Correct Answer: B

Rationale: The correct answer is B: streptococci. This term refers to beadlike chains of cocci formed after cell division along a single axis. "Diplococci" (
A) are pairs of cocci, "tetrads" (
C) are groups of four cocci, and "sarcinae" (
D) are cube-like groups of eight cocci. Streptococci is the most appropriate term for describing the specific arrangement mentioned in the question.

Correct Answer: A

Rationale: The correct answer is A because in the lytic cycle, the bacteriophage destroys the host cell upon release, whereas in the lysogenic cycle, the phage integrates its DNA into the host genome without killing the host immediately. This integration may lead to the destruction of the host cell at a later stage.
Choice B is incorrect as lytic phages do destroy the host cell.
Choice C is incorrect as the two cycles have distinct mechanisms.
Choice D is incorrect as there are clear differences between the lytic and lysogenic cycles.

Correct Answer: C

Rationale:
Rationale:
Choice C is correct because Staphylococcus epidermidis, Escherichia coli, and Enterococcus spp. are common causative agents of nosocomial infections due to their presence on the skin, in the gut, and in healthcare settings. S. aureus and L. monocytogenes (
Choice
A) are also important pathogens but are less common in nosocomial infections. Enterobacteriaceae (
Choice
B) are a large family of bacteria that can cause infections but are not as commonly associated with nosocomial infections compared to the organisms in
Choice C. The correct answer (
Choice
C) encompasses pathogens commonly found in healthcare settings, making it the most suitable option.

Correct Answer: B

Rationale: The correct answer is B: Biological oxidation. Haematrophic bacteria obtain energy through biological oxidation, where they break down organic compounds to generate ATP for cellular processes. This process involves the transfer of electrons from the substrate to an electron transport chain to produce energy. Heat production (
A) is a byproduct of metabolism, not the primary way to obtain energy. In biosynthetic reactions (
C), energy is utilized rather than generated. Cultivation in culture media (
D) is a method of growing bacteria but does not directly provide energy.
Therefore, the correct answer is B as it aligns with the metabolic process of haematrophic bacteria.

Correct Answer: B

Rationale: The correct answer is B: protomeres. Viral capsomeres are the building blocks of viral capsids, which are protein coats that enclose and protect the viral genetic material. These capsomeres are made up of smaller subunits called protomeres. Envelopes (
A) refer to a lipid membrane surrounding some viruses, not the subunits of capsomeres. Capsids (
C) are the protein coats that capsomeres make up, not the subunits themselves. Nucleoids (
D) are found in bacterial cells and refer to the region where the genetic material is located, not the subunits of viral capsomeres.