Exam 1- Mutations and DNA Flashcards
What is Personal Genomics?
Looking at the sequence of individuals DNA in order to determine disease risk, personalize medicine, or plan pregnancy
What is Personalized Medicine?
Using individual genomics to specifically tailor treatment to the individual
What Was the 4 Criteria Scientists Needed for DNA?
- Must contain complex information
- Must replicate faithfully
- Must encode the phenotype
- Must be able to vary
What did the 1928 Griffith Experiment Determine?
There was some sort of genetic code that was passed down across generations that contained complex information… they just didn’t understand what it was
What did the 1944 Avery, MacLeod, and McCarty Experiment Determine?
Identified DNA as the hereditary molecule passed down over generations containing code
What did the 1952 Hershey-Chase Experiment Determine?
Proved that DNA was the hereditary molecule passes by the infecting phage into the host cell and inherited by the phylogeny base
What are Nucleotides?
The building blocks of DNA
What are Nucleotides Made of?
Phosphate, Sugar, and nitrogenous base
What is DNA?
A polymer of nucleic acids on a sugar-phosphate backbone
What are Purines?
Adenine and Guanine
What are Pyrimidines?
Cytosine and Thymine
What is the Base Pairing in DNA?
A-T and C-G
What did Chargaff Discover?
% A = % T and % G = % C in double stranded genomes. But A+T does not equal G+C
What are the Characteristics of the Genetic Code (4)
- Non Overlapping
- Triplet
- No gaps in the code (start-stop)
- 20 amino acids
How Many Nucleotides in a Codon?
3
What is a Genotype?
Genetic code for a gene
What is a Phenotype?
Physical traits coded by genes
What are the Components of a Gene?
- Introns
- Exons
- Promoter Region
- Enhancer & Silencer Regions
- Untranslated Regions
Where are Enhancer and Promoter Regions Located?
All throughout the DNA
What are Enhancer and Promoter Regions?
Regulatory Regions
What do Splice Sites do?
Split coding Exons and non-coding Introns
Where do Somatic Mutations Occur?
Non-reproductive Cells
Where do Gametic Mutations Occur?
Reproductive Cells (Germ-Line Mutations)
What are Spontaneous Mutations?
Natural mutations that occur randomly during transcription or proofreading. They are infrequent and inherited if in gametes.
What are Induced Mutations?
Mutations caused by high energy radiation or chemicals. They are higher frequency than spontaneous and have the same inheritance pattern as spontaneous mutations.
What are Base Substitution Mutations?
Transition vs Transversion mutations
What is a Transition Mutation?
Purine for Purine or Pyrimidine for Pyrimidine
What is a Transversion Mutation?
Purine for Pyrimidine or Pyrimidine for Purine
What are Insertion or Deletion Mutations?
Frameshift inducing mutations (groups of 1-2) or In-Frame mutations (groups of 3)
What are Expanding Nucleotide Repeats?
Inserts copies of set of nucleotides, this can disrupt protein function. (Example- Huntington’s Disease)
What are Forward Mutations?
Mutations that convert wild-type allele to mutant allele
What are Reverse Mutations?
Mutations that convert mutants to near wild-type
What is True Reversion?
The exact wild-type sequence restored, Mutation at the same base pair or same codon
What is Intragenic Reversion?
Mutation somewhere else in the gene, near wild-type allele (most common)
What is Second-Site Reversion?
Mutation in a different gene can potentially restore wild-type phenotype (least common)
What is Mutation Rate Affected by?
- Size of the gene
- Rate that mismatched bases are incorporated into DNA
- Efficiency of repairing damage
- Organism life cycle