Eukaryotic Chromosomes and Gene Regulation

These flashcards cover the key concepts related to eukaryotic chromosomes, chromatin structure, gene expression regulation, and techniques used in genetics.

Eukaryotic chromosome

Contains a single molecule of linear double stranded DNA held compactly by histone proteins.

Nucleosome

A structure where DNA is wrapped twice around a core of histones, with H1 controlling where DNA enters and exits.

Chromatin

The complex of DNA and proteins, mainly histones, that constitutes chromosomes.

Giemsa stain

A technique that produces specific G bands in metaphase chromosomes for identifying chromosomes and gene locations.

FISH (Fluorescence In Situ Hybridization)

A method used to localize specific DNA sequences with respect to chromosomal bands.

Condensins

Proteins that shape mitotic chromosomes by extruding loops of nucleosomal chromatin.

Heterochromatin

A tightly packed form of DNA that prevents transcription and silences genes.

Position-effect variegation

A phenomenon where the expression of a gene is affected by its position relative to heterochromatin.

Xist gene

Responsible for X chromosome inactivation through the production of a long noncoding RNA that coats the chromosome.

Telomeres

Structures at the ends of chromosomes that protect them from degradation and enable replication.

Cohesin complexes

Protein complexes that hold sister chromatids together during cell division.

Kinetochores

Structures at the centromere where spindle fibers attach during cell division.

Transcriptional regulation

The process of modulating gene expression by changes in chromatin structure and nucleosome position.

Artificial chromosomes

Constructed DNA structures used as cloning vectors, requiring an origin of replication, centromere, and telomeres.

Shelterin proteins

Proteins that bind to telomeres to protect them from degradation.