Top answers


How does vaccination prevent infection?

1) Dead/Inactive/Attenuated Microorganisms activate immune response 2) White blood cells produce antibodies 3) Antibodies kill microorganisms 4) This allows for a faster response during reinfection
HS
Answered by Hans S. Biology tutor
4808 Views

How do enzymes work?

Enzymes are molecules in the body that break down specific substrates which can then be used for energy or stored. An enzyme contains an active site that is complementary in shape to the substrate being brok...
EH
Answered by Emma H. Biology tutor
3108 Views

How do vaccinations work?

People are immunised against pathogens through vaccination - usually an injection. A vaccine is comprised of dead , inactive or weakened pathogen or virus. These act as antigens (foreign proteins) that the b...
RO
Answered by Rachael O. Biology tutor
5963 Views

The surface run-off of nitrate from agricultural fertiliser into freshwater ponds and lakes can cause the death of the fish. Explain how this happens.

This question crops up a lot and may be up to a five mark question, if you learn the key points and terms you can be confident of getting all the marks you can here! First of all, an algal bloom occurs which...
SM
Answered by Sarah M. Biology tutor
5486 Views

What is an enzyme?

An enzyme is a protein that act as a biologcal catalyst, meaning that they will activate a biological reaction. Enzymes are very specific and will work with a specific substrate. You can think of an enzyme a...
LJ
Answered by Laureen J. Biology tutor
6472 Views