Lecture 16: Errors in Meiosis

These flashcards cover key vocabulary and definitions related to errors in meiosis, chromosomal abnormalities, and their implications for human genetics.

Nondisjunction

The failure of chromosomes to separate properly during meiosis.

Aneuploidy

A condition in which there is an abnormal number of a particular chromosome resulting from nondisjunction.

Monosomy

A condition where a zygote has only one chromosome from a pair (2n-1).

Trisomy

A condition where a zygote has three copies of a particular chromosome (2n+1).

Polyploidy

Possession of more than two complete sets of chromosomes, often resulting from nondisjunction.

Chromosomal Aberrations

Changes in chromosome structure or number that can lead to genetic disorders.

Deletion

The loss of a portion of a chromosome, which can lead to severe effects.

Duplication

When a segment of a chromosome is copied and attached to the chromosome, increasing the gene dosage.

Inversion

A chromosomal rearrangement in which a segment of a chromosome is reversed end to end.

Translocation

The attachment of a chromosome segment to a nonhomologous chromosome.

Karyotype

A visual representation of an individual's complete set of chromosomes.

Down Syndrome

A genetic disorder caused by trisomy of chromosome 21, characterized by developmental delays.

Klinefelter Syndrome

A genetic condition in males caused by an extra X chromosome (XXY), resulting in 47 chromosomes.

Turner Syndrome

A genetic condition in females characterized by the absence of one X chromosome (XO), resulting in 45 chromosomes.

Patau Syndrome

A genetic disorder caused by trisomy of chromosome 13, resulting in severe developmental issues.

Edwards Syndrome

A genetic disorder caused by trisomy of chromosome 18, leading to severe developmental challenges.

Fertility in Polyploidy

Many polyploids are infertile due to an odd number of chromosome sets.

Klinefelter syndrome incidence

Approximately 1 in 1000 male births is affected by Klinefelter syndrome.

Meiotic Errors

Mistakes during meiosis that can lead to aneuploidy and birth defects.

Philadelphia Chromosome

A chromosomal abnormality resulting from a translocation between chromosomes 9 and 22, associated with chronic myeloid leukemia.