Notes 4 Flashcards
Mutations
A change in the DNA of a cell
Types of Mutations
- Gene Mutations
- Chromosome Mutations
Gene Mutations
A change in the DNA by altering one or more DNA nucleotides
Substitution
A DNA nucleotide is replaced by another nucleotide
Framshift
The addition or Deletion of a DNA nucleotide causes the DNA to be read out of a sequence
Chromosome Mutations
A change in the chromosome structure or number
Deletion
A piece of a chromosome breaks off and the information is lossed
Translocation
A piece of one chromosome breaks off and reattaches to a different chromosome
Nondisjunction
When homologous chromosomes do not separate during anaphase causing the cell to have extra or missing chromosomes (causes down syndrome)
Mutagens
Environmental factors that cause mutations
(i.e. cigarette smoke, asbestos, chemicals, radiation)
Effects of Mutations
May be harmful, helpful, or have no effect(neutral)
Detecting Genetic Disorders
- Genetic Counseling
2.Ultrasound
3.Amniocentesis - Karyotyping
Genetic Counseling
Uses pedigrees to predict possible genetic problems
Ultrasound
Sound waves produce an image of the fetus showing physical problems
Amniocentesis
A sample of amniotic fluid is used to check the baby’s DNA for genetic disorders