Chapter 8 Genetic Variation Flashcards
Genetic Variation
genetic differences among SAME or DIFFERENT species
Allele Variation
difference in species genes
Chromosome Identified 3 ways:
Location of Centromere
Size
Banding Pattern
Metacentic
Centromere located in center of chromosome
Submetacentric
Centromere slightly off center
acrocentric
Centromere way off center
Telocentric
Centromere at one end (so short arm does not exist)
Short arm represented by letter?
P
Long arm represented by letter?
Q
In a Karyotype chromosomes are organized based on what?
- numbered according to size
- short arm on top
- largest have smallest number
Deletion
change in total number of chromosomes resulting from a deletion a segment of genetic material (also referred to as deficiency)
Duplication
Change in total number of chromosomes resulting from section of chromosome being repeated
Inversion
chromosomal rearrangements- changes direction of genetic material
Translocation
chromosomal rearrangement-one segment of chromosome becomes attached to another chromosome OR another part of same chromosome
Simple Translocation
One segment of a chromosome moves to another segment
Reciprocal Translocation
Two chromosomes EXCHANGE pieces
Terminal Deletion
A chromosome breaks in two pieces and the end of a chromosome is lost
Interstitial Deletion
A chromosome breaks in to three pieces and the center piece is lost
Cri-Du Chat Syndrome
Deletion in short arm of chromosome 5 resulting in mental deficiency, facial abnormality, and catlike cry at birth
Prader Willi Syndrome and Angelman Syndrome
Deletion in chromosome 15
Repetitive Sequence
homologous chromosome carrying identical or similar fragments of genetic material
Nonallelic homologous recombination
two repetitive sequences align causing a duplication in one chromosome and a deletion in the other due to the misalignment
Gene Duplication
number of genes at specific location duplicates
Charchat Marie-Tooth
Small duplication in chromosome 15 causing abnormality in development of hands and feet
Gene Family
Two or more genes similar to each other that were created from the same ancestral gene