2-Variation & Genetics Of Animal Breeding Flashcards
What can be explained as the selective crossing of domestic animals that have desirable qualities resulting in improved offspring?
Animal breeding
What are translated as breeding values for a number of interesting traits
qualities
What is an interbreeding group of animals within a species with some identifiable common appearance, performance, ancestry or selection history?
breed
What are matings between animals of different breeds or lines?
Crossbreeding
What resulted in a wide variety of breeds within domesticated species, each adapted for particular purposes?
Selective breeding
What type of breeding is used to enhance desirable traits, such as:
In tropical countries, a local cattle breed with high tick
resistance is crossed with an exotic breed with high
production to create animals that have moderate
production and resistance to ticks
Crossbreeding
What is a key reason for crossbreeding in livestock. It is most beneficial for traits with low heritability, such as fertility and health, which are difficult to improve through selective breeding alone.
Heterosis (hybrid vigor)
occurs when crossbred offspring outperform the average of their parent breeds in traits such as size, growth rate, and fertility
Heterosis (Hybrid Vigour)
What type of animal breeding effect is stronger when the parent breeds are more genetically dissimilar
Heterosis
What occurs when two related individuals mate, increasing the likelihood of homozygosity (receiving the same allele from both parents). This happens because related animals share common ancestors, who pass on the same alleles to multiple generations
Inbreeding
Causes of Inbreeding in Animal Breeding:
- INBREEDING DUE TO GENETIC DRIFT (INEVITABLE INBREEDING)
- INBREEDING DUE TO NON-RANDOM MATING (EVITABLE INBREEDING)
What leads to a loss of genetic diversity over time, causing an increase in homozygosity? This is inevitable because it happens by chance when certain alleles disappear from a population.
Genetic drift
- Intentional mating of closely related animals (e.g., father-daughter or sibling matings) increases the likelihood of offspring receiving the same allele from both parents.
- This results in higher homozygosity and inbreeding but is reversible if breeders switch to random mating.
- Unlike genetic drift, this does not cause permanent loss of genetic diversity unless continued over many generations.
INBREEDING DUE TO NON-RANDOM MATING (EVITABLE INBREEDING)
Advantage: The main benefit of ? is that it allows the desirable characteristics of a bull or other male livestock to be passed on to more progeny more quickly than through natural mating. A single bull can produce over 10,000 calves annually via?
artificial insemination
What has been used to help with the reproductive success and conservation of threatened or endangered species?
Artificial insemination
What involves mating individuals with desired traits to increase the occurrence of those traits in a population. The focus is on isolating and propagating genotypes responsible for qualities that are desirable to humans (economically or aesthetically), not necessarily beneficial for the organism in its natural environment
Selective breeding
What leads to changes in the frequency of gene-associated traits within the population. These changes in gene frequencies are considered a form of evolution, making this breeding a driver of evolutionary processes.
selective breeding
If between-breed variation is small, selection within a breed may be enough to improve traits over time. This means breeders can focus on selective breeding programs without needing crossbreeding
UTILIZING WITHIN-BREED VARIATION
If between-breed variation is significant, selection within a breed may not be sufficient to improve certain traits.
CROSSBREEDING WHEN BETWEEN-BREED VARIATION IS LARGE
What ensures that future breeding programs have genetic resources to respond to market demands and climate change?
Conserving diverse breeds
WHAT IS THE SCIENTIFIC STUDY OF THE MECHANISM OF HEREDITY AND VARIATION?
GENETICS
WHAT ARE DETERMINE ELEMENTARY UNITS TRANSMITTED BETWEEN GENERATIONS IN UNIFORM PREDICTABLE FASHION
HEREDITARY CHARACTERISTICS
EACH UNIT CALLED ? MUST SATISFY AT LEAST TWO ESSENTIAL REQUIREMENTS:
1. that it is inherited in such fashion that each descendant has a physical copy of the material
2. that it provides information to its carriers in respect to structure, function and other biological attributes
GENE
Who introduced the term “genetics”?
William Bateson
