The only way to get energy in haematrophic bacteria is:

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: C

Rationale: The correct answer is C: High amount of mycolic acids. Mycobacteria are characterized by their unique cell wall composition, which includes a high amount of mycolic acids. Mycolic acids provide the bacteria with resistance to environmental stresses and are crucial for their pathogenicity. Polysaccharides (A) are not a prominent component of mycobacterial cell walls. While lipids (B) are present in mycobacterial cell walls, mycolic acids are the predominant lipid. Proteins (D) are also present but are not the defining feature of mycobacterial cell walls. Therefore, the correct answer is C due to the significant role mycolic acids play in the structure and function of mycobacterial cell walls.

Correct Answer: B

Rationale: The correct answer is B: Mycelium. Mycelium refers to the network of branching filaments that form the main body of a fungus. When fungi grow on solid media, they develop a visible mass of mycelium. Hyphae (A) are the individual filaments that make up mycelium. Spores (C) are reproductive cells produced by fungi. Columella (D) refers to a specialized structure found in some fungi but is not related to the colonies grown on solid media. Therefore, the correct term for the colonies of fungi on solid media is mycelium.

Correct Answer: D

Rationale: The correct answer is D: Altered penicillin binding proteins. MRSA (Methicillin-resistant Staphylococcus aureus) achieves resistance to beta-lactam antibiotics, such as penicillin, by producing altered penicillin binding proteins that have reduced affinity for these antibiotics. This alteration prevents the antibiotics from binding to their target sites on the bacterial cell wall, thus rendering them ineffective. Choice A, extended spectrum beta-lactamases, are enzymes produced by some bacteria to break down beta-lactam antibiotics, but MRSA does not use this mechanism. Choice B, penicillin efflux pump, is a mechanism where bacteria pump out antibiotics from their cells, but this is not how MRSA develops resistance. Choice C, altered peptide sequence in peptidoglycan, does not directly relate to how MRSA resists beta-lactam antibiotics.

Correct Answer: B

Rationale: The correct answer is B because the term "infectious process" refers to all biological processes that occur after the attachment and penetration of microbes into the host organism, regardless of whether there are clinical manifestations. This includes the colonization, multiplication, and spread of the microorganisms within the host. Explanation: A: Incorrect because it only mentions the attachment and penetration of microbes into the microorganism, missing the subsequent processes. C: Incorrect because it is too specific, stating that the penetration of microbes always manifests clinically, which is not always the case. D: Incorrect because there is a correct answer, which is B, as explained above.