Top answers

What hormones are involved in a pregnancy test and how does it work ? (6 marks)

After the human embryo implants in the uterus, the site of the developing placenta begins to produce a chemical called human chorionic gonadotrophin (hCG). hCG is a hormone that is found in the blood and uri...
EB
Answered by Ellie B. • Biology tutor
18717 Views

Why would a cell lyse when it's in water?

Lysis, or the bursting of a cell, happens because of a cell swelling excessively causing it to burst, due to the movement of water into the cell by osmosis. However, this isn't the case for all cells! Osmosi...
AA
Answered by Ashar A. • Biology tutor
20322 Views

What is the role of the nucleus?

The nucleus is the most important organelle of the cell and acts like a blueprint for how all the cells in your body function. The nucleus also acts as a vault to hold the DNA securely. The main function of ...
AD
Answered by Ameliya D. • Biology tutor
37203 Views

How does Haemoglobin work?

Haemoglobin is a protein made up of 4 sub-units. Each sub-unit has a molecule of un-oxygenated Iron. Oxygen covalently bonds to the Iron and is thereby carried by the blood as Oxy-haemoglobin. Oxy-haemoglobi...
CJ
Answered by Conor J. • Biology tutor
11308 Views

Define an organ

A group of similar tissues that work together to perform a particular function.
JJ
Answered by Jonathan J. • Biology tutor
4543 Views