Genetic Variation and Chromosome Structure

These flashcards cover key terms and concepts related to chromosome structure variations and genetic variation within species, helping students memorize important vocabulary and definitions.

Genetic Variation

Differences in DNA sequences among individuals within a species.

Chromosome Structure

The organization and arrangement of DNA within chromosomes.

Chromosomal Variations

Changes in the structure, number, and arrangement of chromosomes.

Short arm of a chromosome

Denoted by 'p' in chromosome notation.

Long arm of a chromosome

Denoted by 'q' in chromosome notation.

Terminal deletion

Loss of genetic material at the end of a chromosome.

Interstitial deletion

Loss of a segment from the middle of a chromosome.

Cri-du-chat syndrome

A genetic disorder caused by a deletion of a portion of chromosome 5.

Gene duplication

The process where a segment of DNA is copied, resulting in multiple gene copies.

Misalignment during crossing over

Can cause gene duplications, contributing to evolutionary processes.

Gene family

A group of similar genes that arose from a single ancestral gene through duplication.

Paralogs

Homologous genes within a species arising from gene duplication events.

Globin gene family

A group of genes related to oxygen transport, differing by developmental stage.

Chromosomal inversion

A structural change where a segment of DNA reverses its orientation on a chromosome.

Position effect

Altered gene expression due to changes in regulatory elements from inversions.

Pericentric inversion

An inversion that includes the centromere with breakpoints on both chromosome arms.

Paracentric inversion

An inversion that does not include the centromere.

Translocation

The transfer of genetic material between chromosomes.

Reciprocal translocation

Exchange of genetic material between two non-homologous chromosomes.

Balanced translocation

Exchange of chromosomal segments without any net gain or loss of genetic material.

Unbalanced translocation

Exchange of chromosomal material resulting in extra or missing genes.

Robertsonian translocation

Translocations that occur between acrocentric chromosomes.

Euploidy

The state of having one or more complete sets of chromosomes.

Diploid

Having two sets of chromosomes, the normal state for human cells.

Triploidy

The condition of having three sets of chromosomes.

Tetraploidy

The condition of having four complete sets of chromosomes.

Polyploidy

Having more than two complete sets of chromosomes.

Endopolyploidy

A phenomenon where somatic cells possess multiple sets of chromosomes.

Polytene chromosomes

Bundles of many copies of the same chromosome used in genetic studies.

Allodiploid

An organism with two sets of chromosomes from two different species.

Allotetraploid

An organism with four sets of chromosomes from two species.

Aneuploidy

Presence of an abnormal number of chromosomes, such as in Down syndrome.

Klinefelter syndrome

A condition in males characterized by an extra X chromosome (XXY).

Mosaicism

Presence of two or more genetically different cell lines in an individual due to nondisjunction.

Copy Number Variation

Variations in the number of copies of a specific DNA sequence in the genome.

Mitotic nondisjunction

Failure of chromosome separation during mitosis, leading to aneuploidy.