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What is reproduction?Reproduction is a biological process by which cells or living organisms give rise to offsprings. Species are maintained in existence through this vital process. Reproduction is not necessary to the life of an individual, yet it is a prerequisite for the continuity of any species.
What are the two basic types of reproduction?asexual and sexual. In asexual reproduction, offspring arise from a single parent even without special reproductive cells or organs. The new individual is a separated part of the parent organism. Sexual reproduction, however, involves the union of two nuclei from special cells, which are usually produced by two separate parents. Some organisms reproduce only asexually, others reproduce only sexually, and still others can reproduce by either of these methods.
Talk in general about asexual reproduction.Asexual reproduction (also known as agamogenesis) is the biological process by which an organism creates a genetically-similar or identical copy of itself without a contribution of genetic material from another individual (lack of genetic recombination). It is a form of reproduction which does not involve meiosis, gamete formation, or fertilization.
How is asexual reproduction performed?Asexual reproduction may be as simple as cell division, resulting in two separate individual cells, as in Prokaryotes and simpler Eukaryotes, or it may involve the production of spores, special reproductive cells, each capable of producing a new organism, common in Algae and Fungi. At a more complex level, as in higher plants (also reproduce sexually), asexual reproduction involves the formation of a complete multicellular individual, which becomes detached from its parent. This way of reproducing is called vegetative reproduction as it is accomplished without seeds or spores.
Talk about asexual cell division.Asexual reproduction involves only mitotic cell division, therefore each offspring has exactly the same hereditary information as its parent: each daughter cell receives an exact copy of the chromosomes of the mother cell (clones). Thus asexual reproduction results in stable characteristics within a species from generation to the next: the same chromosome number is retained from generation to generation. Asexual reproduction is efficient in that it is generally rapid and often results in the production of large numbers of identical offsprings.
Talk in general about sexual reproductionSexual reproduction is a biological process by which organisms generate heterogeneous offsprings (descendants) that have a combination of genetic material contributed from two different members of the species (typically one of each sex), thus leading to genetic diversity.
What are the characteristics of sexual reproduction?This type of reproduction is characterized by two processes. The first, meiosis, involves the halving of the number of chromosomes. The second process, fertilization, leads to the fusion of two gametes and the restoration of the original number of chromosomes.
Can plants reproduce sexually and asexually?Many organisms can reproduce sexually as well as asexually. Bryophytes, Pteridophytes and many plants are examples.
Talk about when plants that can reproduce sexually and asexually become asexually reproducing.When environmental factors are favorable, asexual reproduction is employed to exploit suitable conditions for survival such as an abundant food supply, adequate shelter, favorable climate, optimum pH or a proper mix of other lifestyle requirements. Populations of these organisms increase exponentially via asexual reproductive strategies to take full advantage of the rich supplied resources.
When do sexual/asexual plants reproduce sexuallyWhen food sources have been depleted, the climate becomes hostile, or individual survival is jeopardized by some other adverse change in living conditions, these organisms switch to sexual forms of reproduction. Sexual reproduction ensures a mixing of the gene pool of the species. The variations found in offspring of sexual reproduction allow some individuals to be better suited for survival and provide a mechanism for selective adaptation to occur. In addition, sexual reproduction usually results in the formation of a life stage that is able to endure the conditions that threaten the offspring of an asexual parent. Thus, seeds, spores, cysts or other “dormant or quiescent” and resistant form ensure the survival during unfavorable times and the organism can “wait out” adverse situations until a swing back to suitability occurs in order to carry on its asexual reproduction.