Chromosome Structure: Telomeres, Centromeres, and Chromatids

2. In eukaryotic cells the DNA is found in compartments in the nucleus in the form of numerous linear molecules, which, together with certain proteins, make up chromatin. When the cell starts to divide, the chromatin condenses to form chromosomes. CHROMOSOME STRUCTURE CHROMOSOME TYPES Click on each square to find out more.

3. Chromosome structure Telomere • A chromosome has two arms separated by a centromere. Short arm Centromere • The ends of the arms are called telomeres. Long arm • The arms are divided in two, and each part is known as a chromatid. Chromatids Go back to the Start menu

4. ACROCENTRIC TELOCENTRIC METACENTRIC SUBMETACENTRIC The centromere is halfway along the chromosome and the two arms are of the same length. • One arm is longer than the other. On division they take on an “L” shape as they are pulled apart. • The centromere is very close to one end, meaning that one arm is much shorter than the other. • The centromere is at the end of the chromosome, so the chromosome has only one arm. Centromere Centromere Centromere Centromere Chromosome types • Different types of chromosomes can be distinguished according to the position of the centromere: Go back to the Start menu