kolanuraven
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Good job of plucking different sentences from different posts and putting them all together into one.
Red Robin I saw where no one answered your question.What is asexual reproduction?
Asexual reproduction (also known as agamogenesis) is the simplest form of reproduction and does not involve meiosis, gamete formation, or fertilization. In laymen's terms, there is only one "parent" involved. This form of reproduction is common among simple organisms such as amoeba and other single-celled organisms, although most plants produce asexually as well (see vegetative reproduction).
Because it does not require male and female participation, asexual reproduction occurs faster than sexual reproduction and requires less energy. Additionally, asexual reproduction produces an exact replica of the parent due to the lack of genetic recombination. From an evolutionary 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 mutation or other complications that can result from the mixing of genes.
Many, but not all, single-celled organisms produce asexually through binary fission. Some single-celled organisms rely on one or more host organisms in order to reproduce, but most literally divide into two organisms. An exception to the rule are ciliates, which reproduce both sexually and asexually. All prokaryotes (the vast majority of which are unicellular) reproduce asexually.
There are three types of asexual reproduction utilized by plants: regeneration, vegetative reproduction, and spore formation. The last type, spore formation, involves the production of reproductive cells called spores that contain DNA and develop into a new organism after dispersal. This method of reproduction is found in the ferns, and involves sporogenesis without meiosis. Thus the chromosome number of the spore cell is the same as that of the parent produciung the spores.
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Advantages and disadvantages
Not only does asexual reproduction offer a variety of ways to reproduce it also offers a number of advantages. For instance, asexual reproduction does not require participation of both a male and a female, while sexual reproduction does. This is why asexual reproduction is faster and requires less energy than sexual reproduction because organisms that can reproduce asexually do not have to spend time trying to find a mate. Instead, they can spend their time reproducing.
Since asexual reproduction is faster than sexual reproduction it gives plants the ability to increase the numbers of a plant population more quickly. Since asexual reproduction only requires one parent it only takes one plant to decide to create a large colony of plants, hence, the proliferation of dandelions and other weeds such as the dandelion. This helps to introduce plants to new habitats.
Another advantage is that asexual reproduction produces an exact replica of the parent. Every time asexual reproduction occurs plants end up with the same set of genes over and over again. Since their gene sequence is not changed their chances of survival are, therefore better because if the parent lived in the same environment and were able to adapt to it, they too should be able to survive (Plant Biology, 2003).
This, however, can serve as a disadvantage. If new factors in the environment are introduced that do not favor the species in question, none of the individual members possess adaptive traits (which they then would've passed on to offspring). Thus, it will be harder for the species as a whole to survive.
It is still very difficult for an asexual worm to find a date to copulate with??? Is it not?
Amorous worms reveal effects of Chernobyl
WORMS contaminated by radioactivity from the Chernobyl nuclear accident have started having sex with each other instead of on their own. According to Ukrainian scientists, they may have changed their sexual behaviour to increase their chances of survival. It's one of the first pieces of direct evidence on how wildlife is affected by radioactive pollution.
Although there is a wealth of evidence on the impact of ionising radiation on humans, its effects on wildlife are poorly understood. In the past the International Commission on Radiological Protection, which recommends radiation safety limits, has set no limits to protect wildlife, assuming that as long as humans were protected, animals and plants would be too.
But in recent years the ICRP has abandoned this assumption and launched an investigation into how best to safeguard "non-human species". Many researchers are focusing on how wildlife has been affected by the radioactivity that spewed from the exploded reactor at Chernobyl in Ukraine, 17 years ago this month.
Gennady Polikarpov and Victoria Tsytsugina from the Institute of Biology of the Southern Seas in Sevastopol studied the reproduction of certain sedimentary worms that are vital to aquatic ecosystems (Journal of Environmental Radioactivity, vol 66, p 141). They compared the behaviour of three species in a lake near Chernobyl with the same species in a lake 20 kilometres away. The lakes had similar temperatures and chemical composition, but the worms in the Chernobyl lake had received 20 times as much radiation as those in the other lake. The researchers found some remarkable changes in the worms' sexual habits.
Two species had switched from asexual to sexual reproduction, as they are capable of doing. The proportion of Nais pardalis seeking partners for sex was 5 per cent in the normal lake but 22 per cent in the Chernobyl lake, while the proportions of Nais pseudobtusa doing the same were 10 per cent and 23 per cent respectively. However, the third species, Dero obtusa, showed double the rate of asexual reproduction in the polluted lake.
Polikarpov thinks the worms have switched to sexual reproduction in an attempt to protect themselves from the radiation. Sexual reproduction allows natural selection to promote genes that offer better protection from radiation damage, and "the resistance of populations as a whole will be increased", he suggests. Carmel Mothersill from the Dublin Institute of Technology, one of the experts helping the ICRP develop its new policy on protecting wildlife, agrees. "It is a plausible mechanism," she says.
Today, he travels the U.S. giving some 40 lectures per year on the subject "Does God Exist?". He is a teacher and geologist by profession. He holds a B.S. degree from Indiana. University in Education with a concentration in Physics and mathematics. He holds a M.S. degree from Indiana University in Education with a concentration in Chemistry and Psychometry. He also holds a M.S. degree from Notre Dame University in Geology and Earth Science. His most recent honors include: Distinguished Physics Teacher for the State of Indiana - 1985 by the American Association of Physics Teachers. S.T.A.R Instructor for Indiana Department of Public Instruction - 1990. "South Bend Community School Corporation High School Teacher of the Year" and "School Corporation Teacher of the Year" - 1991.
http://www.doesgodexist.org/Phamplets/GodsRevelationInHisRocksAndInHisWord/GodsRevelationInHisRocksAndInHisWord.htmlGenesis makes perfect sense when it is followed in a literal and careful way,(following the hebrew text), recognizing that the sequence given was used initially and still takes place today in processes like succession.
Oldtimer said:mp.freelance said:theHiredMansWife said:I haven't voted as you don't have my choice available...
The two do not have to be mutually exclusive. I think they're both right...
(that of evolution and God, that is, since Darwinism isn't quite the same thing as evolution)
I completely agree. Why would God be less powerful if he created the Universe in billions of years instead of just five thousand? It's just our perception of time anyway. The Pope said that there's room in Christianity for evolution, and even as a semi-apostate Catholic I agree.
Thats kind of the stance I've taken...What is a day to God? You can't just throw out the entire evolution theory because some parts are unproven- because you can see some instances taking place daily... How did horned herefords become polled?
mp.freelance said:The Pope said that there's room in Christianity for evolution,
zephyrus31 said:We're not monkeys.