceptors in the hypothalamus detect this change and trigger the posterior pituitary gland to release a hormone called ADH. ADH binds to receptors on the cell m...

JP
Answered by Jenna P. Biology tutor
2945 Views

Explain what an enzyme is and the lock and key hypothesis.

An enzyme is a biological catalyst that ensures important certain chemical reactions can take place. They speed up the rate of a reaction without being used up or changed. Maltase is an example of an enzy...

AH
Answered by Annie H. Biology tutor
9574 Views

Describe the principle of Polymerase Chain Reaction (PCR) and its application in laboratory setting.

Polymerase Chain Reaction is an in vitro method used to amplify DNA fragments. It consists of three main steps, which are: (1) denaturing, (2) annealing, (3) and extension. During denaturation, ...

Answered by Biology tutor
1497 Views

How is the cardiac cycle regulated by the heart itself?

The heartbeat is started at a specialised area of the right atrium, known as the sinoatrial node (SAN); the SAN sends out the waves of depolarisation, resulting in contraction of the card...

EB
Answered by Emma B. Biology tutor
3759 Views

Explain the main structures of a human cell.

A human cell is made up of:Cell Membrane: provides structure for the cell and controls what goes in and outCytoplasm: Jelly like liquid which contains the organellesNucleus: Contains DNAMitochondria: Make...

AC
Answered by Adham C. Biology tutor
2682 Views

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