Genetics and Breeding Flashcards

Vocabulary flashcards based on lecture notes about genetics and breeding.

The science that deals with heredity and variations.

Genetics

Animal Genetics

Branch of genetics that deals with principles of genetics exclusive to animals, whether feral or domesticated.

Law of Biogenesis

States that all living organisms come from other living organisms through reproduction, where parents transmit one-half of their genes through gametes to offspring.

Heredity

Transfer of traits or genes from each of two parents to the next generation; based on the transfer of genes from each parent.

Genes

Unit of heredity or inheritance that encodes a single protein.

DNA

Chemical coding for the genes.

Genome

Genetic code of an animal.

Histones

Proteins associated with the DNA in the chromosomes; they can influence gene expression.

Allele

A specific locus on a chromosome usually encoding a gene.

Candidate gene

One of the genes suspected in underlying the expression of a trait.

Chromosome

Consists of a long DNA molecule encoding multiple genes.

Cytogenetics

Field concerned with how the chromosomes relate to cell behaviour, particularly to their behaviour during mitosis and meiosis.

Epigenetics

Heritable changes in gene expression that are not encoded by DNA.

Epistasis

Where two or more genes interact.

Gene expression

The synthesis of RNA from the DNA template of the gene.

Genomics

Study of the entire genome (structural genomics) or comparisons between the genome of different species (comparative genomics) or transcription (functional genomics).

Heritability

Proportion of the total variation (genetic and environmental) in phenotype that is due to gene effects.

Genotype

Full collection of genes/DNA in a specific individual.

Phenotype

The set of observable characteristics or traits of an organism.

Quantitative trait loci (QTL)

Regions of DNA linked to the genes underlying a trait.

Selection index

An index of net merit weight traits based on their economic importance, heritability, and any genetic correlations existing in them.

Sex-linked genes

Nonreproductively related genes that are located on the X chromosome in mammals or Z in birds.

Transcription

Synthesis of RNA from the DNA template.

Translation

Synthesis of a polypeptide chain or protein from the RNA template.

Variation

Differences which exist between members of the same species, caused by a combination of genetic and environmental factors.

DNA

A double helix composed of two strands of an alternating deoxyribose and phosphate.

Nucleotide

The unit of DNA, comprised of one deoxyribose, one phosphate, and one base.

Codon

Three nucleotides that code for a specific amino acid.

Microsatellites

Repetitive segments of DNA scattered throughout the genome in noncoding regions between genes or within genes (introns).

Genetic marker

A gene or DNA sequence with a known location on a chromosome that can be used to identify individuals or species.

Comparative Genomics

Involves comparing the genomes of different species.

Mutation

A change to the genome of an animal.

Myostatin

A protein that inhibits muscle development.

Gene Ontology

Major bioinformatics initiative to unify the representation of gene and gene product attributes across all species.

Telomeres

Multiple TTAGGG tandem repeats at the end of chromosomes in at least higher vertebrates.

Dominant allele

One gene overshadows the other.

Recessive allele

The gene is overshadowed by the dominant gene.

Punnett Square

A square diagram that is used to predict the genotypes of a particular cross or breeding experiment.

Additive gene action

The effect of a gene when each additional gene enhances the expression of the trait by equal increments.

Dominance gene action

Deviations from additivity that make the heterozygote resemble one parent more than the other.

Overdominance gene action

When each allele at a locus produces a separate effect on the phenotype, and their combined effect exceeds the independent effect of the alleles.

Epistasis

Relationship between genes, where an allele of one gene hides or masks the visible output, or phenotype, of another gene.

Homozygous

A gene pair is one that carries two genes for a trait.

Heterozygous

A gene pair is one that carries two different genes (called alleles) for the trait.

Polygenic Inheritance

Traits that are heritable are based on multiple genes.

Breed

Specific group of domestic animals having homogeneous appearance, homogeneous behavior.

Strain

A genetic variant, a subtype or a culture within a biological species; group of animals within a breed with traits that distinguish them from others in the breed.

Line

Group of animals descended from appraised to a specific animal or source of genetic stock.

Mongrel

Mixed or unknown breed; also a dog of unknown parentage called a mixed-breed dog or mutt.

Cull

To remove from a herd or flock, usually because of age, low performance, or undesirable traits; set of animals rejected during the selection process.

Artificial insemination (AI)

Strategy increasing the number of genetically superior progenies from proven sires and dams.

Straightbreeding

Purebred breeding.

Inbreeding

Mating of closely related animals.

Line breeding

Animals closely related genetically but several generations apart.

Crossbreeding

Producing hybrid offspring, is when two or more different breeds are crossed.

Terminal cross

Between the parents of animals that ultimately will be slaughtered for meat.

Selection

Process in which certain individuals in a population are preferred to others for the production of the next generation.

Tandem Method

This method is used when genetic progress is aimed over a group of two or three traits one at a time.

Independent Culling Method

Each trait should meet a certain standard set for the purpose.

Selection Index

This method is the most applicable when selecting for more than one quantitative trait.

Pure breed breeders

Seedstock producers.

Commercial breeders

Producers.

SNPs

Single Nucleotide Polymorphisms, single base pair is different between animals of the same species.

Eumelanin

A type of melanin which produces black or brown colors.

Phaeomelanin

A type of melanin which produces orange/red colors.

Agouti

Banding of pigmentation along the hair shaft.

Colorpoint

A color pattern having dark colors on the face, ears, feet, and tail, with a lighter version of the same color on the rest of the body.

Adrenocorticotropic hormone

Stimulates the production of the stress hormone cortisol in mammals and corticosterone in birds and rodents.

Animal Cloning

A reproductive technology that allows an identical genetic twin to be derived from a previously existing animal at a later point in time.

Pedigree Chart

Diagrams that shows the occurrence and appearance of phenotypes of a particular gene or organism and its ancestors from one generation to the next.

Traits

Characteristics or attributes of an organism that are expressed by genes and/or influenced by the environment.

MC1R

Melanocortin receptor 1; The switch between producing eumelanin or pheomelanin.