For family Togaviridae is true that

Correct Answer: C

Rationale: Step 1: Togaviridae is a family of viruses known to have non-segmented (+)ssRNA as their genetic material. Step 2: The positive sense RNA means that the viral RNA can be directly translated into proteins by host machinery. Step 3: This RNA genome acts as mRNA, allowing for immediate translation of viral proteins. Step 4: Therefore, choice C is correct as it accurately describes the genetic nature of Togaviridae. Summary: - Choice A is incorrect because Togaviridae viruses do not have helical symmetry. - Choice B is incorrect because Togaviridae viruses do not have non-segmented (-)dsRNA. - Choice D is incorrect because Togaviridae viruses are enveloped viruses.

Correct Answer: B

Rationale: The correct answer is B: Helicobacter pylori. This bacterium is associated with stomach ulcers as it can survive in the acidic environment of the stomach and produce substances that weaken the stomach lining. Escherichia coli (A) is associated with foodborne illnesses, not ulcers. Bacillus cereus (C) causes food poisoning. Clostridium difficile (D) is associated with antibiotic-associated colitis, not ulcers. Therefore, Helicobacter pylori is the correct answer based on its specific association with stomach ulcers.

Correct Answer: B

Rationale: The correct answer is B: Mycobacterium leprae. This bacterium is responsible for causing leprosy, also known as Hansen's disease. Mycobacterium leprae specifically targets the skin, peripheral nerves, and mucosa of the upper respiratory tract. It is an acid-fast bacterium with a slow growth rate, making it difficult to culture in the laboratory. Streptococcus pyogenes (choice A) is responsible for various infections such as strep throat, Neisseria gonorrhoeae (choice C) causes gonorrhea, and Escherichia coli (choice D) is commonly found in the gut and can lead to various infections but not leprosy.

Correct Answer: A

Rationale: The correct answer is A: Isoniazid. Isoniazid is known to cause peripheral neuropathy as a side effect, especially with prolonged use. It can lead to symptoms such as numbness, tingling, and weakness in the toes and fingers due to its neurotoxic effects. Rifampicin (B) is less likely to cause neuropathy. Ciprofloxacin (C) is not typically associated with neuropathy. Sodium salt of benzylpenicillin (D) is an antibiotic but is not known to cause polyneuritis.

Correct Answer: D

Rationale: The correct answer is D (All of the above) because all three bacteria (Clostridium botulinum, Escherichia coli, Salmonella enterica) are known to cause foodborne infections. Clostridium botulinum can lead to botulism, E. coli can cause various gastrointestinal illnesses, and Salmonella enterica is a common cause of food poisoning. Each bacterium has specific mechanisms that result in foodborne illnesses. Choices A, B, and C are incorrect because each bacterium mentioned is associated with causing foodborne infections, making them collectively the correct answer.

Correct Answer: C

Rationale: Step 1: Togaviridae is a family of viruses known to have non-segmented (+)ssRNA as their genetic material. Step 2: The positive sense RNA means that the viral RNA can be directly translated into proteins by host machinery. Step 3: This RNA genome acts as mRNA, allowing for immediate translation of viral proteins. Step 4: Therefore, choice C is correct as it accurately describes the genetic nature of Togaviridae. Summary: - Choice A is incorrect because Togaviridae viruses do not have helical symmetry. - Choice B is incorrect because Togaviridae viruses do not have non-segmented (-)dsRNA. - Choice D is incorrect because Togaviridae viruses are enveloped viruses.

Correct Answer: A

Rationale: The correct answer is A: TRUE. Poxviruses are indeed DNA viruses that replicate in the cytoplasm. This is due to their complex structure that allows them to carry out their replication process in the cytoplasm of the host cell. Other choices are incorrect because poxviruses specifically replicate in the cytoplasm and do not require the nucleus for replication, ruling out choice B. Choice C is incorrect because poxviruses consistently replicate in the cytoplasm regardless of the situation. Choice D is incorrect as the correct answer is A.

Correct Answer: A

Rationale: Ionizing radiation has enough energy to remove tightly bound electrons from atoms, creating charged particles (ions). UV light does not have enough energy to ionize atoms, making choice A the correct answer. Gamma rays, electron beams, and X-rays all have sufficient energy to cause ionization. Gamma rays are very high-energy electromagnetic radiation, electron beams are streams of high-energy electrons, and X-rays are high-energy electromagnetic radiation as well.

Correct Answer: B

Rationale: The correct answer is B: EIEC. This strain of E. coli can cause bloody diarrhea in children similar to shigellosis due to its ability to invade and replicate within the intestinal epithelial cells, leading to inflammation and bloody stools. ETEC (A) causes watery diarrhea due to enterotoxins. EAEC (C) causes persistent diarrhea. EPEC (D) causes attaching and effacing lesions on the intestinal mucosa without invasion.