What is a polypoid in biology?
What is a polypoid in biology?
Definition. noun. (genetics) A cell or an organism containing more than two sets of homologous chromosomes.
What are the different kinds of polyploids?
Stebbins distinguished three major types of polyploids: autopolyploids, allopolyploids and segmental allopolyploids (Stebbins, 1947). In autopolyploids all genomes are identical or very similar and arise via genome duplication within the same species (Stebbins, 1947; Lewis, 1980).
Can humans be polyploid?
Humans. True polyploidy rarely occurs in humans, although polyploid cells occur in highly differentiated tissue, such as liver parenchyma, heart muscle, placenta and in bone marrow. Aneuploidy is more common.
What is a polypoid tumor?
A nonspecific term for any benign or malignant tumour with a polyp-like appearance, which can range from HPV-induced condylomas to papillary carcinomas.
What is polypoid disease?
The phrase “polypoid disease” is purely descriptive and does not indicate any definite etiology. Rather it signifies a manifestation of gastric disease by the appearance of something polyp-like.
Why is polyploidy important?
Polyploidy is a major force in the evolution of both wild and cultivated plants. Polyploid organisms often exhibit increased vigor and, in some cases, outperform their diploid relatives in several aspects.
What is polyploidy with example?
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.
Is polyploidy harmful?
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 is polyploidy useful?
In some cases, when the crossing between two species is not possible because of differences in ploidy level, polyploids can be used as a bridge for gene transferring between them. In addition, polyploidy often results in reduced fertility due to meiotic errors, allowing the production of seedless varieties.
What is the difference between a polyp and polypoid?
Any discrete lesion protruding into the lumen of gastrointestinal (GI) tract appeared at endoscopy is called as “polypoid lesion”[3]. However, a polyp is defined as a proliferative or neoplastic lesion of gastrointestinal mucosal layer[3].