How does polyploidy occur in animals?
Polyploidy is the heritable condition of possessing more than 2 complete sets of chromosomes [Comai, 2005]. This condition can arise as a result of genome duplication(s) within a species (autopolyploidy), or from hybridization of 2 different species (allopolyploidy).
Why is there no polyploidy 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.
Do animals exhibit polyploidy?
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.
What do you understand by polyploidy?
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.
What do you understand by polyploid?
polyploidy, the condition in which a normally diploid cell or organism acquires one or more additional sets of chromosomes. In other words, the polyploid cell or organism has three or more times the haploid chromosome number.
What are the causes of polyploid?
Mechanisms of Polyploidy Polyploids arise when a rare mitotic or meiotic catastrophe, such as nondisjunction, causes the formation of gametes that have a complete set of duplicate chromosomes. Diploid gametes are frequently formed in this way.
What are two advantages to being polyploid?
There are three obvious advantages of becoming polyploid: heterosis, gene redundancy (a result of gene duplication) and asexual reproduction. Heterosis causes polyploids to be more vigorous than their diploid progenitors, whereas gene redundancy shields polyploids from the deleterious effect of mutations.
What are the advantages of polyploidy?
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.