Genetics Flashcards
Study of passage of traits from one generation to its offspring and unit of inheritance
Genetics
What is the component of the gene that controls inheritance
DNA
long, slender, threadlike structures found in the nucleus of a cell.
Chromosomes
Each chromosome carries hundreds of genes which are found at a fixed location. What is the location of the gene
Locus / loci
it has 23 pairs of chromosomes combining genetic material from the mother and father.
fertilized egg
Hide a paired gene’s characteristic
Dominant genes
Suppressed or hidden trait
Recessive gene
It is the result of the joint action of the genes. characteristic is controlled by that gene
Incomplete dominance
Example of incomplete dominant heterozygous
Roan
Set of boxes that form what is referred
Punnet square
Capital letter is used to indicate?
Dominant
Lowercase is used to indicate?
Recessive
It carries two different genes for particular characteristics (Aa)
Heterozygous
It carries indentical genes for a characteristic (AA aa)
Homozygous
It is an outward physical appearance of the animal
phenotype
It is the genetic makeup of an individual
Genotype
major management practice used to improve genetics in a breeding program.
Genetic selection
It involves breeding for one or two traits at a time. The selection process becomes limited and ineffective when selecting for more than two traits.
Tandem selection
practice that is widely used for many species. It eliminates less desirable traits by removing individuals
Culling
type of scoring system. Criteria are developed reflecting the desired qualities for the breeding animal. with a low score being best.
Selection index
it compares the pedigrees lists of an animal’s ancestors
Evaluating animals
It compares sire base on the performance of their offspring
Progeny test
It can be used to improve the genetic makeup of a producer’s stock
Artificial breeding methods
It can be utilized after the right animal has been selected for breeding.
the genes of exceptional males and females can be spread more extensively than they would if natural mating was used.
artificial insemination (AI) and embryo transfer (ET)
It is a selecting a genetically superior sire for Al or a genetically superior female for ET.
Genetic improvement
Two types of breeding system
Straight breeding and cross breeding
It determines the offspring’s breed and its relationship to other offspring and to its Parents.
Breeding system
It involves the mating of two animals from the same breed. They used them in their operations to produce high quality animals.
Straight breeding
male and female are both purebred animals and are of the same breed. It results in a greater standardization of genetic material.
Purebred breeding
male and female are both purebred animals and are of the same breed. It results in a greater standardization of genetic material,
Purebred breeding
Parts ng straight breeding
- purebreeding
- inbreeding
- close breeding
- line breeding - outcrossing
- upgrading or grading up
It is used to improve genetic purity by further selecting for a desirable characteristic of that breed
Inbreeding
Type of breeding that shares more than one ancestor like sire and sister/brother
Close breeding
Type of breeding that is related animals is used to maintain a close genetic relationship to an outstanding ancestor.
Line breeding
Breeding that are of the same breed but different pedigrees.
Outcrossing
Breeding where purebred male is bred to a grade female, which has one purebred parent and one of a mixed or unknown breed
Upgrading
Slower overall improvement
Grading up
breeding of two animals from different breeds. May be both purebred male and grade female
Crossbreeding
evident when the offspring displays superior qualities in comparison in size, rate of growth and vitality
Hybrid vigor
It involves mating a female and male from different breeds.
Two-breed cross
ex.
Hereford cow to an angus bull
Breeding that involves mating of a crossbreed female to a male of a different breed.
Three-breed cross
Breeding that involves using males of different breeds for several succeeding generations of females, then repeating the series.
Rotational cross
involves the crossbred female being bred to a male that is of the same breed as one of the parents of the Female.
Backcrossing
involves depositing semen that has been previously collected from the male in the female reproductive tract.
AI
One advantage of AI
- since the sire does not need to be present for the breeding.
- allows collected semen to be frozen
Give some disadvantages of AI
- if mistake made when storing the semen for later use, it cannot be used to produce offspring.
- requires more time and labor to ensure pregnancy.
Advantages of ET
allows an animal to produce a larger number of genetically superior offspring
Can be mechanically divided to produce identical twins to
Disadvantages of ET
low pregnancy rate for frozen embryos implanted in surrogate mothers.
what the general management practices?
- Genetic selection
- Evaluating animals
- Artificial methods of breeding
What are the diff. Technics in genetic selections
- tandem selection
- culling
- selection index
