Why is mule not a species?
A species is a group of organisms that can interbreed and create viable offspring. In other words, a species can have babies that can have babies too. This is why a mule is not really a new species. When a donkey and a horse get together, they produce a mule.
What species is mule?
A mule is the offspring of a male donkey (jack) and a female horse (mare)….
| Mule | |
|---|---|
| Family: | Equidae |
| Tribe: | Equini |
| Genus: | Equus |
| Species: | E. africanus asinus♂ × E. ferus caballus♀ |
What is heterosis example?
Heterosis has been observed and, in some cases, harnessed in many diverse systems. Examples of interspecies crosses of mammals that produce heterotic phenotypes include the mule resulting from a cross between a male donkey and a female horse, and the liger resulting from a cross between a lion and a tiger.
What is meant by heterosis?
Heterosis refers to the phenomenon that progeny of diverse varieties of a species or crosses between species exhibit greater biomass, speed of development, and fertility than both parents. Various models have been posited to explain heterosis, including dominance, overdominance, and pseudo-overdominance.
What is pure line?
Medical Definition of pure line : a homogeneous line of descent: as. a : a group of closely related individuals of identical genetic constitution (as the offspring of a homozygous self-fertilized parent) : a line of descent theoretically realizable from the inbreeding of completely homozygous and comparable parents.
How do you get a pure line?
plant breeding Pure-line selection generally involves three more or less distinct steps: (1) numerous superior appearing plants are selected from a genetically variable population; (2) progenies of the individual plant selections are grown and evaluated by simple observation, frequently over a period of several years;…
Is pure line homozygous?
The concept of pure line was introduced by Johannsen (1). Repeated self-breeding approaches full homozygosity asymptotically. Several generations of self-fertilization are needed to obtain an acceptable pure line (97% of the genes that were originally heterozygous would have turned homozygous after five generations).
What are the main features of pure line?
3. Features of Pure-Line Selection:
- Homogeneous: All the genotypes of a pure-line are homogeneous i.e. genetically identical and phenotypically similar.
- Non-Heritable Variation:
- Highly Uniform:
- Selection is Ineffective:
- Narrow Adaptation:
- More Prone to New Diseases:
- Isolation of Pure-Lines:
- Sources of Variation:
Who gave pure line selection?
botanist W. L. Johannsen
What is backcross method?
backcross. A breeding method used to move one or a only a few desirable genes from an agronomically poor crop line to an elite line. This is done by crossing a donor parent to an elite line, and crossing offspring with the ‘desired gene(s)’ back to the elite parent.
What is pedigree selection?
Pedigree selection is a breeding method in which the breeder keeps records of the ancestry of the cultivar. The base population, of necessity, is established by crossing selected parents, followed by handling an actively segregating population.
Why pedigree method is important?
Excellent method for improvement of easily observable and high heritable characters. As pedigree record is maintained, information regarding inheritance pattern of characters can be obtained as and when required. Each plant can be traced back to its parent plant.
What are the important uses of pedigree selection?
Pedigree selection can be made more useful by giving all information good and bad about ancestors, including the collateral relatives. Pedigree selection is particularly useful for initial selection for traits that are expressed in only one sex. Such selections can be made early and inexpensively.