Lecture 13

Question 1

How can when a mutation occurs influence phenoype?

Answer 1

If a mutation occurs, then all cells that come from that cell will also carry the mutation, therefore if they occur early in development there will be a large patch of mutated cells, and if they occur later then there will be a small patch of mutated cells

Question 2

What is the difference between prototrophs and auxotrophs?

Answer 2

Auxotrophs are mutants that cannot grow on a minimal medium as they will need one or more nutrients supplied
Prototrophs are ‘normal’ and can grow on a minimal medium

Question 3

What is the difference between a complex and minimal medium?

Answer 3

A complex medium contains all nutrients needed for life so both prototrophs and auxotrophs can grow
A minimal medium supplies only the necessary ingredients so only prototrophs can grow

Question 4

What are the different selection systems that can be used to identify auxotrophs?

Answer 4

Grow in a minimal medium, liquid culture the prototrophs will then grow will the auxotrophs will not, then the prototrophs can be filtered
This leaves auxotrophs which can be grown on complex medium and then identified by seeing which nutrient(s) they will not grow if the agar is deficient in