Wednesday, October 2, 2019
Parthenogenesis Essay -- Asexual Reproduction, Honeybees
Parthenogenesis is a natural form of asexual reproduction found most commonly in lower organisms and plants. Sometimes known as virgin birth, parthenogenesis, involves the growth of an individual without fertilization. Discovered in the 18th century by naturalist and philosopher, Charles Bonnet, parthenogenesis is a progressive evolutionary strategy that some organisms have employed to maintain a colony. Just as there are benefits to organisms that utilize parthenogenesis, like reproduction without the need of male gametes, there are costs, such as a decrease in genetic variation. In the intricate eusocial organization of honeybees, there are three social classes ââ¬âqueen bee, worker bees and drone bees. The queen bee, as the name entails, holds the superior position in the colony. The queen bee lays all the eggs in the colony, being the only bee with a set of completely developed ovaries and having life-long fertility (Back Yard Beekeepers Association n.d.). After only one mating flight were the queen mates with a couple male drone bees, she stores the sperm to later fertilizes some of the eggs. The eggs that get fertilized develop into female worker bees and the eggs that develop without fertilization produce male drone bees. Due to the high maintenance of both the colony and its products, i.e. honey, most of the bees in a hive are female worker bees. These worker bees carry on a magnitude of different tasks, not including reproduction, which is reserved only for the queen. The male drone bees are reserved for mating with the queen bee. Following copula tion, the drone dies because of their barbed sex organ (Back Yard Beekeepers Association n.d.). Scientists have been puzzled at how this multifaceted organization is maintained bu... ...nd genetic factors play a part in sex-determination (Slobodchikoff and Daly 1971). However in some other hymenopterans, parthenogenesis occurs via thelytoky parthenogenesis. There is a subspecies of honeybee, the Cape bee (Apis mellifera capensis), which is known to exhibit thelytoky, the production of diploid females from unfertilized eggs, eliminating the paternal genome (Heimpel and de Boer 2008). In the case of the Cape bee, the queen bee determines whether the eggs are haploid or diploid (Oldroyd et al. 2008). By thelytoky parthenogenesis, the Cape queen be can produce clones of herself (Oldroyd et al. 2008). Undergoing a different form of parthenogenesis gives Cape bees the advantage of creating males that could mate with other queens (Oldroyd et al. 2008), involving one individual for reproduction, and a decrease in gene loss (Slobodchikoff and Daly 1971).
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