Genetic models

Question

What is a genetic model?

Answer 1

A mathematical representation and simplification of biology

Answer 2

Are used as tools for breeding value estimation

Answer 3

In why phenotypes of some animals are more similer due to common genetics or common environment

Answer 4

- Prenatal phase/ from conception to birth
- From birth to weaning
- From weaning to reproductive matuirity
- Maturity and the rest of the animal's life

Answer 5

If many traits are determined by more than a single gene

Answer 6

Assumes that most traits are determined by an infenite number of genes, each with an infinitely small effect. This assumption reulst in a smooth bell-shaped distribution that can be described by the normal distrubution. This distribution comes with a number of rules that animal breading theory is built on.

Answer 7

That there is no dependency of the genetyope on the environment or vice versa

Answer 8

In variance component. The symbol for a variance coponent is sigma2 and the substrctipt indicates what type of variance component it is: P, G or E

Answer 9

- The epistatic effect: interaction between genes
- The dominance effects: interaction between alleles of the same gene
- Additive genetic effects of breeding values: all that is left after correcting for the interactive effects

Answer 10

Because they are difficult to estimate and not heritable

Answer 11

Indicates the random process in distrubting half te genetic material from each parent to their offspring

Answer 12

Aoffspring= 1/2sire+1/2dam+ MS

Answer 13

sigma2A= Var (A)= 1/4var(Asire)+1/4var(Adam)+ var (MS)

Answer 14

Indicates what proportion of the total phenotypic variation is due to genetic variation among individuals. In formula: h2= sigma2A/sigma2P

Answer 15

Because:
- it reflects the genetic variation for a trait in that specific population
- it is relative to the phenotypic variation for the trait in that specific population

Answer 16

The parent-offspring regression

Answer 17

A common environment is an environment that is shared with ohter during the development of the animal and that, therefore, is expected to have the samen influece on the development of all animals that shared a common environment The quality of an environment may have irreversible consequences if expierienced during development

Answer 18

P = A + C + E (C= common environmental effect_

Answer 19

Its size provides insight in the influence of the common environment on the variation in phenotypes observed

Answer 20

sigma2p= sigma2G+sigma2C+ sigma2E

Answer 21

c2= sigma2c/sigma2p

Answer 22

That the estimated value deviates in a particular direction

Answer 23

The effect of the environment created by the mother on the development of her offspring. The maternal effect is partly determined by the genes of the mother

Answer 24

Dsribes the effect that the phentypes of others have on the performance of an animal. Just like the maternal effect, the social effects are phenotypes that consist of combinations of genetics and environments of the other animals

Answer 25

P= Pd + sumPs= Ad+ Ed + sum(As+Es)
Ad= direct genetic effect of the animal itself
As= the social genetic effects of group members
Ed= the direct environment effect of the animal itsel
Es= the social environmental effects of group members

Answer 26

Multiple observations, are likely to be more similar that observations on different animals, because the same genetics is working on the thrait, and in some cases also part of the environmenttal influences

Answer 27

Is defined as the effect of the environment which is common to all repeated observations of an animal. The genetic model can be writtes as: P= A + Ep + Et where Ep is the permanent environmental effect and Et is the temporary environmental effect