This type of mutation occurs when a chromosomal section is separated from the chromosome, rotates 180 degrees, and rejoins the chromosome in an opposite orientation. This type of mutation can affect a gene at many levels. If an inversion disrupts a promoter region, the gene may not be transcribed at all. If the coding sequence is disrupted, a non-functional gene product (protein) may result.
Translocations
This type of chromosomal aberration results when one portion of a chromosome is transferred to another chromosome. This can be a very harmful event if it leads to a subsequent gain or loss of genetic material. Additionally, when a gene from one chromosome moves to another chromosome, large changes in the ability to regulate expression of the gene may occur. Some forms of leukemia result from translocations. In these cases, various genes controlling growth of white blood cells are constantly turned on, leading to an uncontrolled proliferation of these cells and the various clinical manifestations of leukemia.
Lacz mutations*
LacZ mutations are an example of particular mutations found in the LacZ gene of E.coli, which encodes the lactose hydrolyzing enzyme ß-galactosidase. There is a special compound known as X-gal that can be hydrolyzed by ß-galactosidase to release a dark blue pigment. When X-gal is added to the growth medium in petri plates, Lac+ E. coli colonies turn blue, whereas Lac– colonies with mutations in the LacZ gene are white. By screening many colonies on such plates it is possible to isolate a collection of E. coli mutants with alterations in the LacZ gene. PCR amplification of the LacZ gene from each mutant followed by DNA sequencing allows the base changes that cause the LacZ– phenotype to be determined. A very large number of different LacZ mutations can be found, but they can be categorized into three general types: missense, nonsense and frameshift .
Causes of mutations
Mutations are caused by substances that disrupt the chemical structure of DNA or the sequence of its bases. Radiation, various chemicals, and chromosome rearrangements are some of the many sources of mutation.
Mutation rates
All of us are subjected to mutagenic events throughout our lifetime. Depending upon the type of mutation, the frequency ranges from 10-2/cell division to 10-10/cell division. Our cells have numerous mechanisms to repair and/or prevent the propagation of these mutations.
Suppressor mutations*
A powerful mode of genetic analysis is to investigate the types of mutations that can reverse the phenotypic effects of a starting mutation. Say that you start with a mi- λ phage mutant that makes small plaques. After plating a large number of these mutant phages, rare revertants can be isolated by looking for phage that have restored the ability to make large plaques. These revertants could have either been mutated such that the starting mutation was reversed, or they could have acquired a new mutation that somehow compensates for the starting mutation. The possibilities are:
Questions & Answers
A golfer on a fairway is 70 m away from the green, which sits below the level of the fairway by 20 m. If the golfer hits the ball at an angle of 40° with an initial speed of 20 m/s, how close to the green does she come?
A mouse of mass 200 g falls 100 m down a vertical mine shaft and lands at the bottom with a speed of 8.0 m/s. During its fall, how much work is done on the mouse by air resistance
Chemistry is a branch of science that deals with the study of matter,it composition,it structure and the changes it undergoes
Adjei
please, I'm a physics student and I need help in physics
Adjanou
chemistry could also be understood like the sexual attraction/repulsion of the male and female elements. the reaction varies depending on the energy differences of each given gender. + masculine -female.
Pedro
A ball is thrown straight up.it passes a 2.0m high window 7.50 m off the ground on it path up and takes 1.30 s to go past the window.what was the ball initial velocity
2. A sled plus passenger with total mass 50 kg is pulled 20 m across the snow (0.20) at constant velocity by a force directed 25° above the horizontal. Calculate (a) the work of the applied force, (b) the work of friction, and (c) the total work.
you have been hired as an espert witness in a court case involving an automobile accident. the accident involved car A of mass 1500kg which crashed into stationary car B of mass 1100kg. the driver of car A applied his brakes 15 m before he skidded and crashed into car B. after the collision, car A s
can someone explain to me, an ignorant high school student, why the trend of the graph doesn't follow the fact that the higher frequency a sound wave is, the more power it is, hence, making me think the phons output would follow this general trend?
Nevermind i just realied that the graph is the phons output for a person with normal hearing and not just the phons output of the sound waves power, I should read the entire thing next time
Joseph
Follow up question, does anyone know where I can find a graph that accuretly depicts the actual relative "power" output of sound over its frequency instead of just humans hearing
Joseph
"Generation of electrical energy from sound energy | IEEE Conference Publication | IEEE Xplore" ***ieeexplore.ieee.org/document/7150687?reload=true
A string is 3.00 m long with a mass of 5.00 g. The string is held taut with a tension of 500.00 N applied to the string. A pulse is sent down the string. How long does it take the pulse to travel the 3.00 m of the string?
