breeding

Question 1

Locus

Answer 1

The position of a gene on a chromosome.

Question 2

Phenotype and Genotype

Answer 2

Phenotype: what we can see/measure
Genotype: genotic code, what alleles are present

Question 3

Alleles of 1 gene influence the actions of the alleles of the other gene-

Answer 3

Epistasis

Question 4

B gene-
A gene-
E gene-
G gene-

Answer 4

B gene- black
A gene- transforms black to bay
E gene- gives permission to B gene come to expression.
G gene-Grey

Question 5

Environment

Answer 5

All influences on a trait which are not genetic
- rearing, health, feed, training,

Question 6

Breeding value (EBV)

Answer 6

The mean genetic value of a individual as a parent for a trait.

Question 7

Monogenic and polygenic trait

Answer 7

Monogenic- expression determined by alleles of 1 gene( many genetic disorders)
Polygenic- expression determined by effects of many alleles.

Question 8

Repeatability

Answer 8

• the extent to which measurements on the same object under similar conditions correspond with each other. It indicates how accurate a trait can be established. if repeatability is low, heritability is also low.

Question 9

Reproducibility

Answer 9

• the relationship between measurements in different locations and/or by different persons.

Question 10

Additive genetic relationship (aij)

Answer 10

between 2 animals is the amount of DNA they share due to fact that they are related.

Question 11

The general interval

Answer 11

Is the average age of the parents at birth of their offsprings that in their turn will produce the next generation of breeding animals.

Question 12

What creates size of genetic diversity?

Answer 12

The presence of different alleles within the population
The frequency of alleles within the population

Question 13

Selection paths

Answer 13

Different selection activities at the same time within 1 population

Question 14

Immigration and emigration

Answer 14

immigration of new animal into population ( can increase genetic diversity) heterozygosity
emigration of an animal leaving the population (can decrease heterozygosity)

Question 15

What influences inbreeding (F)?

Answer 15

-inbreeding- the chance that an animal receives (a copy of) the same allele from both parents, increase because of inbreeding.
Influences-
the number of common ancestors, the distance to common ancestors.
Inbreed animals less healthy, live shorter, less fertile.

Question 16

Heterosis

Answer 16

• extent to which the performance of the crossbred is better than the average performance of 2 parents. Heterosis is caused by dominance, applies to heterozygous genes/ If many genes (polygenic traits) show dominance then offspring is better than average of both parents.

Question 17

Effects of heterosis

Answer 17

inbreeding( within a population) reduction heterozygosity, chance dominance effects down, inbreeding depression ( vitality t, fertility t), chance genetic defects up.
Crossbreeding (between population) increase heterozygosity, chance dominance effect up, heterosis ef. (vitality t, fertily t) chance genetic defects goes down.