Nokea
The innate immune system provides a non-specific first line of defense. What are some physical barriers that contribute to the innate immune system?
- A. Antibodies
- B. Phagocytes
- C. Skin and mucous membranes
- D. Memory B cells
Correct Answer: C
Rationale: Physical barriers such as the skin and mucous membranes are crucial components of the innate immune system's first line of defense. These barriers act as physical obstacles that prevent pathogens from entering the body. Antibodies (option A) are produced by the adaptive immune system in response to specific pathogens and do not serve as physical barriers. Phagocytes (option B) are cells that engulf and digest pathogens, playing a role in the innate immune response but not as physical barriers. Memory B cells (option D) are part of the adaptive immune system and aid in mounting a faster and more effective immune response upon subsequent exposure to a specific pathogen, but they are not physical barriers against initial pathogen entry.
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What is the process by which cells respond to external stimuli, such as chemicals, temperature, or touch, called?
- A. Signal transduction
- B. Homeostasis
- C. Adaptation
- D. Metabolism
Correct Answer: A
Rationale: Signal transduction is the correct answer. It is the process by which cells respond to external stimuli like chemicals, temperature, or touch. When a cell receives a signal from its environment, it triggers a series of molecular events leading to a specific cellular response. This process involves transmitting signals from the cell surface to the interior, triggering various cellular activities. Homeostasis, on the other hand, refers to an organism's ability to maintain internal stability in response to external changes. Adaptation involves an organism adjusting to its environment over time through genetic changes or behavioral modifications, which is distinct from the process of cells responding to immediate external stimuli. Metabolism, although essential for cellular functions, is not specifically about cells responding to external stimuli but rather the biochemical processes involved in energy production, storage, and utilization within cells.
Which lobe of the brain is primarily responsible for processing visual information?
- A. Frontal lobe
- B. Parietal lobe
- C. Temporal lobe
- D. Occipital lobe
Correct Answer: D
Rationale: The occipital lobe, located at the back of the brain, is primarily responsible for processing visual information. It contains the primary visual cortex, which interprets visual stimuli received from the eyes. The frontal lobe is primarily involved in higher cognitive functions, the parietal lobe in sensory processing and spatial awareness, and the temporal lobe in auditory processing and memory. Therefore, choices A, B, and C are incorrect as they are associated with functions different from visual processing.
The tonsils and adenoids are part of the lymphatic system located in the:
- A. Chest cavity
- B. Abdominal cavity
- C. Head and neck region
- D. Pelvic cavity
Correct Answer: C
Rationale: The tonsils and adenoids are lymphatic tissues located in the head and neck region, specifically in the throat area. They are essential components of the immune system, acting as the first line of defense against infections that can enter through the nose and mouth. The tonsils are situated at the back of the throat, while the adenoids are positioned high in the throat behind the nose. Choices A, B, and D are incorrect as they do not correspond to the anatomical location of the tonsils and adenoids. Therefore, the correct answer is the head and neck region.
What is the difference between exhalation (expiration) and inhalation (inspiration)?
- A. Exhalation involves active muscle contraction, while inhalation is passive.
- B. Inhalation brings in oxygen-rich air, while exhalation releases carbon dioxide-rich air.
- C. Exhalation occurs through the nose only, while inhalation can occur through the nose or mouth.
- D. Inhalation warms and humidifies air, while exhalation cools and dries air.
Correct Answer: A
Rationale: Exhalation (expiration) involves active muscle contraction, specifically the diaphragm and intercostal muscles, to decrease the volume of the thoracic cavity and push air out of the lungs. In contrast, inhalation (inspiration) is a passive process where the diaphragm and external intercostal muscles contract to increase the thoracic cavity volume, allowing air to flow into the lungs. Choice B is incorrect as exhalation removes carbon dioxide-rich air and inhalation brings in oxygen-rich air. Choice C is incorrect because both exhalation and inhalation can occur through the nose or mouth. Choice D is inaccurate as inhalation humidifies and warms the air, while exhalation cools and dries it.
Which of the following statements about prions is TRUE?
- A. They are composed of proteins only
- B. They are easily destroyed by common disinfectants
- C. hey are a type of antibiotic
- D. They are a live organism
Correct Answer: A
Rationale: A) This statement is true. Prions are infectious agents composed entirely of protein, lacking nucleic acids such as DNA or RNA. They are known for causing neurodegenerative diseases in animals and humans.
B) This statement is false. Prions are not easily destroyed by common disinfectants due to their unique structure and resistance to conventional sterilization methods.
C) This statement is false. Prions are not a type of antibiotic. They are a distinct class of infectious agents.
D) This statement is false. Prions are not live organisms but rather misfolded proteins that can induce abnormal folding in normal proteins, leading to disease.