ged 15

Question 1

mendelian traits are

Answer 1

single gene (monogenic) with high penetrance

Question 2

complex traits (multifactorial/quantitative)are

Answer 2

polygenic/ may genes with low penetrance

often strongly influenced by environment

Question 3

mean

Answer 3

centre of the distribution

Question 4

variance

Answer 4

spread of values around the mean

Question 5

threshold traits

Answer 5

continuous genetic and environmental factors with a threshold above which a trait/disease is present

Question 6

formula for total phenotypic variance Vp

Answer 6

genetic variance + environmental variance

Vg + Ve

Question 7

heritability formula

Answer 7

h^2 = Vg/Vp

Question 8

high heritability eg 0.9 means

Answer 8

the phenotypic variance is largely due to genes

Question 9

what is the relatedness of monozygotic twins

Answer 9

r=1

Question 10

what is the relatedness of non identical dizygotic twis

Answer 10

r=0.5

Question 11

concordance

Answer 11

the probability that if one twin is affected the other twin is also affected by a trait

Question 12

if concordance was 1 what would this mean

Answer 12

of one twin is affected the other twin is always affected

Question 13

linkage equilibrium

Answer 13

each haplotype is present t the frequency expected from the allele frequencies

Question 14

linkage disequilibrium

Answer 14

some haplotypes are present at a higher or lower frequency than expected

Question 15

what are haplotypes

Answer 15

closely linked SNPs on the same chromsoem