Name: ______________________________________ Period: ________________
What is a mutation?
• Changes in the genetic material (DNA).
There are two types of mutations that can occur in gamete cells:
1. Gene mutation: affect only one gene. Examples: point and frameshift.
2. Chromosomal mutation: affect the number or structure of chromosomes. Usually involves many, many genes.
5 types of Chromosomal Mutations:
Deletion: Involves the loss of all or part of a chromosome.
Examples: Cri du Chat syndrome, Angelman’s syndrome, Prader-Willi syndrome, Miller-Dieker syndrome
Duplication: Involves the production of extra copies of parts of the chromosome
Examples: Fragile X syndrome, Beckwith-Wiedeman syndrome
Inversion: Reverses the direction of parts of a chromosome.
Translocation: When one part of a chromosome breaks off and attaches to another chromosome.
Example: Edward’s syndrome
• Means “not coming apart”.
• When homologous chromosomes fail to separate properly during meiosis.
• Results in abnormal numbers of chromosomes. Normal is two of each type of chromosome.
• Trisomy means a person has an extra copy of a chromosome.
• Monosomy means a person is missing a copy of a chromosome.
Examples of Trisomy: Down syndrome, Trisomy 13, Cat eye syndrome (tetrasomy), Klineflelter’s syndrome
Example of Monosomy: Turner’s syndrome