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- https://bio.libretexts.org/Courses/Coastline_College/Book-_Cells_-_Molecules_and_Mechanisms_(Wong)/14%3A_Cell_Cycle/14.08%3A_MeiosisTo maintain the proper number of chromosomes in each generation, the gametes each contribute one set of chromosomes, so that the fertilized egg and all other cells in the organism have two sets of chr...To maintain the proper number of chromosomes in each generation, the gametes each contribute one set of chromosomes, so that the fertilized egg and all other cells in the organism have two sets of chromosomes — one from each parent. The purpose of meiosis, and its primary difference with mitosis, is not generating daughter cells that are exact replicates, but generating daughter cells that only have half the amount of genetic material as the original cell.
- https://bio.libretexts.org/Courses/Thompson_Rivers_University/Principles_of_Biology_II_OL_ed/02%3A_Evolution/2.03%3A_The_Origin_of_Species/2.3.02%3A_SpeciationSpeciation is an event in which a single species may branch to form two or more new species.
- https://bio.libretexts.org/Bookshelves/Introductory_and_General_Biology/Biology_(Kimball)/07%3A_Cell_Division/7.04%3A_PolyploidyThis page discusses polyploidy, the condition of having more than two sets of chromosomes, mainly observed in plants like wheat and sugar cane. It can occur naturally through errors in gamete formatio...This page discusses polyploidy, the condition of having more than two sets of chromosomes, mainly observed in plants like wheat and sugar cane. It can occur naturally through errors in gamete formation or be induced artificially. Polyploidy can lead to speciation, with hybrids often sterile while polyploid plants remain fertile. Although rare in animals, some instances, such as a tetraploid rat, have been recorded.
- https://bio.libretexts.org/Bookshelves/Introductory_and_General_Biology/Principles_of_Biology/03%3A_Chapter_3/21%3A_Introduction_to_Evolution/21.02%3A_Formation_of_New_SpeciesConsider the two owls: in the north, the climate is cooler than in the south; the types of organisms in each ecosystem differ, as do their behaviors and habits; also, the hunting habits and prey choic...Consider the two owls: in the north, the climate is cooler than in the south; the types of organisms in each ecosystem differ, as do their behaviors and habits; also, the hunting habits and prey choices of the southern owls vary from the northern owls.
- https://bio.libretexts.org/Bookshelves/Cell_and_Molecular_Biology/Book%3A_Cells_-_Molecules_and_Mechanisms_(Wong)/15%3A_Cell_Cycle/15.08%3A_MeiosisTo maintain the proper number of chromosomes in each generation, the gametes each contribute one set of chromosomes, so that the fertilized egg and all other cells in the organism have two sets of chr...To maintain the proper number of chromosomes in each generation, the gametes each contribute one set of chromosomes, so that the fertilized egg and all other cells in the organism have two sets of chromosomes — one from each parent. The purpose of meiosis, and its primary difference with mitosis, is not generating daughter cells that are exact replicates, but generating daughter cells that only have half the amount of genetic material as the original cell.
- https://bio.libretexts.org/Courses/Gettysburg_College/01%3A_Ecology_for_All/06%3A_The_Evolution_of_Populations_and_Species/6.05%3A_Formation_of_New_SpeciesAlthough all life on earth shares various genetic similarities, only certain organisms combine genetic information by sexual reproduction and have offspring that can then successfully reproduce. Scien...Although all life on earth shares various genetic similarities, only certain organisms combine genetic information by sexual reproduction and have offspring that can then successfully reproduce. Scientists call such organisms members of the same biological species.
- https://bio.libretexts.org/Courses/Ouachita_Baptist_University/Reyna_Cell_Biology/09%3A_(T3)_Cell_Cycle/9.08%3A_MeiosisTo maintain the proper number of chromosomes in each generation, the gametes each contribute one set of chromosomes, so that the fertilized egg and all other cells in the organism have two sets of chr...To maintain the proper number of chromosomes in each generation, the gametes each contribute one set of chromosomes, so that the fertilized egg and all other cells in the organism have two sets of chromosomes — one from each parent. The purpose of meiosis, and its primary difference with mitosis, is not generating daughter cells that are exact replicates, but generating daughter cells that only have half the amount of genetic material as the original cell.
- https://bio.libretexts.org/Bookshelves/Introductory_and_General_Biology/Biology_(Kimball)/07%3A_Cell_Division/7.05%3A_EndoreplicationThis page discusses endoreplication, a process of DNA replication during the S phase without mitosis or cytokinesis, found in some animal and plant cells. Variants include replication with mitosis but...This page discusses endoreplication, a process of DNA replication during the S phase without mitosis or cytokinesis, found in some animal and plant cells. Variants include replication with mitosis but no cytokinesis and multiple rounds of replication without new nuclei. This can cause polyploidy or polyteny, the latter evident in Drosophila larva, where polytene chromosomes allow for gene amplification and increased expression.
