Asexual Reproduction versus Sexual Reproduction comparison chart. Asexual Reproduction. Sexual Reproduction. Number of organisms involved Asexual reproduction is reproduction that occurs without any interaction between two different members of a species. Cells divide using mitosis, in which each chromosome is copied before the nucleus divides, with each new cell receiving identical genetic information. Cell division in asexual and sexual reproduction Asexual reproduction is well suited for organisms that remain in one place and are unable to look for mates, in environments that are stable. It is usually used by simple organisms such as bacteria.
Asexual reproduction in : a caducuous phylloid germinating Asexual reproduction is a form of in which an creates a genetically-similar or identical copy of itself without a contribution of material from another individual. It does not involve , ploidy reduction, or fertilization, and only one parent is involved genetically.
A more stringent definition is agamogenesis, which refers to reproduction without the fusion of . Asexual reproduction is the primary form of reproduction for single-celled organisms such the , , and . However, while all reproduce asexually (without the formation and fusion of gametes), there also exist mechanisms for lateral gene transfer, such as conjugation, transformation, and transduction, whereby genetic material is exchanged between organisms.
Biological processes involving lateral gene transfer sometimes are likened to (Narra and Ochman 2006). The reproductive variances in bacteria and protists also may be symbolized by + and - signs (rather than being called male and female), and referred to as "mating strains" or "reproductive types" or similar appellations.
Many and reproduce asexually as well, and asexual reproduction has been cited in some animals, including bdelloid , which only are known to reproduce asexually, and various animals that exhibit under certain conditions. In parthenogenesis, such as found in some and , an is produced without fertilization by a male.
Generally, parthenogenesis is considered a form of asexual reproduction because it does not involve fusion of gametes of opposite sexes, nor any exchange of genetic material from two different sources (Mayr 2001) however, some authorities (McGraw-Hill 2004) classify parthenogenesis as sexual reproduction on the basis that it involves gametes or does not produce an offspring genetically identical to the parent (such as a female domestic turkey producing male offspring).
A wide spectrum of mechanisms may be exhibited. For example, many plants alternate between sexual and asexual reproduction (see Alternation of generations), and the freshwater crustacean reproduces by parthenogenesis in the spring to rapidly populate ponds, then switches to as the intensity of competition and predation increases. Many protists and fungi alternate between sexual and asexual reproduction.
A lack of is relatively rare among multicellular organisms, which exhibit the characteristics of being male or female. Biological explanations for this phenomenon are not completely settled. Current hypotheses suggest that, while asexual reproduction may have short term benefits when rapid population growth is important or in stable environments, sexual reproduction offers a net advantage by allowing more rapid generation of genetic diversity, allowing adaptation to changing environments.
Contents • • • • • • • • • • • • • Costs and benefits In asexual reproduction, an individual can reproduce without involvement with another individual, there is no fusion of , and the new organism produced inherits all of its chromosomes from one parent and thus is a genetically-similar or identical copy of the parent. Because asexual reproduction does not require the formation of gametes (often in separate individuals) and bringing them together for fertilization, nor involvement of another organism, it occurs much faster than sexual reproduction and requires less energy.
Asexual lineages can increase their numbers rapidly because all members can reproduce viable offspring. In sexual populations with two genders, some of the individuals are male and cannot themselves produce offspring. This means that an asexual lineage will have roughly double the rate of population growth under ideal conditions when compared with a sexual population half composed of males.
This is known as the two-fold cost of sex. Other advantages include the ability to reproduce without a partner in situations where the population density is low (such as for some desert lizards), reducing the chance of finding a mate, or during colonization of isolated habitats such as oceanic islands, where a single (female) member of the species is enough to start a population.
There does not need to be energy spent in finding and courting a partner for reproduction. A consequence of asexual reproduction, which may have both benefits and costs, is that offspring are typically genetically similar to their parent, with as broad a range as that individual receives from one parent.
The lack of results in fewer genetic alternatives than with sexual reproduction. Many forms of asexual reproduction, for example budding or fragmentation, produce an exact replica of the parent. This genetic similarity may be beneficial if the genotype is well-suited to a stable environment, but disadvantageous if the environment is changing. For example, if a new predator or pathogen appears and a is particularly defenseless against it, an asexual lineage is more likely to be completely wiped out by it.
In contrast, a lineage that reproduces sexually has a higher probability of having more members survive due to the genetic recombination that produces a novel genotype in each individual. Similar arguments apply to changes in the physical environment. From an standpoint, one could thus argue that asexual reproduction is inferior because it stifles the potential for change. However, there is also a significantly reduced chance of or other complications that can result from the mixing of genes. Conversely, Heng (2007) proposes that the resolution to the "paradox of sex" is that sexual reproduction actually reduces the drastic genetic diversity at the or level, resulting in the preservation of species identity, rather than the provision of evolutionary diversity for future environmental challenges.
He maintains that while genetic recombination contributes to genetic diversity, it does so secondarily and within the framework of the chromosomally defined genome. That is, the asexual process generates more diverse genomes because of the less controlled reproduction systems, while sexual reproduction generates more stable genomes.
A 2004 article in the journal Nature reported that the modern arbuscular mycorrhizas fungi, which reproduces asexually, is identical to records dating back to the Ordovician period, 460 million years ago (Pawlowska and Taylor 2004). Types of asexual reproduction Binary fission Binary fission involves the reproduction of a living by division into two parts, which each have the potential to grow to the size of the original cell.
Many single-celled organisms (unicellular), such as , , and , reproduce asexually through binary fission. Exceptions are unicellular fungi such as fission yeast, unicellular algae such as Chlamydomonas, and ciliates and some other protists, which reproduce both sexually and asexually.
Some single-celled organisms (unicellular) rely on one or more host organisms in order to reproduce, but most literally divide into two organisms. In addition, and of cells divide by binary fission.
(See also the description under .) Budding Some cells split via budding (for example baker's yeast), resulting in a "mother" and "daughter" cell. Budding is the formation of a new organism by the protrusion of part of another organism, with the protrusion normally staying attached to the primary organism for a while, before becoming free.
The new organism is naturally genetically identical to the primary one (a clone) and initially is smaller than the parent. Budding is also known on a multicellular level; an animal example is the hydra, which reproduces by budding. The buds grow into fully matured individuals, which eventually break away from the parent organism.
Vegetative reproduction Vegetative reproduction is a type of asexual reproduction found in plants where new independent individuals are formed without the production of seeds or spores. Examples for vegetative reproduction include the formation of plantlets on specialized leaves (for example in kalanchoe), the growth of new plants out of rhizomes or stolons (for example in ), or the formation of new bulbs (for example in ). The resulting plants form a clonal colony.
Spore formation Many multicellular organisms form during their in a process called sporogenesis. Exceptions are animals and some , which undergo gametic meiosis immediately followed by fertilization. Plants and many algae on the other hand undergo sporic meiosis, where meiosis leads to the formation of haploid spores rather than gametes.
These spores grow into multicellular individuals (called gametophytes in the case of plants) without a fertilization event. These haploid individuals give rise to through . Meiosis and gamete formation therefore occur in separate generations or "phases" of the life cycle, referred to as alternation of generations.
Since sexual reproduction is often more narrowly defined as the fusion of gametes (fertilization), spore formation in plant sporophytes and might be considered a form of asexual reproduction (agamogenesis) despite being the result of and undergoing a reduction in ploidy.
However, both events (spore formation and fertilization) are necessary to complete sexual reproduction in the plant life cycle. Fungi and some algae can also utilize true asexual formation, which involves giving rise to reproductive cells called mitospores that develop into a new organism after dispersal. This method of reproduction is found, for example, in conidial fungi and the red alga Polysiphonia, and involves sporogenesis without meiosis. Thus, the number of the spore cell is the same as that of the parent producing the spores.
However, mitotic sporogenesis is an exception and most spores, such as those of plants, most , and many algae, are produced by . Fragmentation Fragmentation is a form of asexual reproduction where a new organism grows from a fragment of the parent.
Each fragment develops into a mature, fully grown individual. Fragmentation is seen in many organisms, such as animals (some worms and ), , and . Some plants have specialized structures for reproduction via fragmentation, such as gemmae in . Most , which are a union of a fungus and algae or bacteria, reproduce through fragmentation to ensure that new individuals contain both symbionts. These fragments can take the form of soredia, dust-like particles consisting of fungal hyphae wrapped around photobiont cells.
Parthenogenesis Main article: Parthenogenesis is a form of agamogenesis in which an unfertilized egg develops into a new individual. Parthenogenesis occurs naturally in many plants, (e.g. water fleas, aphids, stick insects, some ants, bees and parasitic wasps), and (e.g.
some reptiles, amphibians, fish, very rarely birds). In plants, apomixis may or may not involve parthenogenesis. Parthenogenesis is one example of agamogenesis, the term for any form of reproduction that does not involve a male gamete. An example is apomixis. Apomixis and nucellar embryony Apomixis in plants is the formation of a new sporophyte without fertilization. It is important in and in , but is very rare in other seed plants.
In flowering plants, the term "apomixis" is now most often used for agamospermy, the formation of seeds without fertilization, but was once used to include vegetative reproduction. An example of an apomictic plant would be the triploid European . Apomixis mainly occurs in two forms. In gametophytic apomixis, the arises from an unfertilized egg within a diploid embryo sac that was formed without completing meiosis. In nucellar embryony, the embryo is formed from the diploid nucellus tissue surrounding the embryo sac.
Nucellar embryony occurs in some seeds. Male apomixis can occur in rare cases, such as the Saharan cypress where the genetic material of the embryo are derived entirely from . The term "apomixis" is also used for asexual reproduction in some animals, notably water-fleas, . Alternation between sexual and asexual reproduction Some species alternate between the sexual and asexual strategies, an ability known as heterogamy, depending on conditions. For example, the freshwater crustacean reproduces by parthenogenesis in the spring to rapidly populate ponds, then switches to as the intensity of competition and predation increases.
Many protists and fungi alternate between sexual and asexual reproduction. For example, the slime mold Dictyostelium undergoes binary fission as single-celled amoebae under favorable conditions.
However, when conditions turn unfavorable, the cells aggregate and switch to sexual reproduction leading to the formation of spores. The hyphae of the common mold (Rhizopus) are capable of producing both mitotic as well as meiotic spores.
Many algae similarly switch between sexual and asexual reproduction. Asexual reproduction is far less complicated than sexual reproduction. In sexual reproduction one must find a mate. Examples in animals A number of and some less advanced are known to alternate between sexual and asexual reproduction, or be exclusively asexual. Alternation is observed in a few types of , such as (which will, under favorable conditions, produce eggs that have not gone through meiosis, essentially cloning themselves) and the cape bee Apis mellifera capensis (which can reproduce asexually through a process called thelytoky).
A few species of and have the same ability (see for concrete examples). A very unusual case among more advanced vertebrates is the female turkey's ability to produce fertile eggs in the absence of a male.
The eggs result in often sickly, and nearly always male turkeys. This behavior can interfere with the incubation of eggs in turkey farming (Savage 2008). There are examples of parthenogenesis in the hammerhead shark (Eilperin 2007) and the blacktip shark (Chapman et al. 2008). In both cases, the sharks had reached sexual maturity in captivity in the absence of males, and in both cases the offspring were shown to be genetically identical to the mothers. Bdelloid rotifers reproduce exclusively asexually, and all individuals in the class Bdelloidea are females.
Asexuality arose in these animals millions of years ago and has persisted since. There is evidence to suggest that asexual reproduction has allowed the animals to develop new proteins through the Meselson effect that have allowed them to survive better in periods of dehydration (Pouchkina-Stantcheva et al. 2007). References • Chapman, D. D., B. Firchau, and M. S. Shivji. 2008. . Journal of Fish Biology 73(6): 1473. See report in Science Daily: .
Retrieved January 15, 2009. • Eilperin, J. 2007. . Washington Post May 23, 2007, p. A02. Retrieved January 16, 2008. • Graham, L., J. Graham, and L. Wilcox. 2003. Plant Biology. Upper Saddle River, NJ: Pearson Education. . • Heng, H. H. 2007. . Genome 50: 517-524. • Mayr, E. 2001. What Evolution Is. New York: Basic Books.
. • McGraw-Hill (Publisher). 2004. McGraw-Hill Concise Encyclopedia of Science and Technology, 5th Edition. McGraw Hill Professionals. . • Narra, H. P., and H. Ochman. 2006. Current Biology 16: R705–710. . • Pawlowska, T., and J. Taylor. 2004. Organization of genetic variation in individuals of arbuscular mycorrhizal fungi. Nature 427(6976): 733-737.
• Pouchkina-Stantcheva, N. N., B. M. McGee, C. Boschetti, et al. 2007. Functional divergence of former alleles in an ancient asexual invertebrate. Science 318: 268-271. Retrieved January 15, 2009. • Raven, P. H., R. F. Evert, and S. E. Eichhorn. 2005. Biology of Plants, 7th edition. New York: W.H. Freeman and Company. . • Savage, T.
F. 2008. . Oregon State Universtiy. Retrieved January 16, 2009. Credits New World Encyclopedia writers and editors rewrote and completed the Wikipedia article in accordance with New World Encyclopedia . This article abides by terms of the (CC-by-sa), which may be used and disseminated with proper attribution.
Credit is due under the terms of this license that can reference both the New World Encyclopedia contributors and the selfless volunteer contributors of the Wikimedia Foundation.
To cite this article for a list of acceptable citing formats.The history of earlier contributions by wikipedians is accessible to researchers here: • The history of this article since it was imported to New World Encyclopedia: • Note: Some restrictions may apply to use of individual images which are separately licensed.
best asexual dating non asexual reproduction - How to Understand Asexual People: 8 Steps (with Pictures)
Sexual And Asexual Reproduction In Plants And Animals Organisms, which include humans, animals, and plants reproduce as a law of nature, a means of ensuring the survival of the species and in the context of evolution.
There are two major classifications of reproduction, sexual and asexual reproductions. Each has its own advantages and disadvantages and each is appropriate for different species. Vertebrates, such as humans, are almost exclusively sexual in their reproduction. Many simpler animals are asexual. It is important to understand how these processes differ. Asexual reproduction Asexual reproduction spans a variety of methods.
The simplest single-celled or unicellular organisms including archaea, amoeba, bacteria, reproduce by In the process, the cells simply divide in half creating a clone of the parent and hold the benefit of usually being very quick and energy efficient. For example, bacteria that reproduce by binary fission can give rise to progeny every few hours. Multiple fission also exists in which they split into more than one offspring.
Organisms such as Cryptosporidium parvum, sporozoan, etc may utilize multiple fission. While in multicellular organisms, a similar method is named fragmentation in which small pieces break off and grow into new organisms. Another method involves budding, which produces a completely new adult by remaining attached to the original body or develops from the original body. A common thread in all this is that the offspring is a direct clone of the parent. The purpose of reproduction as we’re well aware is to propagate one’s own genes.
Evolutionarily, asexual reproduction is a good bet for the species. It is quick, simple and the genes of the parent will not be diluted by those of another individual.
Also, an organism that reproduces asexually can reproduce about twice as fast as one that reproduces sexually. Sexual reproduction Sexual reproduction is the combination of reproductive cells from two individuals to form a third unique offspring.
Sexual reproduction produces offspring with a different combination of . align=”justify”One must understand that the sexual reproduction is a lot more complex than asexual reproduction. It includes the production of gametes, which have half the number of chromosomes of all other cells in the organism and the process of meiosis, which produceshaploid cells from diploid cells which could lead to the possibility of two copies of a single chromosome crossing over to create a completely new chromosome that contains a new combination of genes.
You see, switching from chromosome to chromosome is a good way to ensure that the genes will keep active in a given population. Besides these, factors like gestation period also play an important role in sexual reproduction. Gestation period is the timeframe it requires for the fetus to fully develop either internally (like the mother’s womb) or externally (like an egg). Difference between the sexual and asexual reproduction.
Let us check out some significant difference between the sexual and Asexual reproduction. Asexual Reproduction Sexual Reproduction Occurs in lower invertebrates, lower chordates, and prokaryotic microorganisms and in some eukaryotic single-celled and multi-celled organisms.
Occurs almost in all types of multicellular organisms including humans, animals and mostly in higher plants. It is uniparental. It is usually bi-parental. Gametes are not formed. Gametes are formed. Somatic cells of parents are involved. Germ cells of parents are involved. No fertilization occurs. Fertilization takes place. The absence of reproductive organs. Presence of fully developed reproductive organs. Only mitosis type of cell division occurs. Both meiosis and mitosis type of cell division occurs.
Original parent disappears after the process of reproduction. Original parents remain alive after the process of reproduction. The progeny and the parent will be genetically identical. The progenies will be genetically different from the parents. Characteristics of only one parent are inherited. Characteristics of both parents are inherited. The genes and genetic material are just multiplied and passed on to new organisms from the parent. The genetic material undergoes intermixing from both parents to form a new set of genetic material.
Multiplication is very rapid and in lesser time. Multiplication is not so rapid and takes the longest time to complete. The number of offspring produced may vary from two to many.
The number of offspring produced are comparatively lower. No evolutionary significance. Has evolutionary significance in the population. Bacterial fission, fragmentation, spore formation, budding of hydra are different types of asexual reproduction.
Syngamy, external fertilization and conjugation are different types of sexual reproduction. Facts about Reproduction • The record for the longest ever gestation period is held by the elephant which has around 640-660 days as compared to a human’s 280 days.
• The deepsea male anglerfish bites on to the much larger females and then, the tissues starts to fuse until the male fish looks like just a lump of tissue dangling from the female’s body. The male anglerfish receives nutrients and the female fish has access to male sperms to fertilize its eggs.
• Oysters are protandric creatures, this means that they can change from male to female over the course of their lifetime. • Abiogenesis is a process that still remains a mystery. It speculates how the first ever life arose from nonliving matter such as carbon (Organic compounds.) To know more about sexual and asexual reproduction, visit BYJU’S.
While asexual reproduction only involves one organism, sexual reproduction requires both a male and a female. Some plants and unicellular organisms reproduce asexually. Most mammals and fish use sexual reproduction.
Some organisms like corals and komodo dragons can reproduce either sexually or asexually. But in the long term (over several generations), lack of sexual reproduction compromises their ability to adapt to the environment because they do not benefit from the genetic variation introduced by sexual reproduction.
Comparison chart Asexual Reproduction versus Sexual Reproduction comparison chart Asexual Reproduction Sexual Reproduction Number of organisms involved One parent needed Two parents are required to mate Cell division Cells divide by Fission, budding , or regeneration Cells divide by Meiosis Types Budding, vegetative reproduction, fragmentation, spore formation Syngamy and conjugation Advantages Time Efficient; no need to search for mate, requires less energy Variation, Unique., organism is more protected Disadvantages No variation - if the parent has a genetic disease, offspring does too.
Requires two organisms, requires more energy Evolution There is very little chance of variation with asexual reproduction. Mutations in can still occur but not nearly as frequently as in sexual reproduction. Sexual reproduction leads to genetic variation in new generations of offspring. This is fundamental to evolution. Involvement of sex cells No formation or fusion of gametes (sex cell) Formation and fusion of gametes (sex cell) occurs Found in Lower organisms Higher invertebrates and all vertebrates Unit of reproduction May be whole parent body or a bud or a fragment or a single somatic cell Gamete Time taken Asexual reproduction is completed in a very short period of time.
Sexual reproduction can take several months to complete. Number of offspring Two or more One or more Types There are several different types of asexual reproduction. These include budding, where the offspring grows out of the body of the parent, and gemmules, where the parent releases a specialized of cells that will become a new individual. There are two types of sexual reproduction. Syngamy is the permanent fusion of two haploid gametes to create a zygote.
In humans, this is called fertilization. Conjugation, on the other hand, is temporary fusion using a cytoplasmic bridge. This is particularly seen in bacteria, which pass across the bridge. Process Asexual reproduction is reproduction that occurs without any interaction between two different members of a species. Cells divide using , in which each chromosome is copied before the nucleus divides, with each new cell receiving identical genetic information.
Cell division in asexual and sexual reproduction Sexual reproduction is reproduction that requires a male and a female of the same species to contribute genetic material. Special cells called gametes are produced through , which halves the number of chromosomes in each resulting cell. These cells are called haploid gametes.
Fertilization occurs when two gametes – one from a male and one from a female – combine, producing a zygote with its own individual genetic makeup. Examples Asexual reproduction is used by many plants, e.g.
spider plants, bacteria, hydra, , and jellyfish. It is also involved in the creation of , when one zygote splits into two identical copies. Sexual reproduction is used by most mammals, fish, , birds and insects. Advantages and Disadvantages Asexual reproduction is well suited for organisms that remain in one place and are unable to look for mates, in environments that are stable.
It is usually used by simple organisms such as . However, asexual reproduction does not lead to variation between organisms, meaning that entire groups can be wiped out by disease, or if the stable environment changes. Sexual reproduction allows for variation, the most fundamental element of . It therefore creates species that can adapt to new environments and that cannot be wiped out by a single disease.
However, sexual reproduction requires significant on the part of the organism to find a mate. It is not well suited to organisms that are isolated or stuck in place. References • • Anonymous comments (5) October 12, 2013, 8:53am thanks , useful — 136.✗.✗.48 ▲ 36 ▼ December 9, 2013, 2:04pm Used this in school!
Thanx — 66.✗.✗.162 ▲ 11 ▼ March 9, 2014, 4:16pm thanks this site! you save my life for my teachers homework! — 107.✗.✗.44 ▲ 8 ▼ May 14, 2013, 7:45am thanks it's really helpful — 175.✗.✗.11 ▲ 0 ▼ January 31, 2014, 3:42pm Its a nice — 1.✗.✗.33 ▲ -56 ▼
How (some) Asexuals ...Have Sex 👍🏻 [CC]