Botany - 2

A typical virus consists of genetic material (DNA or RNA) enclosed in a protein coat (capsid). A mesh coil is not a biological component of a virus.

Bacteriophages, or simply phages, are viruses that infect and replicate within bacteria.

Chicken pox, the common cold, and AIDS are all caused by different types of viruses.

Chicken pox is a highly contagious disease caused by the varicella-zoster virus (VZV). Other options like Dengue, Rhino, and Corona viruses cause different illnesses such as dengue fever, the common cold, and COVID-19, respectively.

Viruses are generally larger than viroids. Viroids are the smallest known infectious agents, consisting only of a short strand of circular, single-stranded RNA without a protein coat, whereas viruses have a protein capsid and often a larger genome.

Potato spindle tuber disease is a classic example of a disease caused by a viroid. Cholera is caused by bacteria, and tobacco mosaic disease is caused by a virus.

Bacteria are classified by shape: rod-shaped bacteria are called bacilli (singular: bacillus), spherical bacteria are cocci, and spiral-shaped bacteria are spirilli.

Viroids are infectious agents composed solely of a short, circular, single-stranded RNA molecule, which is a low molecular weight nucleic acid. They lack the protein coat found in viruses.

Bunchy top of banana, potato leaf roll, and tobacco mosaic disease are all well-documented viral diseases that affect plants. Therefore, all of the listed options are correct.

Spherical bacteria are scientifically referred to as cocci (singular: coccus).

Comma-shaped bacteria are classified as Vibrio. This shape is distinct from the spherical cocci, rod-shaped bacilli, and spiral-shaped spirilli.

Staphylococci are spherical bacteria that divide in multiple planes to form irregular, grape-like clusters. Streptococci form chains, and diplococci form pairs.

The protein shell that encloses the genetic material of a virus is called a capsid. It is composed of smaller protein subunits known as capsomeres.

Fimbriae, pili, and flagella are all surface appendages found on various bacteria. They serve different functions such as attachment, conjugation, and motility.

The capsid of a virus is made up of repeating protein subunits called capsomeres. These subunits assemble to form the protective shell around the viral genome.

Bacterial flagella are primarily composed of a protein called flagellin. This protein polymerizes to form the helical filament that rotates to propel the bacterium.

Amphitrichous bacteria have a single flagellum or a tuft of flagella at both ends of the cell. This allows for movement in either direction.

Peritrichous bacteria have flagella distributed over the entire surface of the cell. This arrangement allows for efficient movement in various environments.

Atrichous bacteria are defined by the complete absence of flagella. They are generally non-motile.

The Gram staining method was developed by Hans Christian Gram in 1884. Since 'Christian Bern' is not the correct name, 'None of these' is the correct choice.

Lophotrichous bacteria have a tuft of flagella at one end of the cell. This arrangement helps the bacteria move rapidly through their environment.

The bacterial cell wall is primarily composed of peptidoglycan, which is also known as mucopeptide or murein. This structure provides rigidity and protection to the cell.

Flagella are the primary organelles used by bacteria for locomotion. They act like propellers to move the cell through liquid media.

Prokaryotic cells, including bacteria, contain 70S ribosomes. These are smaller than the 80S ribosomes found in eukaryotic cells.

Pili (specifically sex pili) are specialized surface appendages that facilitate the transfer of genetic material between bacteria during the process of conjugation.