Variation in Chromosome Structure & Number

A series of flashcards to aid in understanding key concepts related to variations in chromosome structure and number.

Genetic variation

Refers to genetic differences between members of the same species or those of different species.

Allelic variations

Differences due to mutations in particular genes.

Chromosomal aberrations

Substantial changes in chromosome structure or number.

Cytogenetics

The field of genetics that involves the microscopic examination of chromosomes.

Deficiency (deletion)

The loss of a chromosomal segment.

Duplication

The repetition of a chromosomal segment compared to the normal parent chromosome.

Inversion

A change in the direction of part of the genetic material along a single chromosome.

Translocation

A segment of one chromosome becomes attached to a different chromosome.

Simple translocation

One way transfer where a piece of a chromosome is attached to another chromosome.

Reciprocal translocation

Two way transfer where two different types of chromosomes exchange pieces.

Phenotypic consequences of deficiencies

Depends on the size of the deletion and the chromosomal material deleted.

Duplications and phenotypic consequences

Tend to be correlated to size; have less harmful effects than deletions of comparable size.

Paralogs

Homologous genes that may differ due to gradual accumulation of DNA mutations.

Globin gene family

A family of genes that encode subunits of proteins that bind oxygen, including myoglobins and hemoglobins.

Myoglobin

A protein that stores oxygen in muscle cells.

Hemoglobins

Proteins that bind and transport oxygen via red blood cells.

Paracentric inversion

A type of inversion that does not include the centromere.

Pericentric inversion

A type of inversion that includes the centromere.

Chromosomal translocation

Occurs when a segment of one chromosome becomes attached to another.