The cell organelle responsible for the packaging of proteins is the:

Correct Answer: B

Rationale: The correct answer is B: ribosome. Ribosomes are responsible for protein synthesis, not packaging. The Golgi complex (A) processes and packages proteins. The rough endoplasmic reticulum (rER) (C) is involved in protein synthesis and transport. Lysosomes (D) contain enzymes for digestion, not protein packaging. Therefore, ribosomes are the organelle directly involved in protein synthesis, making it the correct choice.

Correct Answer: A

Rationale: The correct answer is A: Hemolytic streptococci. Hemolytic streptococci are pathogenic bacteria that can cause severe infections in humans, indicating direct epidemiological danger. Hemolytic streptococci are commonly found in the respiratory tract and can be transmitted through the air, making them a good indicator of pathogenic microorganisms in the air. Summary: - B: Sarcina, molds, yeast, and Micrococci are not typically indicators of direct epidemiological danger related to pathogenic microorganisms in the air. - Hemolytic streptococci, on the other hand, are pathogenic bacteria that can cause serious infections and are commonly transmitted through the air, making them a suitable indicator in this context.

Correct Answer: D

Rationale: The correct answer is D: Cytoplasmic membrane - essential. The cytoplasmic membrane is a crucial structure in bacteria as it regulates the passage of substances in and out of the cell, provides structural support, and is essential for maintaining cell integrity. Without a functional cytoplasmic membrane, bacteria would not be able to survive. A: Nucleus is incorrect because bacteria do not have a true nucleus. B: Capsule - non-essential is incorrect because while the capsule provides protection and helps in adherence, it is not essential for bacterial survival. C: Mitochondria is incorrect because bacteria do not have mitochondria; they generate energy through other mechanisms. In summary, the cytoplasmic membrane is essential for bacterial survival, making it the correct choice among the options provided.

Correct Answer: B

Rationale: The correct answer is B: Gamma globulin, as it is not a primary immunodeficiency disease. Primary immunodeficiency diseases are genetic disorders that affect the immune system's ability to fight infections. A: Glanzmann-Riniker hypergammaglobulinemia is a rare primary immunodeficiency characterized by elevated levels of gammaglobulins. C: Variable hypogammaglobulinemia is a primary immunodeficiency disease where there are fluctuating levels of gammaglobulins. D: Bruton hypogammaglobulinemia, also known as X-linked agammaglobulinemia, is a primary immunodeficiency characterized by a lack of B cells and gammaglobulins. In summary, B is the correct answer as gamma globulin is not a primary immunodeficiency disease, whereas A, C, and D are all examples of primary immunodeficiency diseases affecting gammaglobulins levels.

Correct Answer: B

Rationale: The correct answer is B: Family Reoviridae. Reassortment of gene segments occurs in segmented viruses like Reoviruses. In Reoviridae, each segment encodes a specific protein, allowing for reassortment to generate new strains. Togaviridae (A) is a non-segmented virus, not capable of reassortment. Picornaviridae (C) and Paramyxoviruses (D) are also non-segmented viruses, limiting their ability for reassortment. Therefore, the correct choice is B due to the segmented nature of Reoviruses allowing for genetic reassortment.

Correct Answer: A

Rationale: The correct answer is A: Candida. The whitish spots resembling coagulated milk on the mucous membranes are characteristic of oral thrush, a condition caused by Candida species. Candida is a gram-positive oval yeast-like fungus commonly found in the oral cavity. Staphylococci (B) are gram-positive cocci, not yeast-like cells. Diphtheria bacillus (C) causes diphtheria, not oral thrush. Actinomycetes (D) are filamentous bacteria, not yeast-like cells typically seen in oral thrush. Therefore, A is the correct answer based on the clinical presentation and microscopic findings.

Correct Answer: D

Rationale: The correct answer is D because utilizing all three methods—immunofluorescence, viral neutralization reaction, and electron microscopy—provides a comprehensive and rapid diagnosis of various viral infections. Immunofluorescence detects viral antigens directly, viral neutralization reaction demonstrates the presence of specific antibodies, and electron microscopy visualizes viral particles. This combination ensures accurate and quick identification of different viruses. Choices A, B, and C alone may not cover all aspects of viral diagnosis, making them less effective compared to the comprehensive approach of using all three methods.

Correct Answer: C

Rationale: The correct answer is C: after repeated exposure for days. Subacute toxic effects typically manifest after a period of time that is longer than immediate (A) or acute (B) effects but shorter than chronic effects (D). This duration of days aligns with the definition of subacute, which refers to effects that occur gradually over a relatively short time frame. It is important to differentiate between the timing of toxic effects to accurately assess the potential harm caused by a substance. Choices A, B, and D are incorrect because they do not align with the characteristic time frame associated with subacute toxic effects.

Correct Answer: A

Rationale: The correct answer is A: Metronidazole. Amebic dysentery is caused by the parasite Entamoeba histolytica, not bacteria. Metronidazole is the drug of choice for treating this parasitic infection. It works by disrupting the DNA structure of the parasite, leading to its death. Mebendazole (B) is used to treat certain worm infections, not amebic dysentery. Itrakonazole (C) is an antifungal medication and not effective against parasites. Furacillin (D) is an antibacterial agent and not suitable for treating parasitic infections like amebic dysentery.