Mutations Flashcards
Gene Mutation
A single gene is altered, destroying or changing the traits normally produced by that gene
Chromosomal Mutations
All or parts of a chromosome are affected/altered
Somatic (body cells) mutations
These are when body cells are affected.
- Only the individual with the mutation is affected.
- Mutation passed on during mitosis to the daughter cells.
Germinal/Germline mutations
Occur when the repro cells are affected by the mutation.
- Mutation may be passed on through gametes
- Individual may not be affected
What are mutagens?
Substances that cause mutations
What are the known mutagens?
Mustard gas
Formaldehyde
Sulphur Dioxide
Some Antibiotics
Radiation
After effects of atomic and nuclear explosions
Albinism
Due to one missing protein there is an absence of pigments on the skin, hair and eyes
Duchenne form of muscular dystrophy
Caused by either: mutation in mother or male zygote
Results in wasting of muscle tissue - replaced by fatty tissue as boys get older
Cystic Fibrosis
Mutation on chromosome 7, controls manufacture of 1480 amino acids that make up a protein that regulates the passage of chloride ions across the cell membrane
Can cause: persistent coughing, salty-tasting skin, wheezing, and digestive problems.
Deletion
Loss of a piece of DNA from a chromosome.
Deletion of a gene or part of a gene can lead to a disease or abnormality.
Duplication
Production of one or more copies of any piece of DNA, including a gene or even an entire chromosome.
Insertion
A type of chromosomal abnormality in which a DNA sequence is inserted into a gene, disrupting the normal structure and function of that gene.
Translocation
Breakage and removal of a large segment of DNA from one chromosome, followed by the segment’s attachment to a different chromosome.
Inversions
The order of the genes is changed on the chromosome, as a result of a chromosome break.
Non-Disjunctions
A change in the chromosome number of meiotic daughter cells.
Trisomy
Condition where an individual inherits an extra copy of a chromosome.
Trisomy 21
Down Syndrome -
Extra copy of chromosome 21 results in characteristic facial appearance variable degrees of intellectual disability and physical abnormalities.
Trisomy 13
Patau Syndrome
Extra chromosome 13. Produces individuals with intellectual disability, a small head, extra fingers or toes, a cleft palate and/or cleft lip and malformations of the ears and eyes.
Trisomy 18
Edwards Syndrome
Results in an intellectual disability & defects in the eyes, ears, hands and head.
Monosomy
Individual is missing a chromosome.
Results in severe malformations and often miscarriage.
Partial Trisomy
Part of an extra chromosome is attached to one of the other chromosomes.
Trisomy on sex chromosomes
XXY or XYY
Effects of Mutations
The variations caused by mutations may have advantageous or disadvantageous effects.
Advantageous Mutations
Sickle Cells trait
Resistance to Atherosclerosis
Immunity to HIV/AIDS
