Top answers

Why do we vaccinate people - how does it work?

Vaccination is an important method used in healthcare to prevent people from getting certain diseases. Vaccines contain a dead or weakened ( attenuated) form of a pathogen, and the immune system responds to ...
ES
Answered by Ella S. • Biology tutor
4223 Views

Rationalising the denominator (Surds)

When asked to rationalise simple Surd (square roots that cannot be reduced to a whole number) fractions in the form a/√b we are aiming to remove the surd in the denominator (bottom).-------------------------...
GY
Answered by Galen Y. • Maths tutor
20717 Views

Explain the trend in ionisation energy down group 2? (3)

• down group 2 the number of protons increases therefore the nuclear charge increases (protons are found in the nucelus and have a +1 charge) • the number of shielding electrons increases ( each member down ...
FJ
Answered by Flora J. • Chemistry tutor
14507 Views

Explain the principles of PCR

The Polymerase Chain Reaction (PCR) is a method of DNA amplification in vitro. It consists of 3 stages - denaturation, annealing and extending. PCR relies on the use of a thermophilic Taq polymerase enzyme.
DB
Answered by David B. • Biology tutor
5501 Views

State the differences between introns and exons.

Introns and exons are parts of genes - exons code for proteins, whereas introns do not, ie: exons are converted into messenger RNA to allow these parts of the gene to then be transcribed into protein. Intron...
DB
Answered by David B. • Biology tutor
14352 Views