Correct Answer: A

Rationale: The correct answer is A: Candidiasis. In infants, a thick white deposit on the oral mucosa and tongue is indicative of oral thrush, which is caused by the yeast fungus Candida. Infants are particularly susceptible to Candidiasis due to their developing immune systems and use of antibiotics. Favus (B) is a chronic fungal infection of the scalp caused by Trichophyton schoenleinii, typically not seen in infants. Epidermophytosis (C) refers to superficial fungal infections of the skin caused by dermatophytes, not commonly found in the oral cavity of infants. Actinomycosis (D) is a bacterial infection caused by Actinomyces species, not a fungal infection.

Correct Answer: A

Rationale: The correct answer is A: Β-lactamase. In ELISA, enzymes like alkaline phosphatase, horseradish peroxidase, and Β-galactosidase are commonly used as labels to detect the presence of specific molecules. Β-lactamase is not typically used in ELISA as it is an enzyme used to hydrolyze β-lactam antibiotics. Therefore, it does not serve the purpose of detecting specific molecules in ELISA. Alkaline phosphatase, horseradish peroxidase, and Β-galactosidase are preferred enzymes in ELISA due to their ability to produce a detectable signal when bound to specific molecules.

Correct Answer: B

Rationale: Decontamination is the reduction or removal of unwanted chemical or biological agents to make an area safe. This includes cleaning, disinfecting, or sterilizing to eliminate harmful substances. Choice A is incorrect as decontamination doesn't necessarily involve killing all microorganisms. Choice C is incorrect as it focuses on stopping growth, not removing existing contaminants. Choice D is incorrect as it specifically mentions vegetative organisms, which may not cover all types of contaminants that need to be removed during decontamination. Thus, the correct answer is B as it accurately describes the process of decontamination.

Correct Answer: A

Rationale: The correct answer is A: Logarithmic phase. During this phase, bacteria multiply exponentially due to abundant nutrients and favorable conditions. The growth is rapid and follows a geometric progression. In contrast, the Death phase (choice B) occurs when nutrients are depleted, leading to a decline in bacterial numbers. The Stationary phase (choice C) is when growth equals death rates, resulting in a stable population size. Choice D is incorrect because the Logarithmic phase accurately describes the exponential growth pattern of bacteria in artificial media.

Correct Answer: C

Rationale: The correct answer is C: peroxisomes. Peroxisomes contain enzymes involved in breaking down fatty acids and detoxifying harmful substances. They do not contain digestive enzymes. Lysosomes contain digestive enzymes involved in breaking down waste materials. Chloroplasts are involved in photosynthesis and do not contain digestive enzymes. Mitochondria are involved in energy production and do not contain digestive enzymes. Therefore, the correct answer is peroxisomes.