Which of the following statements regarding macrophages is incorrect?
- A. They are found abundantly in the blood
- B. They are larger than neutrophils
- C. They are long-lived
- D. They are made in the bone marrow as monocytes, called macrophages once they reach organs
Correct Answer: A
Rationale: The correct answer is A. Macrophages are not found abundantly in the blood; they are present in tissues and organs. Macrophages are tissue-resident immune cells that play a key role in immune responses and are derived from monocytes produced in the bone marrow. Choice B is correct as macrophages are larger than neutrophils. Choice C is correct as macrophages are long-lived cells. Choice D is correct as macrophages originate in the bone marrow as monocytes and differentiate into macrophages once they migrate to various tissues and organs.
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What is the end product of glycolysis?
- A. Lactic acid
- B. ATP
- C. NADPH
- D. Pyruvic acid
Correct Answer: D
Rationale: The correct answer is D: Pyruvic acid. The end product of glycolysis is pyruvic acid, not lactic acid, ATP, or NADPH. Pyruvic acid is a key intermediary in cellular respiration and can be further metabolized to produce energy through processes like the citric acid cycle and oxidative phosphorylation. Lactic acid is produced in the absence of oxygen during fermentation, ATP is a product of cellular respiration but not the direct end product of glycolysis, and NADPH is generated in other metabolic pathways such as the pentose phosphate pathway, not in glycolysis.
What is the primary function of the kidneys?
- A. To digest food
- B. To filter blood and produce urine
- C. To absorb nutrients
- D. To transport oxygen
Correct Answer: B
Rationale: The primary function of the kidneys is to filter blood and remove waste products from the body, producing urine in the process. This function helps in maintaining the body's internal environment stable, a process known as homeostasis. Option A, 'To digest food,' is incorrect as digestion primarily occurs in the gastrointestinal system, not in the kidneys. Option C, 'To absorb nutrients,' is also incorrect because nutrient absorption mainly takes place in the intestines. Option D, 'To transport oxygen,' is incorrect as the lungs and circulatory system are responsible for oxygen transport, not the kidneys.
Which of the following glands is responsible for regulating metabolism?
- A. Thymus
- B. Pituitary
- C. Pancreas
- D. Thyroid
Correct Answer: D
Rationale: The correct answer is D, Thyroid. The thyroid gland is responsible for regulating metabolism by producing thyroid hormones. These hormones play a crucial role in controlling various metabolic processes in the body, including energy production and utilization. Choice A, Thymus, is not responsible for regulating metabolism but plays a role in the immune system. Choice B, Pituitary, regulates various hormones but not specifically focused on metabolism. Choice C, Pancreas, is involved in insulin production and blood sugar regulation but is not primarily responsible for regulating metabolism.
Which structure in the body is responsible for detecting light and converting it into signals for the brain?
- A. Iris
- B. Retina
- C. Lens
- D. Pupil
Correct Answer: B
Rationale: The correct answer is the Retina. The retina in the eye contains specialized cells called photoreceptors that detect light and convert it into neural signals. These signals are then transmitted to the brain via the optic nerve for visual processing. The iris is responsible for controlling the amount of light entering the eye by adjusting the size of the pupil, while the lens helps focus light onto the retina. The pupil is simply the opening in the center of the iris that allows light to enter the eye.
Which of the following lobes of the brain is responsible for sensation, perception, and spatial reasoning?
- A. Frontal
- B. Occipital
- C. Parietal
- D. Temporal
Correct Answer: C
Rationale: The parietal lobe is responsible for sensation, perception, and spatial reasoning. It plays a crucial role in processing sensory information, assisting in spatial orientation, and integrating various sensory inputs to create a comprehensive perception of the surrounding environment. The frontal lobe, although important for higher cognitive functions and motor skills, is not primarily responsible for sensation, perception, or spatial reasoning. The occipital lobe is mainly involved in visual processing, and the temporal lobe is primarily associated with auditory processing, memory, and emotions, making them incorrect choices for this question.