Quantitative Inheritance

Question 1

Qualitative trait ( discontinuous) vs quantitative (continuous trait)

Answer 1

Qualitative - few easily distinguishable phenotype
Height of pea plant

Quantitative - range of phenotype
Kernel coat
Skin colour
Human height
Arise dur to polygenic condition and environmental conditions
Non allelic genes are involved

Also k/as polygenic inheritance

Question 2

Polygenic inheritance types of alleles

Answer 2

Additive (produce pigment)
Non additive (no pigment)

Question 3

Ratio of polygenic inheritance when genes at 2 loci cause additive effect

Answer 3

1:4:6:4:1

Question 4

Formula for nonof gene pairs involved

Answer 4

Ratio of F2 progeny expressing extreme phenotype=1/4^n

Question 5

Phenotypic varience

Answer 5

Vp=V(envi) + V(genetic) + V(interaction of genotype and environment)

Question 6

Heretability

Answer 6

It tell the proportion of phenotypic variation that attributes to genetic variation at particular environment

Question 7

Narrow and broad sense heretability

Answer 7

Broad= H^2= Vg/Vp
Vg=Va+Vd+Vi

Va= additive varience
Vd dominance varience
Vi epistasis varience

If H^2= 1 envi has no impact
H^2= 0 env has major impact

Narrow= h^2=V(additive)/Vp