Unit 3-Molecular Genetics Lesson 7-2.0-5.0 Flashcards
What are mutations?
Changes in the DNA sequence
What are the causes of mutations?
Various mechanisms such as radiation, synthetic chemicals, incorrect replication, random mutations
What are small scale mutations?
Mutations that occur to an individual base pair
What is one example of a small scale mutation?
Point Mutations
What is a point mutation? #1
A mutation that occurs when one base is substituted for another base
State the purines and pyrimidines:
Purines:
Adenine
Guanine
Pyrimidine:
Thymine
Cytosine
Uracil
Example of a Point Mutation Substitution
A purine for a purine or a pyrimidine for a pyrimidine
What can a point mutation be? #2 and #3
It can be an insertion (addition of a base pair) or a deletion (subtraction of a base pair)
Inversion of two-adjoining base pairs
What is an example of a point mutation? #2 and #3
Β-thalassemia cannot synthesize β-globin, the mutated gene codes for stop codons and causes individuals to have small erythrocytes that rupture easily
What are single nucleotide polymorphisms (SNPs)?
Differences in individuals within a population that are caused by point mutations
What can the effects of small scale mutations include?
Positive, Negative, Severe or No Effect
What are the four categories of small scale mutation?
Missense, Nonsense, Silent, Frameshift
What is a silent mutation?
A mutation that has no effect on the protein sequence.
What is missense mutation?
Results in an amino acid substitution
What is a nonsense mutation?
Substitutes a stop codon for an amino acid.
