what is the difference between apomixis and parthenogenesis
Answers
Answered by
2
Parthenogenesis (agamogenesis): A haploid or diploid egg cell develops into an embryo. Contrary to some authors, parthenogenesis does not always result in genetically identical clones. If the haploid cells are formed by normal meiosis (as in the queen honeybee), crossing over during Prophase I of meiosis may result in some genetic variability. Crossing over is discussed later on this page. If the unfertilized eggs develop from mitotic oögenesis (without the reduction division of normal meiosis), then their offspring will be identical clones of each other.
Agamospermy in plants: An embryo arises from tissue surrounding the embryo sac. If this involves cells of the nucellus or inner integument it is called a nucellar embryo. Nucellar embryos are chromosomally identical to the sporophyte parent. They are essentially clones of the female tree. Apomictic seeds allow propagation of choice edible fig cultivars (female trees) without the transmission of viruses through cuttings. Mangosteen seeds (Garcinia mangostana) typically contain nucellar embryos and are used to propagate clones of this delicious tropical fruit tree.
Agamospermy in plants: An embryo arises from tissue surrounding the embryo sac. If this involves cells of the nucellus or inner integument it is called a nucellar embryo. Nucellar embryos are chromosomally identical to the sporophyte parent. They are essentially clones of the female tree. Apomictic seeds allow propagation of choice edible fig cultivars (female trees) without the transmission of viruses through cuttings. Mangosteen seeds (Garcinia mangostana) typically contain nucellar embryos and are used to propagate clones of this delicious tropical fruit tree.
Similar questions