Genetics and Breeding Exam 2

Backcross

Mating of hybrid to a purebred of a parent breed

Frequency of the aa genotype with inbreeding is

q² + pqF

A composite breed is…

Originated from crosses of 2 or more breeds, then closed to unrelated stock

Which pair has a relationship coefficient of about 0.25

Half-Sib

Which system has HV^1 = 50% and HV^M = 100%

Backcross

What is an arrow diagram

A pedigree showing the flow of genes from ancestors to descendants

In the path formulas, Fca stands for

The inbreeding coefficient of the common ancestor

HV^P (paternal hybrid vigor) results from having

Crossbred sires

Which formula calculates hybrid vigor for a cross of breeds of A and B

(P_AB + P_BA/2) - (P_AA + P_BB/2)

Why do elite breeders use inbreeding

To concentrate favorable genes

It can also reveal genetic defects and decline the rate of response to selection

In the punnet square, the off diagonal cells sum to

HV retained

Inbreeding depression

The reverse of hybrid vigor, a decrease in performance of inbreds

What are the rules of the path method

Paths follow the arrows with no backtracking, the same individual appears only once, all possible paths should be included

Frequency of the AA genotype with inbreeding is

P² + pqF

A Backcross is the mating of a hybrid to

A purebred of a parent breed or line

The breeding coefficient F ranges from

0-1

HV% is hybrid vigor divided by the ___ then multiplied by 100

Mean of the purebred paternal lines

Which pair has a relationship coefficient of about 0.50

Sire and daughter and full sibs

In the inbreeding formula, n1 and n2 represent

Generations from the common ancestor to the sire and dam of X

Formula for the frequency of the heterozygous Aa genotype with inbreeding is

2pq- 2pqF

Which has a third breed included? Example C x HA, C x AH

HV^M

Definition of inbreeding

The mating of relatives

Paternal hybrid vigor

Hybrid vigor for the paternal component of a trait

2 breed specific

HV^I = 100%, HV^M=0%, low difficulty, high uniformity

3 breed specific

HV^I = 100%, HV^M =100%, low difficulty, high uniformity

Back cross

HV^I = 50%, HV^M =100%, low difficulty, high uniformity

2 breed rotation

HV^I =67%, HV^M =67%, medium difficulty, low uniformity

3 breed rotation

HV^I=86%, HV^M=86%, high difficulty, low uniformity

Composite

Variable HV^I and HV

^M of 40-80%, low difficulty, high uniformity

3 breed rotational

HV^I =100%, HV^M = 67%, high difficulty, medium uniformity