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Mutations and DNA Technology. What is a mutation?. A mutation is a change in DNA Two types of mutations are gene mutations and chromosome mutations. Gene mutations. A POINT MUTATION is a mutation that affects one nucleotide or one base. Sometimes your cell catches it when proofreading.
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What is a mutation? • A mutation is a change in DNA • Two types of mutations are gene mutations and chromosome mutations.
Gene mutations • A POINT MUTATION is a mutation that affects one nucleotide or one base. • Sometimes your cell catches it when proofreading. • What will happen? • The wrong amino acid may be put into place. • Example: sickle cell anemia • YOU ARE FAT >>>> YOU ARE CAT • ATA TAG CCA >>>>> AAA TAG CCA
A FRAMESHIFT mutation involves the insertion or deletion of a nucleotide or base. • This causes a shift in the whole sequence. • This usually causes something bad to happen. • THE CAT ATE THE RAT. >> • THC ATA TET HER AT • ATT CCA TAG >>>> ATC CAT AG • Every amino acid put in will be wrong.
Chromosomal mutations • Occurs during meiosis. • The resulting gamete will have the wrong number of chromosomes. • These tend to increase as parents get older.
There is only one X chromosome on the 23rd pair. • This is a female. (1/2500) • She is underdeveloped. • She is short . 4’7” • May have webbed neck, low hairline on back of head, drooping eyelids, lower set ears, edema of hands and feet. • Usually sterile.
What about a person with only one Y chromosome? (lacks an X) • He will not live. Why?
Male • 1/500-1/1000 males • Tall • Reduced fertility • Less muscle control and coordination • Less facial hair and broader hips • Language and reading difficulty
XYY syndrome • Tall male • May not have any phenotypic differences • Was associated with criminal or antisocial behavior.
Trisomy • Can be any chromosome. • Usually cause extreme effects in people and animals. • Plants survive.
Are all mutations bad? • Some are bad. • Some are harmless • Some may actually be beneficial.
Mutations in body cells affect the organism. • Mutations in gametes affect the offspring.
Mutagens • A mutagen is something that causes a mutation. • Industrial chemicals • UV light • Any radiation • Drugs • Chemicals
DNA fingerprinting • Every person has their own unique DNA fingerprint. • Can be used for identification. • Can be used to establish paternity. • Study human migration.
Cloning • Genetically identical copy of an organism. • Can be done easily with plants. (Also occurs naturally.) • Can be done with animals. • Should it be done with people.
the boys from brazil - rabbit cloning – YouTube • GCSE Science Revision - Cloning Dolly The Sheep - YouTube
Genetic engineering • Taking DNA from one organism and inserting it into the DNA of another organisms. This is called recombinant DNA. • The new organism is a transgenic organism. • We do this to make insulin. • We take an insulin gene from a person and put it into the DNA of a bacteria. What do we get? Bacteria that produce insulin.
We have created plants that are resistant to frost, diseases and insects. • We can increase crop yields. • We have developed animals for research.
Human genome project • Sequence the human genome. • Find all of the genes on all of the chromosomes.
Gene therapy • Repair defective genes. • Still very experimental. • Should we do it?