Q.Describe the structure of a T-even bacteriophage.

[!TLDR]

The question asks for a description of the structure of a T-even bacteriophage. …

T-even bacteriophages, the group that includes T2, T4 and T6 (all of which infect the bacterium Escherichia coli), show one of the most elaborate structures among viruses, described as having complex symmetry because different parts of the particle are built on different geometric patterns. At one end is a polyhedral (icosahedral) head, a many-faced, roughly spherical structure that tightly encloses the phage's genetic material - double-stranded DNA. This head is connected to a cylindrical tail, which is itself made up of several distinct parts: a tail sheath surrounding a central tail tube running down its length, a base plate at the far end of the tail, and a set of thin tail fibres projecting outward from the base plate. The tail fibres are responsible for recognising and attaching to specific receptor sites on the surface of the host bacterium, after which the tail …

• Describing the phage as having only a single, uniform shape rather than distinguishing its polyhedral head from its separately structured tail. …