Genetics Flashcards
(37 cards)
What impact do mutations have on the DNA fragments?
Makes them different sizes
Can cause a sequence to no longer act as a restriction site
What is restriction fragment analysis?
Examines size distribution of DNA restriction fragments cut by restriction enzymes
What are the five uses for restriction fragment analysis?
- Examine variation within individuals
- Determine relatedness of groups
- Identify genes associated with mutations
- DNA fingerprinting
- Identify carriers of genetic disorders
What regions of DNA does human fingerprinting examine?
Non coding
Highly variable
Repeated
What does the number of alleles tell you?
The number of repeats which is the size of the DNA fragment
What is the five step procedure for DNA fingerprinting?
- DNA sample is amplified using PCR
- Sample is cut with restriction enzymes
- Fragments separated by gel electrophoresis
- DNA separated into single strands and bound to surface
- Proves are used to find fragments with repeated sequences
Paternity testing
Alleles found in a child must be present in one or both parents
What are the potential problems with fingerprinting?
Contamination of sample
Inaccurate reporting
Relatives may have same alleles
What is the solution to relatives and DNA testing?
Using several different repeats and testing for variation
What are GMO’s?
Artificially modified genomes of organisms
What are the two types of modifications of GMO’s?
- Modification of existing genomes
2. Transgenic organisms
What are transgenic organisms?
Organisms with genes from two or more species combined
Example roundup ready crops
What are two genetic technologies that treat genetic disorders?
Supplying missing gene product with working copies of the gene
Gene therapy- extracting cells, infect cells, place back in patient * only works for a while
What are seven basic methods of genetic technologies?
Replication of DNA Locating nucleotide sequences Cutting and joining sections of DNA Separating pieces of DNA Pasting DNA into an organism Sequencing sections of DNA Locating sequences of DNA
What enzyme does polymerase chain reaction use?
Heat resistant DNA polymerase
What are the steps in PCR?
- Sample DNA, primers, DNA polymerase and nucleotides combined
- Heat strands to separate them
- Strands are cooled to allow primers to bind to each strand
- DNA polymerase synthesizes new strands
- Repeat
What parts of DNA can be amplified?
Small regions between the primers
What do restriction enzymes do?
Cut DNA into fragments
What are the steps of joining and cutting DNA?
Cut with restriction enzymes
Cut at restriction site
DNA ligase bonds two parts together
How do you combine DNA from different organisms?
- Must cut with same restriction enzymes
- DNA from each is mixed which allows H bonds to form
- DNA ligase forms the sugar phosphate backbone
What is gel electrophoresis?
A process to separate DNA
Draws DNA to positive charges
How is gel electrophoresis done?
- Place mixture of DNA on gel
- Electric current is applied
- DNA separates by size
- DNA is stained
What are uses for gel electrophoresis?
Identify organisms
Locate and separate genes
Sequence DNA
What are three methods of pasting DNA into organisms?
Plasmids
Viruses
Mechanical methods
