https://padlet.com/whitesharkfw/7f0rta3qa2rjbded done by : Sara ,Fayez , Farah en-us 2021-04-13 04:54:44 UTC 2024-05-30 08:16:31 UTC hello@padlet.com saraayad01 https://padlet.com/whitesharkfw/7f0rta3qa2rjbded/wish/1410426486 Point mutation, change within a gene in which one base pair in the DNA sequence is altered. Point mutations are frequently the result of mistakes made during DNA replication, although modification of DNA, such as through exposure to X-rays or to ultraviolet radiation, also can induce point mutations. 

]]> 2021-04-13 05:00:42 UTC https://padlet.com/whitesharkfw/7f0rta3qa2rjbded/wish/1410426486 whitesharkfw https://padlet.com/whitesharkfw/7f0rta3qa2rjbded/wish/1410426592 In biology, a mutation is an alteration in the nucleotide sequence of the genome of an organism, virus, or extrachromosomal DNA. Viral genomes contain either DNA or RNA.
there are two types of mutation gene mutations and chromosome mutation ]]> 2021-04-13 05:00:45 UTC https://padlet.com/whitesharkfw/7f0rta3qa2rjbded/wish/1410426592 whitesharkfw https://padlet.com/whitesharkfw/7f0rta3qa2rjbded/wish/1410431540 A gene variant is a permanent change in the DNA sequence that makes up a gene. This type of genetic change used to be known as a gene mutation, but because changes in DNA do not always cause disease, it is thought that gene variant is a more accurate term. Variants can affect one or more DNA building blocks (nucleotides) in a gene.
there are 5 types of gene mutation 
point mutation 
substitution 
insertion 
deletion 
frameshift ]]> 2021-04-13 05:03:31 UTC https://padlet.com/whitesharkfw/7f0rta3qa2rjbded/wish/1410431540 saraayad01 https://padlet.com/whitesharkfw/7f0rta3qa2rjbded/wish/1410444686 A substitution mutation occurs when one base pair is substituted for another. For example, this would occur when one nucleotide containing cytosine is accidentally substituted for one containing guanine. ]]> 2021-04-13 05:10:11 UTC https://padlet.com/whitesharkfw/7f0rta3qa2rjbded/wish/1410444686 taherfarah176 https://padlet.com/whitesharkfw/7f0rta3qa2rjbded/wish/1410447763 Description -> Insertion is a type of mutation involving the addition of genetic material. An insertion mutation can be small, involving a single extra DNA base pair, or large, involving a piece of a chromosome.
Causes -> An insertion mutation occurs when an extra nucleotide is added to the DNA strand during replication. This can happen when the replicating strand "slips," or wrinkles, which allows the extra nucleotide to be incorporated
 
 For example, the mld mutant mouse has a duplicated and partially inverted myelin basic protein gene in close proximity to the native gene. This results in a decreased level and an abnormal temporal schedule of myelin basic protein synthesis with a clinical phenotype milder than that of the allelic shiverer mutant
 
 Diagnostic technique ->
 
 Uses a capillary-based gel electrophoresis system. The method used to detect human disease gene mutations varies depending on the mutation type. Sequence analysis allows for the interrogation of all bases within a gene and is used routinely by clinical laboratories to detect point mutations and small insertions and deletions. Alternative methods, such as Southern blotting, quantitative PCR, array CGH, or multiplex ligation-dependent probe amplification (MLPA), are required to detect deletions encompassing an entire exon or more.

]]> 2021-04-13 05:11:45 UTC https://padlet.com/whitesharkfw/7f0rta3qa2rjbded/wish/1410447763 taherfarah176 https://padlet.com/whitesharkfw/7f0rta3qa2rjbded/wish/1410451980 Description -> is a mutation (a genetic aberration) in which a part of a chromosome or a sequence of DNA is left out during DNA replication. Any number of nucleotides can be deleted, from a single base to an entire piece of chromosome.
 
 causes -> The smallest single base deletion mutations occur by a single base flipping in the template DNA, followed by template DNA strand slippage, within the DNA polymerase active site. Deletions can be caused by errors in chromosomal crossover during meiosis, which causes several serious genetic diseases.
 
 Example of disorder -> Deletions are responsible for an array of genetic disorders, including some cases of male infertility, two thirds of cases of Duchenne muscular dystrophy, and two thirds of cases of cystic fibrosis
 
 Diagnostic technique -> 
 
 Amplification refractory mutation system (ARMS) PCR: Allele-specific amplification (AS-PCR) or ARMS-PCR is a general technique for the detection of any point mutation or small deletion.]]> 2021-04-13 05:13:59 UTC https://padlet.com/whitesharkfw/7f0rta3qa2rjbded/wish/1410451980 saraayad01 https://padlet.com/whitesharkfw/7f0rta3qa2rjbded/wish/1420048373 Chromosome mutation is the process of change that results in rearranged chromosome parts, abnormal numbers of individual chromosomes, or abnormal numbers of chromosome sets.
There are four types of chromosomal mutations:
A) Deletion
B) Inversion
C) Translocation
D) Nondisjunction]]> 2021-04-15 08:20:57 UTC https://padlet.com/whitesharkfw/7f0rta3qa2rjbded/wish/1420048373 saraayad01 https://padlet.com/whitesharkfw/7f0rta3qa2rjbded/wish/1420057166 A frameshift mutation is a type of mutation involving the insertion or deletion of a nucleotide in which the number of deleted base pairs is not divisible by three. "Divisible by three" is important because the cell reads a gene in groups of three bases.
There are two types of frame shift mutations. They are insertions and deletions. Insertions involve the insertion of one of more extra nucleotides into a DNA chain.]]> 2021-04-15 08:24:05 UTC https://padlet.com/whitesharkfw/7f0rta3qa2rjbded/wish/1420057166 saraayad01 https://padlet.com/whitesharkfw/7f0rta3qa2rjbded/wish/1420069846 Translocation means a change in location. It often refers to genetics, when part of a chromosome is transferred to another chromosome. Chromosomes are structures that carry genes, our units of heredity. When this type of translocation occurs, it can cause flaws in chromosomes.
In a translocation, a segment from one chromosome is transferred to a nonhomologous chromosome or to a new site on the same chromosome. Translocations place genes in new linkage relationships and generate chromosomes without normal pairing partners. When scientists compare the genomes of closely related species, they can see that translocations have occurred many times during the course of evolution. However, translocations that give an organism an adaptive advantage are very rare. Translocations are more often associated with negative consequences such as aneuploidy, infertility, or cancer.
To detect them, most diagnostic laboratories use karyotyping, fluorescent in situ hybridization, and reverse transcription PCR.]]> 2021-04-15 08:28:54 UTC https://padlet.com/whitesharkfw/7f0rta3qa2rjbded/wish/1420069846 whitesharkfw https://padlet.com/whitesharkfw/7f0rta3qa2rjbded/wish/1420070826 Chromosome mutation is the process of change that results in rearranged chromosome parts, abnormal numbers of individual chromosomes, or abnormal numbers of chromosome sets.

]]> 2021-04-15 08:29:12 UTC https://padlet.com/whitesharkfw/7f0rta3qa2rjbded/wish/1420070826 taherfarah176 https://padlet.com/whitesharkfw/7f0rta3qa2rjbded/wish/1420076604 Description -> In genetics, a deletion which a part of a chromosome or a sequence of DNA is left out during DNA replication. Any number of nucleotides can be deleted, from a single base to an entire piece of chromosome.
 
 Causes -> Chromosomal deletions occur spontaneously at a low frequency, or are induced by treatment of germ cells (most efficiently, mature or maturing oocytes in the female, and postmeiotic spermatogenic cells in the male) with chromosome-breaking agents, such as acute radiation or certain chemicals.
 
 Example -> Deletions are responsible for an array of genetic disorders, including some cases of male infertility, two thirds of cases of Duchenne muscular dystrophy, and two thirds of cases of cystic fibrosis .Deletion of part of the short arm of chromosome 5 results in Cri du chat syndrome.
 
 Diagnostic technique-> Amplification refractory mutation system (ARMS) PCR: Allele-specific amplification (AS-PCR) or ARMS-PCR is a general technique for the detection of any point mutation or small deletion.]]> 2021-04-15 08:31:12 UTC https://padlet.com/whitesharkfw/7f0rta3qa2rjbded/wish/1420076604 taherfarah176 https://padlet.com/whitesharkfw/7f0rta3qa2rjbded/wish/1420084853 Description -> An inversion is a chromosome rearrangement in which a segment of a chromosome is reversed end to end. An inversion occurs when a single chromosome undergoes breakage and rearrangement within itself. ... Pericentric inversions include the centromere and there is a break point in each arm.
 
 Consequences -> given that inversions have been shown to inhibit recombination in heterokaryotes, chromosomes displaying different orientation are expected to evolve independently and this may lead to distinct gene-expression patterns.
 
 Genetic disorder -> One of the best-characterized recurrent inversions giving rise to disease causes hemophilia A, an X-linked disorder caused by mutations in the factor VIII gene [36]. A recurrent inversion has been found in approximately 43% of patients
diagnostic test -> assays can provide same-day or next-day results, thereby improving the efficiency of diagnosing inversion mutations. Most current inversion assays rely on either IS-PCR or long-range PCR of DNA samples.]]> 2021-04-15 08:34:20 UTC https://padlet.com/whitesharkfw/7f0rta3qa2rjbded/wish/1420084853