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In contrast, an individual where each cell contains genetic material from two organisms of different breeds, varieties, species or genera is called a hybrid. [3] Another way that chimerism can occur in animals is by organ transplantation, giving one individual tissues that developed from a different genome.
Having multiple sets of chromosomes is called polyploidy. Polyploidy is usually fatal in animals where extra chromosome sets upset fetal development, but is often found in plants. [17] A form of hybrid speciation that is relatively common in plants occurs when an infertile hybrid becomes fertile after doubling of the chromosome number.
A few animal species and many plant species, however, are the result of hybrid speciation, including important crop plants such as wheat, where the number of chromosomes has been doubled. A form of often intentional human-mediated hybridization is the crossing of wild and domesticated species.
The list of organisms by chromosome count describes ploidy or numbers of chromosomes in the cells of various plants, animals, protists, and other living organisms.This number, along with the visual appearance of the chromosome, is known as the karyotype, [1] [2] [3] and can be found by looking at the chromosomes through a microscope.
Hybridization without change in chromosome number is called homoploid hybrid speciation. It is considered very rare but has been shown in Heliconius butterflies [83] and sunflowers. Polyploid speciation, which involves changes in chromosome number, is a more common phenomenon, especially in plant species. [citation needed]
In species that use the XY sex-determination system, parthenogenetic offspring have two X chromosomes and are female. In species that use the ZW sex-determination system the offspring genotype may be one of ZW (female), [28] [29] ZZ (male), or WW (non-viable in most species, [31] but a fertile, [dubious – discuss] viable female in a few, e.g ...
An image of multiple chromosomes, taken from many cells. Plant genetics is the study of genes, genetic variation, and heredity specifically in plants. [1] [2] It is generally considered a field of biology and botany, but intersects frequently with many other life sciences and is strongly linked with the study of information systems.
Allopolyploid species - a polyploid hybrid species where the two chromosome sets are derived from different parent species. Backcrossing - crossing of a hybrid with one of its parent species. Extrinsic incompatibilities - Environment-dependent reproductive barrier.