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What species has been formed by polyploidy?

What species has been formed by polyploidy?

Introduction. Polyploidy is the heritable condition of possessing more than two complete sets of chromosomes. Polyploids are common among plants, as well as among certain groups of fish and amphibians. For instance, some salamanders, frogs, and leeches are polyploids.

Which of the following may result in polyploidy?

Polyploidy arises as the result of total nondisjunction of chromosomes during mitosis or meiosis. Polyploidy is common among plants and has been, in fact, a major source of speciation in the angiosperms. Particularly important is allopolyploidy, which involves the doubling of chromosomes in a hybrid plant.

What organism has the highest ploidy?

You might be surprised to learn that some species of ferns have over 1200 chromosomes. That’s over 26 times more chromosomes than humans’ measly 46! In fact, the world record holder for the most chromosomes is the fern Ophioglossum reticulatum with 1260 chromosomes!

What represents a polyploid organism?

Organisms that have more or less than the normal number of sets are aberrant euploids. Polyploids are individual organisms in which there are more than two chromosome sets. They can be represented by 3n (triploid), 4n (tetraploid), 5n (pentaploid), 6n (hexaploid), and so forth.

Does polyploidy result in a new species?

Alternatively, when the short-term challenges of genome shock can be overcome, polyploidy may result in establishment of a new species (neopolyploids). Subsequent stable persistence and diversification of polyploid lineages depends on the fitness effects and long-term evolutionary consequences of polyploidization.

What is an example of polyploidy in plants?

Examples of important polyploid plants used for human food include, Triticum aestivum (wheat), Arachis hypogaea (peanut), Avena sativa (oat), Musa sp. (banana), many agricultural Brassica species, Solanum tuberosum (potato), Fragaria ananassa (strawberry), and Coffea arabica (coffee).

Is polyploidy common in animals?

In fact, polyploidy exists across all major taxonomic animal groups and occurs even relatively frequently among some groups, particularly in fish and amphibians [Otto and Whitton, 2000; Mable et al., 2011].

Which organism has largest chromosomes?

The organism with the highest chromosome number recorded in to date is estimated to be 1,440 (or 720 pairs) found in the adder’s tongue fern Ophioglossum reticulatum.

Are there any polyploid animals?

Examples in animals are more common in non-vertebrates such as flatworms, leeches, and brine shrimp. Within vertebrates, examples of stable polyploidy include the salmonids and many cyprinids (i.e. carp). Some fish have as many as 400 chromosomes.

Why are polyploid plants larger?

Large cells are produced by increasing DNA content or ploidy, a developmental strategy employed throughout the plant and animal kingdoms. The wide-spread use of polyploidy during cell differentiation makes it important to define how this hypertrophy contributes to organogenesis.

Why is polyploidy less common in animals?

Muller hypothesized that polyploidy was less common in animals than in plants due to the presence of strongly dimorphic sex chromosomes whose segregation during meiosis in tetraploids leads to non-viable chromosome constitutions (Muller, 1925).

Why is polyploidy more common in animals?

As shown below, polyploidy may be rare among animals because they often possess a degenerate sex chromosome and common among plants because they rarely possess a degenerate sex chromosome. In general, the number of active X chromosomes per cell is half the autosomal ploidy level (Mittwoch 1967).