Human Chromosomes

Overview and Definition

Human chromosomes are the structures within cells that hold the majority of the organism’s genetic material.
Chromosomes are composed of DNA (deoxyribonucleic acid) and protein.
Each cell in the human body, except sperm and egg cells, contains 46 chromosomes.

Structure of Chromosomes

Chromosomes are made up of a centromere and two chromatids.
The centromere is the point where two chromatids, or sister chromosomes, are attached.
A chromatid consists of a DNA molecule and associated proteins.

Types of Chromosomes

Humans have 23 pairs of chromosomes.
These include 22 pairs of autosomes and one pair of sex chromosomes.
Autosomes are those that are not involved in determining the sex of an individual.
The sex chromosomes are the X and Y chromosomes; females have two X chromosomes while males have one X and one Y chromosome.

Function of Chromosomes

Chromosomes play a crucial role in heredity, growth, repair, and reproduction.
They carry the genetic information in the form of genes.
Genes are specific sections of a chromosome and they dictate the physical features, traits and diseases an individual may have.

Role in Genetic Engineering

Knowledge of human chromosomes is vital for genetic engineering.
Genetic engineering can involve inserting, deleting, or replacing genes within an individual’s chromosomes.
This could result in solving genetic disorders or altering physical traits.

Understanding human chromosomes is the first step towards understanding inheritance, biological variation, and evolution. Knowledge of chromosomes underpins key aspects of genetic engineering, including cloning, gene therapy, and the production of genetically modified organisms (GMOs).