Structure of Bacteria

Iodine is used as a mordant in gram staining. It forms a coordination complex with dye and helps in binding of dye to the cell or tissue.

Pseudomonas aeruginosa is an obligate aerobe. It requires only free oxygen to survive.

Staphylococcus aureus divides in three planes in an irregular pattern, producing bunches of cocci.

Bacillus anthracis is a rod-shaped bacterium with spherical ends.

cGMP (cyclic guanine mono-phosphate) regulates the direction of rotation of flagella.

Eubacteria is a bacterium of a large group that typically has simple cells with rigid cell walls and flagella for movement.

The capsular polysaccharides are polymerised outside the cell wall.

Correct Answer: Pleuropneumonia-like organisms

Stalks are non-living ribbon-like or tubular appendages that are excreted outside the cell.

Bacterial DNA is double stranded and circular.

The anaerobic synthesis that is found in bacteria is endergonic. Endergonic means absorbing energy in the form of work. Endergonic reactions are not spontaneous. By thermodynamic standards, positive work, a form of energy, is defined as moving from the surroundings (the external region) to the system (the internal region). Thus, an endergonic process is one wherein the system absorbs energy from the surroundings. Anaerobic synthesis as found in bacteria is endergonic.

The capsule of Bacillus anthracis is entirely made up of D-glutamic acid. This amino acid is rare as most of the other capsules contain L form of amino acid.

The shape-determining part of a cell is the cell wall. It is made up of peptidoglycan, which is a polymer of NAG, NAM and DAPA.

In a gram stain test, L-forms always colour gram-negative due to the lack of a cell wall.

Thiomargarita namibiensis means sulphur pearl of Namibia. It is the largest bacterium in the world. It is visible to the naked eye as a speck of size 3 - 4 mm.