Structure of chromosomes notes

chromosomes

Pair of homologous chromosomes and chromatids. Vector illustrationchromosomes#homologous#Pair#illustration

In the nucleus of each cell, DNA is packaged into thread-like structures called chromosomes. Each chromosome consists of DNA tightly coiled around proteins called histones that support its structure. Chromosomes play a vital role in heredity, mutation, variation, and evolutionary development of species.

This picture shows the organization of chromatin including DNA's double helix structure and how DNA winds around core particles to form nucleosomes. From there, the DNA continues to wind upon its self until a chromosome is created. The function of genes in DNA is to code for the creation of proteins to be used in the body. A genome is all the genes one person has. For example, the human genome is approx. 30-35,000 genes. (Picture obtained from McGraw-Hill Connect).

Chromosome structure

Vector scientific medical illustration of the structure of chromosomes. Chromosome composition, description, and structure. Centromere, telomere, chromatids, p short and q long arm, and DNA molecule. Stock Vector | Adobe Stock

The word chromosome is derived from the Greek language: chroma (colour) and soma (body). Structure of the chromosome in relation to the phase of the cell cycle: Each metaphase chromosome is composed of 2 chromatids held together at the centromere. The chromosome is divided by a constriction, the centromere into 2 arms; short and long (p and q respectively).

The NASA Twins study - featuring astronaut twins Scott and Mark Kelly - was the perfect space experiment. Scott spent a year in space aboard the International Space Station. Mark remained on Earth. The results?

Chromosome Structure | CIE AS Biology Revision Notes 2025 | Save My Exams