Sabado, Marso 3, 2012

project in biology

I; INTRODUCTION:
                                                           ''MUTATION"

In molecular biology and genetics, mutations are changes in a genomic sequence: the DNA sequence of a cell's genome or the DNA or RNA sequence of a virus. They can be defined as sudden and spontaneous changes in the cell. Mutations are caused by radiation, viruses, transposons and mutagenic chemicals, as well as errors that occur during meiosis or DNA replication. They can also be induced by the organism itself, by cellular processes such as hypermutation. Mutation can result in several different types of change in sequences; these can either have no effect, alter the product of a gene, or prevent the gene from functioning properly or completely. Studies in the fly Drosophila melanogaster suggest that if a mutation changes a protein produced by a gene, this will probably be harmful, with about 70 percent of these mutations having damaging effects, and the remainder being either neutral or weakly beneficial. Due to the damaging effects that mutations can have on genes, organisms have mechanisms such as DNA repair to prevent mutations. " The causes of mutations" Mutations happen for several reasons. DNA fails to copy accurately Most of the mutations that we think matter to evolution are "naturally-occurring." For example, when a cell divides, it makes a copy of its DNA — and sometimes the copy is not quite perfect. That small difference from the original DNA sequence is a mutation.
External influences can create mutations Mutations can also be caused by exposure to specific chemicals or radiation. These agents cause the DNA to break down. This is not necessarily unnatural — even in the most isolated and pristine environments, DNA breaks down. Nevertheless, when the cell repairs the DNA, it might not do a perfect job of the repair. So the cell would end up with DNA slightly different than the original DNA and hence, a mutation.
              there are 8 different kinds of syndrome            






                              progeria syndrome 
Progeria (also known as "Hutchinson–Gilford Progeria Syndrome", "Hutchinson–Gilford syndrome" and "Progeria syndrome" is an extremely rare genetic condition wherein symptoms resembling aspects of aging are manifested at an early age. The word progeria comes from the Greek words "pro" (πρό), meaning "before", and "géras" (γῆρας), meaning "old age". The disorder has very low incidences and occurs in an estimated 1 per 8 million live births. Those born with progeria typically live to their mid teens and early twenties.It is a genetic condition that occurs as a new mutation (de novo), and is rarely inherited. Although the term progeria applies strictly speaking to all diseases characterized by premature aging symptoms, and is often used as such, it is often applied specifically in reference to Hutchinson-Gilford Progeria Syndrome (HGPS). Scientists are particularly interested in progeria because it might reveal clues about the normal process of aging. Progeria was first described in 1886 by Jonathan Hutchinson.It was also described independently in 1897 by Hastings Gilford. The condition was later named Hutchinson-Gilford Progeria Syndrome (HGPS). cri-do-chat syndrome:
Cri du chat syndrome, also known as chromosome 5p deletion syndrome, 5p minus syndrome or Lejeune’s syndrome, is a rare genetic disorder due to a missing part of chromosome 5. Its name is a French term (cat-cry or call of the cat) referring to the characteristic cat-like cry of affected children. It was first described by Jérôme Lejeune in 1963.[1] The condition affects an estimated 1 in 50,000 live births, strikes all ethnicities, and is more common in females by a 4:3 ratio turner syndrome:
cTurner syndrome or Ullrih-Turner syndrome (also known as "Gonadal dysgenesis":550), 45 XO, encompasses several conditions in human females, of which monosomy X (absence of an entire sex chromosome, the Barr body) is most common. It is a chromosomal abnormality in which all or part of one of the sex chromosomes is absent (unaffected humans have 46 chromosomes, of which two are sex chromosomes). Normal females have two X chromosomes, but in Turner syndrome, one of those sex chromosomes is missing or has other abnormalities. In some cases, the chromosome is missing in some cells but not others, a condition referred to as mosaicism or 'Turner mosaicism'. Occurring in 1 in 2000 – 1 in 5000 phenotypic females, the syndrome manifests itself in a number of ways. There are characteristic physical abnormalities, such as short stature, swelling, broad chest, low hairline, low-set ears, and webbed necks. Girls with Turner syndrome typically experience gonadal dysfunction (non-working ovaries), which results in amenorrhea (absence of menstrual cycle) and sterility. Concurrent health concerns are also frequently present, including congenital heart disease, hypothyroidism (reduced hormone secretion by the thyroid), diabetes, vision problems, hearing concerns, and many autoimmune diseases. Finally, a specific pattern of cognitive deficits is often observed, with particular difficulties in visuospatial, mathematical, and memory areas. Turner's syndrome is named after Henry H. Turner. Turner syndrome or Ullrich-Turner syndrome (also known as "Gonadal dysgenesis":550), 45 XO, encompasses several conditions in human females, of which monosomy X (absence of an entire sex chromosome, the Barr body) is most common. It is a chromosomal abnormality in which all or part of one of the sex chromosomes is absent (unaffected humans have 46 chromosomes, of which two are sex chromosomes). Normal females have two X chromosomes, but in Turner syndrome, one of those sex chromosomes is missing or has other abnormalities. In some cases, the chromosome is missing in some cells but not others, a condition referred to as mosaicismor 'Turner mosaicism'. Occurring in 1 in 2000 – 1 in 5000 phenotypic females, the syndrome manifests itself in a number of ways. There are characteristic physical abnormalities, such as short stature, swelling, broad chest, low hairline, low-set ears, and webbed necks. Girls with Turner syndrome typically experience gonadal dysfunction (non-working ovaries), which results in amenorrhea (absence of menstrual cycle) and sterility. Concurrent health concerns are also frequently present, including congenital heart disease, hypothyroidism (reduced hormone secretion by the thyroid), diabetes, vision problems, hearing concerns, and many autoimmune diseases. Finally, a specific pattern of cognitive deficits is often observed, with particular difficulties in visuospatial, mathematical, and memory areas. Turner's syndrome is named after Henry H. Turner. klinefelter syndrome:
Klinefelter syndrome, 47, XXY, or XXY syndrome is a condition in which human males have an extra X chromosome. While females have an XX chromosomal makeup, and males an XY, affected individuals have at least two X chromosomes and at least one Y chromosome. Because of the extra chromosome, individuals with the condition are usually referred to as "XXY Males", or "47, XXY Males".Klinefelter's syndrome is the symptoms of the disease Seminiferous Tubule Dysgenesis As stated below this form of hypogonadism was first described by Klinefelter et al in 1942. The account given by Klinefelter came to be known as Klinefelter's syndrome as his name appeared first on the published paper, and Seminiferous Tubule Dysgenesis was no longer used. Babies born with XXY or any other karyotype including at least 1 additional X do not have Klinefelter's syndrome, as the syndrome itself only manifests after the onset of puberty, if it manifests at all. Williams Textbook of Endocrinology 8th Edition page 879 "Seminiferous tubule dysgenesis is a common cause of primary hypogonadism and male infertility. This syndrome was first defined as a clinical entity by Klinefelter and associates. The characteristic features, which first become manifest during adolescence, are gynaecomastia, a variable degree of eunuchoidism, [atrophic testes] with hyalinization of the seminiferous tubules, aggregation of the [cells], aspermatogenesis, and increased excretion of urinary gonadotropin....." In humans, 47XXY is the most common sex chromosome aneuploidy in malesand the second most common condition caused by the presence of extra chromosomes. The chromosome constitution (karyotype) exists in roughly between 1:500 to 1:1000 live male births but many of these people may not show symptoms. Other mammals also have the XXY syndrome, including mice. Principal effects include hypogonadism and reduced fertility. A variety of other physical and behavioural differences and problems are common, though severity varies and many XXY boys have few detectable symptoms. Not all XXY men develop Klinefelter's syndrome. The syndrome was named after Dr. Harry Klinefelter, who in 1942 worked with Fuller Albright at Massachusetts General Hospital in Boston, Massachusetts and first described it in the same year. Klinefelter syndrome, 47, XXY, or XXY syndrome is a condition in which human males have an extra X chromosome. While females have an XX chromosomal makeup, and males an XY, affected individuals have at least two X chromosomes and at least one Y chromosome. Because of the extra chromosome, individuals with the condition are usually referred to as "XXY Males", or "47, XXY Males". Klinefelter's syndrome is the symptoms of the disease Seminiferous Tubule Dysgenesis As stated below this form of hypogonadism was first described by Klinefelter et al in 1942. The account given by Klinefelter came to be known as Klinefelter's syndrome as his name appeared first on the published paper, and Seminiferous Tubule Dysgenesis was no longer used. Babies born with XXY or any other karyotype including at least 1 additional X do not have Klinefelter's syndrome, as the syndrome itself only manifests after the onset of puberty, if it manifests at all. Williams Textbook of Endocrinology 8th Edition page 879 "Seminiferous tubule dysgenesis is a common cause of primary hypogonadism and male infertility. This syndrome was first defined as a clinical entity by Klinefelter and associates. The characteristic features, which first become manifest during adolescence, are gynaecomastia, a variable degree of eunuchoidism, [atrophic testes] with hyalinization of the seminiferous tubules, aggregation of the [cells], aspermatogenesis, and increased excretion of urinary gonadotropin....." In humans, 47XXY is the most common sex chromosome aneuploidy in males and the second most common condition caused by the presence of extra chromosomes. The chromosome constitution (karyotype) exists in roughly between 1:500 to 1:1000 live male births but many of these people may not show symptoms. Other mammals also have the XXY syndrome, including mice. Principal effects include hypogonadism and reduced fertility. A variety of other physical and behavioural differences and problems are common, though severity varies and many XXY boys have few detectable symptoms. Not all XXY men develop Klinefelter's syndrome. The syndrome was named after Dr. Harry Klinefelter, who in 1942 worked with Fuller Albright at Massachusetts General Hospital in Boston, Massachusetts and first described it in the same year. down syndrome:
Down syndrome or Down's syndrome, (also known as trisomy 21), is a chromosomal condition caused by the presence of all or part of an extra 21st chromosome. It is named after John Langdon Down, the British physician who described the syndrome in 1866. The condition was clinically described earlier in the 19th century by Jean Etienne Dominique Esquirol in 1838 and Edouard Seguin in 1844. Down syndrome was identified as a chromosome 21 trisomy by Dr. Jérôme Lejeune in 1959. Down syndrome in a fetus can be identified through chorionic villus sampling or amniocentesis during pregnancy, or in a baby at birth. Down syndrome is a chromosomal condition characterized by the presence of an extra copy of genetic material on the 21st chromosome, either in whole (trisomy 21) or part (such as due to translocations). The effects and extent of the extra copy vary greatly among people, depending on genetic history, and pure chance. The incidence of Down syndrome is estimated at 1 per 733 births, although it is statistically more common with older parents due to increased mutagenic exposures upon some older parents' reproductive cells. Other factors may also play a role. Down syndrome occurs in all human populations, and analogous conditions have been found in other species such as chimpanzees and mice. Often Down syndrome is associated with some impairment of cognitive ability and physical growth, and a particular set of facial characteristics. Individuals with Down syndrome usually have low intelligence, such as to constitute mild to moderate intellectual disability. Many children with Down syndrome who have received family support, enrichment therapies and tutoring manage to graduate from high school and college, and are able to do paid work. The average IQ of children with Down syndrome is around 50, compared to normal children with an IQ of 100. A small number have a severe to high degree of intellectual disability. Individuals with Down syndrome may have some or all of the following physical characteristics: microgenia (an abnormally small chin), an unusually round face, macroglossia (protruding or oversized tongue), an almond shape to the eyes caused by an epicanthic fold of the eyelid, upslanting palpebral fissures (the separation between the upper and lower eyelids), shorter limbs, a single transverse palmar crease (a single instead of a double crease across one or both palms), poor muscle tone, and a larger than normal space between the big and second toes. Health concerns for individuals with Down syndrome include a higher risk for congenital heart defects, gastroesophageal reflux disease, recurrent ear infections that may lead to hearing loss, obstructive sleep apnea, thyroid dysfunctions, and obesity. Early childhood intervention, screening for common problems, medical treatment where indicated, a conducive family environment, and vocational training can improve the overall development of children with Down syndrome. Education and proper care will improve quality of life significantly, despite genetic limitations Down syndrome or Down's syndrome, (also known as trisomy 21), is a chromosomal condition caused by the presence of all or part of an extra 21st chromosome. It is named after John Langdon Down, the British physician who described the syndrome in 1866. The condition was clinically described earlier in the 19th century by Jean Etienne Dominique Esquirol in 1838 and Edouard Seguin in 1844. Down syndrome was identified as a chromosome 21 trisomy by Dr. Jérôme Lejeune in 1959. Down syndrome in a fetus can be identified through chorionic villus sampling or amniocentesis during pregnancy, or in a baby at birth. Down syndrome is a chromosomal condition characterized by the presence of an extra copy of genetic material on the 21st chromosome, either in whole (trisomy 21) or part (such as due to translocations). The effects and extent of the extra copy vary greatly among people, depending on genetic history, and pure chance. The incidence of Down syndrome is estimated at 1 per 733 births, although it is statistically more common with older parents due to increased mutagenic exposures upon some older parents' reproductive cells. Other factors may also play a role. Down syndrome occurs in all human populations, and analogous conditions have been found in other species such as chimpanzees and mice. Often Down syndrome is associated with some impairment of cognitive ability and physical growth, and a particular set of facial characteristics. Individuals with Down syndrome usually have low intelligence, such as to constitute mild to moderate intellectual disability. Many children with Down syndrome who have received family support, enrichment therapies and tutoring manage to graduate from high school and college, and are able to do paid work. The average IQ of children with Down syndrome is around 50, compared to normal children with an IQ of 100. A small number have a severe to high degree of intellectual disability. Individuals with Down syndrome may have some or all of the following physical characteristics: microgenia (an abnormally small chin),an unusually round face, macroglossia(protruding or oversized tongue), an almond shape to the eyes caused by an epicanthic fold of the eyelid, upslanting palpebral fissures (the separation between the upper and lower eyelids), shorter limbs, a single transverse palmar crease (a single instead of a double crease across one or both palms), poor muscle tone, and a larger than normal space between the big and second toes. Health concerns for individuals with Down syndrome include a higher risk for congenital heart defects, gastroesophageal reflux disease, recurrent ear infections that may lead to hearing loss, obstructive sleep apnea, thyroid dysfunctions, and obesity. Early childhood intervention, screening for common problems, medical treatment where indicated, a conducive family environment, and vocational training can improve the overall development of children with Down syndrome. Education and proper care will improve quality of life significantly, despite genetic limitations edward syndrome:
cB_I/ Edwards syndrome (also known as Trisomy 18 (T18) or Trisomy E) is a genetic disorder caused by the presence of all or part of an extra 18th chromosome. It is named after John H. Edwards, who first described the syndrome in 1960. It is the second most common autosomal trisomy, after Down syndrome, that carries to term. Edwards syndrome is caused by the presence of three – as opposed to two – copies of chromosome 18 in a fetus's or infant's cells. Edwards' syndrome occurs in around one in 6,000 live births and around 80 per cent of those affected are female. The majority of fetuses with the syndrome die before birth. The incidence increases as the mother's age increases. The syndrome has a very low rate of survival, resulting from heart abnormalities, kidney malformations, and other internal organ disorders. Edwards syndrome (also known as Trisomy 18 (T18) or Trisomy E) is a genetic disorder caused by the presence of all or part of an extra 18th chromosome. It is named after John H. Edwards, who first described the syndrome in 1960. It is the second most common autosomal trisomy, after Down syndrome, that carries to term. Edwards syndrome is caused by the presence of three – as opposed to two – copies of chromosome 18 in a fetus's or infant's cells. Edwards' syndrome occurs in around one in 6,000 live births and around 80 per cent of those affected are female. The majority of fetuses with the syndrome die before birth. The incidence increases as the mother's age increases. The syndrome has a very low rate of survival, resulting from heart abnormalities, kidney malformations, and other internal organ disorders. patau syndrome:
Patau syndrome, also known as trisomy 13 and trisomy D, is a chromosomal abnormality, a syndrome in which a patient has an additional chromosome 13 due to a nondisjunction of chromosomes during meiosis. Some are caused by Robertsonian translocations. The extra chromosome 13 disrupts the normal course of development, causing heart and kidney defects, amongst other features characteristic of Patau syndrome.[vague] Like all nondisjunction conditions (such as Down syndrome and Edwards syndrome), the risk of this syndrome in the offspring increases with maternal age at pregnancy, with about 31 years being the average. Patau syndrome affects somewhere between 1 in 10,000 and 1 in 21,700 live births. Patau syndrome, also known as trisomy 13 and trisomy D, is a chromosomal abnormality, a syndrome in which a patient has an additional chromosome 13 due to a nondisjunction of chromosomes during meiosis. Some are caused by Robertsonian translocations. The extra chromosome 13 disrupts the normal course of development, causing heart and kidney defects, amongst other features characteristic of Patau syndrome.[vague] Like all nondisjunction conditions (such as Down syndrome and Edwards syndrome), the risk of this syndrome in the offspring increases with maternal age at pregnancy, with about 31 years being the average. Patau syndrome affects somewhere between 1 in 10,000 and 1 in 21,700 live births.[2] albinism syndrome:
Albinism–deafness syndrome (also known as "Woolf syndrome," and "Ziprkowski–Margolis syndrome") is a condition characterized by congenital neural deafness and a severe or extreme piebald-like phenotype with extensive areas of hypopigmentation. A locus at Xq26.3-q27.I has been suggested. It has been suggested that it is a form of Waardenburg syndrome type II.














                                                                            :CONCLUSION:

               THERE I CONCLUDE I MUST THANK GOD FOR MAKING ME NORMAL
                AND  I REALLY THANKS THAT I AM NOT ONE OF THEM SUFFERING 
                 THAT DISEASE OR SYDROME  AND I MUST PRAY FOR ALL OF THEM 
                 THAT THEY WILL BE OKEY.,.,.,.  AND I LEARNED THAT MUTATION IS 
                 ACCIDENTALLY PROCIDURE OF DNA...,.,,.,























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