Chromosome Structure and Number

These flashcards cover key vocabulary related to chromosome structure and number, including terminology related to mutations, chromosome types, and their implications in genetics.

Chromosome

Cellular structures that contain genetic material (DNA) with associated proteins.

Karyotyping

A process that helps identify changes in chromosomes both across species and populations and within individual organisms.

Deletion

A type of chromosomal mutation where a segment of chromosomal material is deleted or is missing.

Duplication

A chromosomal mutation that results in extra genetic material, usually less harmful than deletion.

Inversion

A chromosomal mutation where a segment is flipped in opposite direction and reinserted; total amount of genetic material remains the same.

Translocation

A chromosomal mutation where an extra chromosome segment attaches to a non-homologous chromosome.

Aneuploidy

A condition where organisms have different numbers of each kind of chromosome, often detrimental to organisms.

Nondisjunction

Failure of chromosomes to separate properly during meiosis, leading to aneuploidy.

Ploidy

The number of chromosome sets in a cell; can vary among organisms (e.g., diploid, triploid, tetraploid).

C-value paradox

The observation that genome size does not correlate with organism complexity.

Transposable elements

Segments of DNA that have the ability to move within a genome, also known as 'jumping genes.'

Retrotransposition

A type of transposition that involves the RNA intermediate being synthesized back into DNA for insertion into the genome.

Euchromatin

A less compacted form of chromatin that contains actively transcribed genes.

Heterochromatin

A more compacted form of chromatin that generally has fewer genes and a more closed structure.

Condensin

Proteins that help to condense chromatin and regulate chromosome structure.

Cohesin

A multiprotein complex involved in binding sister chromatids together during cell division.

Gene duplication

A process that can lead to the evolution of gene families, allowing one gene copy to evolve separately from another.

Terminal deletion

A type of deletion where the end of a chromosome is lost.

Interstitial deletion

A deletion that occurs in the middle of a chromosome, possibly due to crossing over.

Centromere

The region of a chromosome where sister chromatids are joined and which is important for chromosome segregation.

Phenotypic evolution

Changes in phenotype that can result from gene duplication and mutations over generations.