Question

Bacteriophage $\mathop T\nolimits_2$ is
A)Filamentous
B)Cuboidal
C)Binal
D)Spherical

Answer 1

A bacteriophage is defined as a virus that infects and replicates within bacteria. It is also termed to as the phage. It duplicates within the bacterium after injecting its genome into the bacterial cytoplasm. Examples of bacteriophages include: my phages, lambda phages, filamentous and spherical phages.

Complete answer:
Bacteriophages are made up of proteins which encapsulate the DNA or RNA genome. Morphologically, phages possess the nucleic acid that is covered in a proteinaceous capsid/coat which is made up of nucleoproteins.
It shows the presence of a head composed of protein, inner core of nucleic acid and a hollow protein tail.

The capsid of a bacteriophage can have icosahedral, filamentous or head-tail shape which is termed as the Binal symmetry. The head-tail structure is unique and very distinct to phages. However, it is present as a tadpole structure with DNA inside the proteinous head.
It connects itself to a bacterium and infects it. The bacteriophage then hijacks the bacterium's cellular machinery and also helps to prevent it from producing bacterial components and forces the cell to produce viral Phages and components instead. Therefore, new bacteriophages are developed and then burst out of the bacterium by a process called lysis. Bacteriophages destroy and damage the bacteria by lysis or dissolution.

Hence, the correct answer is option (C)

Note: The bacteriophages show presence of two different cycles to infect their bacterial hosts as follows:
The lytic cycle: The bacteriophage infects a bacterium, hijacks it to synthesise more phages and then at the spot kills the bacteria leading to the release of the bacteriophages produced.
The lysogenic cycle: The bacteriophage infects a bacterium and adds its DNA into the bacterial chromosome, allowing the phage DNA (prophage) to be replicated and duplicated further and passed on along with the cell's own DNA In the future generations.