What is Autopolyploidy and allopolyploidy?

Autopolyploidy is the containment of multiple copies of chromosomes in the same parent. Allopolyploidy is the containment of the multiple copies of chromosomes of different species. The main difference between autopolyploidy and allopolyploidy is the type of chromosome sets in their nucleus.

How is an Allopolyploid produced?

Allopolyploids are typically derived from hybridization between two (or more) distantly related species and combine divergent genomes with their own chromosome complements. The most common route to allopolyploid formation is via unreduced gametes, which have been identified in many plant taxa [3].

What is a Allopolyploid species?

Allopolyploid. Species with chromosome sets derived from interspecific hybridization and chromosome doubling. Hybrid. An individual that results from crossing between individuals from two or more populations, races, subspecies, species, etc., including individuals that are F1s, F2s, and the set of all backcrosses.

What is Allopolyploid in plants?

allopolyploid A polyploid organism, usually a plant, that contains multiple sets of chromosomes derived from different species. Hybrids are usually sterile, because they do not have sets of homologous chromosomes and therefore pairing cannot take place.

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[KEY]Are humans polyploidy?[/KEY]

Humans. Polyploidy occurs in humans in the form of triploidy, with 69 chromosomes (sometimes called 69, XXX), and tetraploidy with 92 chromosomes (sometimes called 92, XXXX). Triploidy, usually due to polyspermy, occurs in about 2–3% of all human pregnancies and ~15% of miscarriages.

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Is a mule an Allopolyploid?

Allopolyploidy is when organisms contain two or more sets of chromosomes that are from different species. Examples of allopolyploidy include the allohexaploid Triticum aestivum, allotetraploid Gossypium, and mules.

What is the role of Allopolyploid in evolution?

The polyploidy has played an important role in evolution of new varieties and species in nature. Angiosperms and Pteridophytes have very high numbers of polyploid species in nature. It is generally noted that with the increase in chromosome number the adaptability and variabilities of species increase progressively.

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[KEY]What is allopolyploid example?[/KEY]

The cell or the organism in allopolyploidy state is referred to as allopolyploid. Wheat is an example of an allopolyploid with six chromosome sets. For instance, a cross between tetraploid wheat Triticum (AAAA) and rye Secale (BB) would produce a hybrid progeny with a chromosomal composition of AAB.

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[KEY]Are Hexaploids sterile?[/KEY]

Triploids are usually autopolyploids. They arise spontaneously in nature or are constructed by geneticists from the crossof a 4x (tetraploid) and a 2x (diploid). The 2x and the x gametes unite to form a 3x triploid. Triploids are characteristically sterile.

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What is Autotetraploid?

: an individual or strain whose chromosome complement consists of four copies of a single genome due to doubling of an ancestral chromosome complement.

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[KEY]How common is Tetraploidy in humans?[/KEY]

Conclusions. Tetraploidy is an extremely rare, usually lethal form of chromosomal aberration.

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What is the difference between an Autopolyploid and Allopolyploid?

The main difference between autopolyploidy and allopolyploidy is that autopolyploidy is the containment of multiple sets of chromosomes that are derived from the same species whereas allopolyploidy is the containment of multiple sets of chromosomes that are derived from different species.

What happens if you have 69 chromosomes?

Three sets, or 69 chromosomes, are called a triploid set. Typical cells have 46 chromosomes, with 23 inherited from the mother and 23 inherited from the father. Triploidy occurs when a fetus gets an extra set of chromosomes from one of the parents. Triploidy is a lethal condition.

Is polyploidy fatal in humans?

Interestingly, polyploidy is lethal regardless of the sexual phenotype of the embryo (e.g., triploid XXX humans, which develop as females, die, as do triploid ZZZ chickens, which develop as males), and polyploidy causes much more severe defects than trisomy involving the sex chromosomes (diploids with an extra X or Y

Is polyploidy good or bad?

Though polyploidy is not common in animals, it is suspected that it might have played a role in the evolution, eons ago, of vertebrates, ray-finned fish, and the salmon family (of which trout are members). But on the whole, polyploidy is a dicey and often dangerous affair for animals.

Why are the offspring generated from interspecies crosses often sterile?

Mules, hinnies, and other normally sterile interspecific hybrids cannot produce viable gametes because the extra chromosome cannot make a homologous pair at meiosis, meiosis is disrupted, and viable sperm and eggs are not formed.

Are hybrid plants always sterile?

Plant hybrids are the result of sexual reproduction between plants from two different taxa or species. Not all plant hybrids are sterile, but many are. Hybrids commonly form in nature between closely related species, but humans also produce sterile hybrid plants intentionally for commercial purposes.

Can some hybrids reproduce?

In short, hybrid animals are infertile because they don’t have viable sex cells, meaning they can’t produce sperm or eggs. This is the case because the chromosomes from their different species parents don’t match up.

What is gigas effect?

The gigas effect is often attributed to a larger volume of nuclear DNA causing increased cell size that results in an overall increase in organ size; thus, polyploid plants often have larger flowers, leaves, pollen, seeds, and fruit, as well as more robust stems and an overall increase in plant size (e.g. Levin, 2002;

Why is polyploidy advantageous?

In summary, the advantages of polyploidy are caused by the ability to make better use of heterozygosity, the buffering effect of gene redundancy on mutations and, in certain cases the facilitation of reproduction through self-fertilization or asexual means.

What does polyploidy lead to?

Polyploidy can also be problematic for the normal completion of mitosis and meiosis. For one, polyploidy increases the occurrence of spindle irregularities, which can lead to the chaotic segregation of chromatids and to the production of aneuploid cells in animals and yeast.

Can a human have 49 chromosomes?

49,XXXXY syndrome is an extremely rare aneuploidic sex chromosomal abnormality. It occurs in approximately 1 out of 85,000 to 100,000 males. This syndrome is the result of maternal non-disjunction during both meiosis I and II. It was first diagnosed in 1960 and was coined Fraccaro syndrome after the researcher.

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[KEY]What is tetrasomic inheritance?[/KEY]

In tetrasomic inheritance, four copies of a linkage group rather than two (tetrasomy) assort two-by-two.

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What is maternal Disomy?

Uniparental disomy refers to the situation in which 2 copies of a chromosome come from the same parent, instead of 1 copy coming from the mother, and 1 copy coming from the father.

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[KEY]Which of the following is Allopolyploid Brassica?[/KEY]

Brassica juncea (brown mustard, 2n = 4 × = 36; genome AABB) is an allopolyploid species that originated from a spontaneous hybridization of Brassica rapa and Brassica nigra and contains many valuable traits.

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