Growth of bacteria is a result of:

Correct Answer: B

Rationale: The growth of bacteria is a result of water adsorption because water is essential for various metabolic processes within the bacterial cells, such as nutrient uptake, energy production, and waste removal. Water serves as a medium for chemical reactions to occur and provides structural support to the bacteria. Without sufficient water, bacteria cannot thrive and reproduce. A: Air consumption is incorrect because while bacteria may require oxygen for respiration, it is not the primary factor for their growth. C: Enzyme production is incorrect because enzymes are important for various cellular functions but do not directly influence bacterial growth. D: Radio isotopes are incorrect as they are not essential for bacterial growth and can even be harmful to bacterial cells.

Correct Answer: A

Rationale: The correct answer is A because Gram-negative bacteria have a unique cell envelope structure consisting of a cytoplasmic membrane, a peptidoglycan layer, and an outer membrane. The cytoplasmic membrane is the innermost layer that separates the cytoplasm from the external environment. The peptidoglycan layer provides structural support to the cell. The outer membrane acts as an additional protective barrier and contains lipopolysaccharides. Choice B is incorrect because Gram-negative bacteria have an outer membrane in addition to the cytoplasmic membrane and peptidoglycan layer. Choice C is incorrect because Gram-negative bacteria have more than just a peptidoglycan layer in their cell envelope. Choice D is incorrect as the cell envelope of Gram-negative bacteria does have specific components.

Correct Answer: B

Rationale: The correct answer is B: Salmonella enteritidis. Salmonellosis is typically caused by Salmonella species, with Salmonella enteritidis being one of the common culprits. Salmonella typhi causes typhoid fever, not salmonellosis. Shigella flexneri is responsible for causing shigellosis, a different bacterial infection. Choosing "None of the above" is incorrect as Salmonella enteritidis is a known cause of salmonellosis.

Correct Answer: B

Rationale: Step-by-step rationale for why choice B (Tuberculin is introduced) is correct: 1. Tuberculin test helps identify individuals with latent TB infection. 2. Negative skin-allergic samples suggest absence of active TB. 3. Introducing tuberculin can help confirm latent TB infection. 4. Antibiotics are not prescribed for negative skin-allergic samples. 5. Vaccines are not administered for TB diagnosis. Summary: - Choice A is incorrect as antibiotics are not prescribed for negative skin-allergic samples. - Choice C is incorrect as vaccines are not used for TB diagnosis. - Choice D is incorrect as introducing tuberculin is the appropriate step in this scenario.

Correct Answer: C

Rationale: The correct answer is C: cytoplasmic membrane. The cytoplasmic membrane is the fluidlike portion of a cell that separates the cell's contents from the external environment. It regulates the passage of substances in and out of the cell, maintains cell shape, and provides protection. Rationale: 1. Cytosol (choice A) is the liquid component of the cytoplasm where organelles are suspended, not the fluidlike portion of the cell. 2. Nucleoplasm (choice B) refers to the liquid component of the nucleus, not the entire cell. 3. Inclusion (choice D) refers to non-living substances within the cell that are not considered the fluidlike portion. Summary: The cytoplasmic membrane is the correct answer as it encompasses the entire cell and is responsible for maintaining cell integrity and regulating transport. Choices A, B, and D are incorrect as they do not represent the fluidlike portion of the cell.