Question | Answer |
Supercoiling | When the two strands of DNA are twisted around each other they coil up. |
Chromatin | DNA plus protein. |
Heterochromatin | highly condensed, darkly staining chromatin |
Euchromatin | less dense, lightly staining, transcriptionally active, chromatin. |
Solenoid coiling | Nucleosomes will wrap around each other to form tubes |
Histones | proteins that form octameric complexes, which eukaryotic DNA wraps around. They are the most abundant |
Nucleosomes | histone octamers and associated DNA, not including the linker regions |
Histone 1 (H1) | binds linkers together |
Histones are acids or bases? | bases! They are positively charged molecules |
Solenoid tangling | Chromosomal condensation during prophase also involves solenoids tangling in complex patterns to form the mitotic (or meiotic) chromosomes. |
Scaffoid Proteins | Ties the solenoids together to form the condensed, mitotic chromosomes.
Maintain supercoiling |
Bands in mitotic chromosomes | dark staining regions, which are believed to consist of more tightly packed DNA. |
Structure of Mitotic (Meiotic) Chromosomes | Bands
Centromeres
Arms
Telomeres |
Centromere | Region of a chromosome that is bound to the mitotic spindle. Dark bands are called G bands |
metacentric chromosome | central centromeres |
Submetacentric chromosome | off center centromere |
Acrocentric | Centromere towards end with a satellite at the end |
Telocentric | Centromere at the end. not found in humans |
Arms | chromosomes are divided by the centromere into two regions known as arms.
Shorter arm is p arm (petite)
Larger arm is q arm |
Telomeres | The ends of chromosomes |
Karyotype | Number, size and banding patterns of all mitotic chromosomes. |
Karyotype numbers | Larger to smaller |