BIO Book 2: Organisation of Eukaryotic Genome

Definition of Genome

Genome is the genetic material of an organism or virus

It is the complete complement (entire set) of an organism’s or virus’s genes along with its non-coding nucleic acid sequences

Introduction

All organisms have a genome comprised of genetic material (DNA or RNA) that contains all the genetic information needed to direct the development and maintenance of that organism. The genome of an organism specifically refers to the entire complete set (or complement) of genetic information for all the proteins and RNA that the organism will ever synthesise.

Most genomes including the human genome and those of all other cellular life forms are made of DNA. Viruses may contain DNA or RNA genomes.

In prokaryotes:

• The genome resides usually in a single DNA molecule.

In eukaryotes:

• The typical eukaryotic genome is much larger

• Eukaryotic cells have a nuclear genome and also a mitochondrial genome, as well as a chloroplast genome in the case of plants and algae.

Definition of Gene

A gene is a section of the DNA that contains the information in the form of a specific sequence of nucleotides/bases to direct the synthesis of one polypeptide chain or RNA. It is a unit of inheritance located in a fixed position (locus) on the chromosome which specifies a particular character of an organism.

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