week 2

Question 1

what happens due to meiosis

Answer 1

there is a recombination between the two parental genomes (only shuffles the pack does not create anything new)

Question 2

what is ‘crossing over’

Answer 2

As the DNA lines at the centromere similar DNA sequences from the paired chromosomes cross over one another.

Question 3

examples of genetic mutations

Answer 3

• single-base substitutions (transitions and tansversions)
• simple sequence repeat expansions and contractions
• transposable element insertions
• segmental changes

Question 4

what are mutations that have an effect called

Answer 4

deleterious

Question 5

what is a Mendelian disease and examples of some

Answer 5

the effect of deleterious genetic mutations

• cystic fibrosis
• huntington’s disease
• Tay-Sachs disease
• Haemophilia

Question 6

example of how to find genetic basis of a phenotype characteristic

Answer 6

assemble large groups of individuals with and without the trait and compare the frequency of different alleles

(using linkage & association studies)

Question 7

homozygous definition

Answer 7

having two copies of the same allele

Question 8

heterozygous definition

Answer 8

having one copy each of two different alleles

Question 9

dominant definition

Answer 9

expressing its phenotypic effect when one or more copies are expresses (DD)

Question 10

recessive definition

Answer 10

expressing its phenotypic effect only when two copies are present