How do the genome sizes of T2 phage, Escherichia coli, Drosophila melanogaster, Homo sapiens, and Paris japonica compare?

Sourav PanNovember 8, 2024

Answered

The genome sizes of T2 phage, Escherichia coli, Drosophila melanogaster, Homo sapiens, and Paris japonica vary significantly, reflecting the diversity of organisms and their genetic complexity. Here’s a comparison of their genome sizes based on the available information:

Genome Size Comparison

Details of Each Organism

1. T2 Phage:
   • The T2 phage, a bacteriophage that infects E. coli, has a relatively small genome size of approximately 163,826 base pairs. This compact genome encodes the necessary information for the phage’s life cycle and replication within its bacterial host.
2. Escherichia coli:
   • The genome of E. coli typically ranges from about 4.6 to 5.0 million base pairs (4.6 to 5.0 Mb), depending on the strain. This size allows for the encoding of around 4,200 to 5,000 genes, which are essential for its metabolic functions and adaptability.
3. Drosophila melanogaster:
   • The fruit fly (Drosophila melanogaster) has a genome size of approximately 175 million base pairs (175 Mb). This organism is widely used in genetic research due to its relatively simple genetics and short generation time.
4. Homo sapiens:
   • The human genome is approximately 3.2 billion base pairs (3,200 Mb). It contains about 20,000 to 25,000 protein-coding genes and a vast amount of non-coding DNA that plays roles in regulation and other functions.
5. Paris japonica:
   • The plant Paris japonica holds the record for the largest known genome at around 150 billion base pairs (150 Gb). This enormous size is attributed to its high degree of polyploidy and repetitive sequences.