Nokea
What are substances that stimulate adaptive immunity called?
- A. Peptides
- B. Phagocytes
- C. Prions
- D. Platelets
Correct Answer: A
Rationale: Substances that stimulate adaptive immunity are called peptides. Peptides are short chains of amino acids that play a crucial role in activating the immune response by interacting with immune cells such as T cells and B cells. Peptides are important in antigen presentation and recognition, leading to the development of specific immune responses against pathogens. Choice B, phagocytes, are cells that engulf and digest pathogens but are not substances that stimulate adaptive immunity. Choice C, prions, are infectious agents made of misfolded proteins and are not related to stimulating adaptive immunity. Choice D, platelets, are cell fragments involved in blood clotting and have no direct role in stimulating adaptive immunity.
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Which of the following organs does not belong with the others?
- A. Thyroid gland
- B. Stomach
- C. Intestines
- D. Pancreas
Correct Answer: B
Rationale: The correct answer is B - Stomach. The stomach is primarily involved in the digestive system, breaking down food through digestion. In contrast, the thyroid gland, intestines, and pancreas are part of the endocrine system or digestive system, involved in hormone production, nutrient absorption, and digestion. Therefore, the stomach stands out as the odd one in this group as it is the only organ specifically dedicated to digestion, while the others have dual roles or different primary functions.
Which of the following statements best defines an organelle?
- A. Layer of polysaccharides outside the plasma membrane of cells.
- B. Abnormal infectious proteins.
- C. Specialized structures within a cell.
- D. Collection of tissues used to serve a specific function.
Correct Answer: C
Rationale: The correct answer is C: 'Specialized structures within a cell.' An organelle is a specialized subunit within a cell that has a specific function. Organelles are membrane-bound structures found within the cytoplasm of eukaryotic cells, each performing distinct roles that contribute to the overall functioning of the cell. Choices A, B, and D are incorrect. Option A describes the glycocalyx, which is a layer of polysaccharides outside the plasma membrane of cells. Option B refers to prions, abnormal infectious proteins. Option D defines an organ, a collection of tissues used to serve a specific function, rather than an organelle within a cell.
Which of the following anatomical terms is not part of the knee?
- A. Medial collateral ligament
- B. Patella
- C. Lateral malleolus
- D. Lateral meniscus
Correct Answer: C
Rationale: The lateral malleolus is a bony prominence on the lateral side of the ankle and is not part of the knee anatomy. The other options - medial collateral ligament, patella, and lateral meniscus - are all structures within the knee joint. The medial collateral ligament is located on the inner side of the knee, the patella is the kneecap, and the lateral meniscus is a cartilage structure within the knee joint. Therefore, the correct answer is C, lateral malleolus.
When a certain plant is introduced into an area, and the population of a certain insect species declines, what can be concluded from this?
- A. The plant is toxic to the insect in question.
- B. The plant competes with and drives out plants that the insect feeds on.
- C. The insect population was declining anyway; the fact that it happened when the plant was introduced is a coincidence.
- D. All of these explanations may be possible; further investigation is necessary to determine which is true.
Correct Answer: D
Rationale: The given scenario presents multiple possible explanations for the decline in the insect population with the introduction of a particular plant. It could be due to the plant being toxic to the insect (Option A), competing with and driving out plants that the insect feeds on (Option B), or the decline could be coincidental with the plant introduction as the insect population was already decreasing (Option C). Without further investigation and evidence, it is not possible to definitively determine which explanation is correct. Therefore, all of these possibilities may be true, and thorough investigation is necessary to reach a conclusive conclusion.
In the human skeleton, which of the following lists some of the vertebrae in descending order?
- A. Atlas, axis, thoracic, lumbar, sacral, coccyx.
- B. Axis, sacral, coccyx, atlas, lumbar, thoracic.
- C. Thoracic, sacral, lumbar, axis, coccyx, atlas.
- D. Coccyx, lumbar, axis, sacral, thoracic, atlas.
Correct Answer: A
Rationale: The correct order of some of the vertebrae in the human skeleton in descending order is Atlas, Axis, Thoracic, Lumbar, Sacral, Coccyx. This sequence follows the typical arrangement from the top of the spine down towards the pelvis. Choice B is incorrect as it does not follow the descending order of vertebrae. Choice C is incorrect as it starts with Thoracic which is not the first vertebra in the descending order. Choice D is incorrect as it starts with Coccyx which is the last vertebra in the descending order.