The Human Genome

Human Genome Basics

• The main function of the human genome is to provide the genetic instructions for the development and function of an organism.

Nuclear DNA

• Somatic cells contain 2 molecules of nuclear DNA.
• Sex cells, on the other hand, contain 1 molecule of nuclear DNA.
• The 46 DNA molecules in somatic cells contain approximately 20,000-25,000 genes.

Mitochondrial DNA

• The number of mitochondrial DNA molecules varies between cells due to the process of mitochondrial replication, which occurs independently of nuclear DNA replication.
• Mitochondrial DNA is responsible for generating energy for the cell through cellular respiration.

Karyotype

• The human karyotype consists of 23 different chromosome pairs, for a total of 46 chromosomes.
• The function of the karyotype is to provide a complete picture of an individual's chromosomes, allowing for the identification of chromosomal abnormalities.
• In contrast to the karyotype, the plasmotype refers to the complete set of genetic material found in plasmids, which are small, circular DNA molecules found in bacteria.

Key Distinctions

• The main difference between the karyotype and the plasmotype is the source of the genetic material: the karyotype is found in the nucleus of eukaryotic cells, while the plasmotype is found in prokaryotic cells.