Genetics and Evolution Lecture 1

Question 1

What are conditional mutants?

Answer 1

Mutants that have a phenotype dependent on conditions

Question 2

What is plasmid rescue?

Answer 2

When you use microorganisms to identify the function of human genes

Question 3

What is the floral organ arrangement?

Answer 3

Sepals
Petals
Stamens
Carpels

Question 4

Saccharomyces

Answer 4

Budding yeast
Brewers yeast
Temperature sensitive mutants that do not progress through the cell cycle at a restrictive temperature
Single celled
Eukaryotic
Can be easily grown in the lab

Question 5

What is the cell cycle of budding yeast?

Answer 5

Diploid cell
Spindle fibre body duplication
Bud emergence
DNA replication
Nuclear migration
Spindle formation
Chromosome segregation and nuclear division
Cytokinesis
Two cells

Question 6

Mutagenesis

Answer 6

Screening for mutants that are rested at a particular stage of the cell cycle
Identifies the key genes required for the cell cycle
Mutagenise the DNA (e.g. chemicals or radiation) then look for mutant phenotypes
Some mutants are forced to stop which kills the cells because they can’t carry out the cell cycle properly
At the permissive temperature the growth of all mutants is comparable to wild-type conditions
In different temperatures, a cell will show their mutant phenotype

Question 7

What is a G1 phase cdc mutant?

Answer 7

Stops the cell cycle at the end of G1
Conditional mutant because this stop is due to restrictive conditions
This has determined the gene responsible for passing from G1 to S

Question 8

What do mutations required for progression between cell cycle phases cause?

Answer 8

They cause cells to arrest at a specific point in the cell cycle

Question 9

What are the key cell cycle checkpoints? (no explanation)

Answer 9

G1, S, G2, M

Question 10

What is an S phase cdc mutant?

Answer 10

At the restrictive temperature, mutations in genes required for progression from the end of S phase causes yeast to arrest at the end of S phase