what is gene mutation?

Answer 1

A gene mutation is a change in the sequence and/ or structure in the DNA responsible for a biological mechanism in an organism. The central dogma of biology states that DNA gets turned into RNA, and RNA gets turned into amino acid chains called proteins. And proteins are what organisms are primarily is made out of. The specificity of the sequence of amino acids determines what kind of protein it will become. That specificity comes from the sequence of RNA, which in turn came from the DNA.

Everyday, organisms are hit with mutagens (agents that physically change DNA) from a variety of sources (i.e. UV light, radioactive materials, and cigarette smoke to name a few). When these mutagens come in contact with living cells, the DNA can physically break or create abnormal bonds between atoms in the DNA. This process can result in a different nucleic acid at that position, a deletion, or even an insertion of a new nucleic acid. DNA sequence is changed, RNA is changed, and proteins are changed.

Furthermore, a cytosine (the C of DNA) that has been methylated (a carbon group attached to it) can spontaneously change to a thymine (the T in DNA) through a process called deamination. Gradually over time, genomes can lose their cytosines if those cytosines are not evolutionarily important.

Gene mutations can also come from DNA changes that occur in regions that do not code for RNA. There are regulatory regions in DNA that tell the RNA making machinery when, where, and how to make RNA. Any changes in those pieces of DNA can also affect how a protein is expressed.

So how does life keep living with the constant bombardment of mutagens? Over time, life has evolved mechanims and redundancies that lessen and fix the damaged caused by mutagens.

Most gene mutations result in negative effects. With enough DNA changes cancers can develop because some genes have been shut down, while others have been expressed more than normal.

However, once in a while mutations can prove to be beneficial. Take for example the gene lactase. Lactase helps break down lactose which is found in milk. When lactase is present, we are getting the most nutrition out of milk. All infants express lactase, which makes sense because we are growing rapidly at that time and need all the nutrition we can get. However, as we get older, the lactase gene shuts itself off because we do not depend on our mother's milk, and become lactose intolerant. Some people have a mutation that causes the lactase gene to be expressed at all times, even as adults and thus they can always get the most nutrition out of milk. This would be very beneficial for early farmers because a poor crop could be supplemented by cow's milk.

Answer 2

Gene mutation is a change in the nucleotide base of and genetic sequence. There are many types of gene mutation. Some of them include base substitution, deletion, addition, inversion.

Depending upon the condition, The genetic mutation may not cause a shift in the reading frame of the gene and the resultant protein translated will still be relatively similar. However, if the gene mutation results in a frameshift, then any change in the reading frame of the gene during protein synthesis will produce a non-functional protein.

Answer 3

It is when a gene that is passed down from both parents gets mutated or changed into something differerent in a child. For example, a mother has blue eyes, an father has green, and the child ends up with brown eyes. That is a gene mutation.

Answer 4

A mutation in the DNA of a gene, as opposed to a mutation in a section of "junk" DNA.

Answer 5

There are many, many different types of gene mutations, but typically they are simply a slight difference in the DNA. These differences can result in various physical differences or other disorders. I.E. Down syndrome, kleinfeilder's syndrome, the "elephant disease", and many others.

Answer 6

when gene (simmons) of kiss would go from regular guy to the dragon man.


:D

most times it's cancer. other times.. well long term mutations that may / have occurred is when the evolution of the chemical make up of a person makes them from regular WWF wrestler to dashing up and coming entrepreneur.

Answer 7

This is a situation whereby the structure of the DNA strand is altered by either deletion,substitution or inversion...resulting in a different structure fromthe original

Answer 8

Please see the webpage for more details on Gene Mutation.

Answer 9

A change in the amino acid sequence in DNA.

Answer 10

check this out
http://ghr.nlm.nih.gov/handbook/mutationsanddisorders/genemutation