Nokea
Which structure in the ear is responsible for hearing?
- A. Cochlea
- B. Semicircular canals
- C. Ossicles
- D. Eustachian tube
Correct Answer: A
Rationale: The cochlea, located in the inner ear, is responsible for detecting sound waves and converting them into neural signals that are sent to the brain for processing. It plays a crucial role in the process of hearing by translating mechanical vibrations into electrical signals that the brain can interpret as sound. The semicircular canals (Choice B) are responsible for balance and detecting head movements, not hearing. The ossicles (Choice C) are three tiny bones in the middle ear that transmit sound vibrations from the eardrum to the cochlea. The Eustachian tube (Choice D) helps equalize pressure between the middle ear and the atmosphere, but it is not directly involved in the process of hearing.
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What is the primary role of the small intestine in nutrient absorption?
- A. To break down food
- B. To absorb nutrients
- C. To secrete digestive enzymes
- D. To store glucose
Correct Answer: B
Rationale: The correct answer is B: 'To absorb nutrients.' The small intestine is the primary site for nutrient absorption in the digestive system. It plays a crucial role in absorbing nutrients from digested food into the bloodstream, facilitating the delivery of essential nutrients to the body for various functions and processes. Choices A, C, and D are incorrect because while the small intestine does contribute to the breakdown of food and does secrete digestive enzymes, its primary function is to absorb nutrients, not to store glucose.
Which of the following is not part of the central nervous system?
- A. Retina
- B. Spinal cord
- C. Brain
- D. Heart
Correct Answer: B
Rationale: The central nervous system consists of the brain and spinal cord, which are responsible for processing and coordinating information. The retina is part of the eye, while the heart is part of the circulatory system. Therefore, the correct answer is 'Spinal cord' as it is not part of the central nervous system.
Which organelle in the cell contains the genetic material?
- A. Ribosome
- B. Nucleus
- C. Mitochondria
- D. Endoplasmic reticulum
Correct Answer: B
Rationale: The correct answer is B, Nucleus. The nucleus is the organelle in the cell that contains the genetic material (DNA). DNA within the nucleus determines the cell's functions and characteristics, making it essential for cell function and replication. Choice A, Ribosome, is responsible for protein synthesis, not genetic material storage. Choice C, Mitochondria, produces energy but does not contain the genetic material. Choice D, Endoplasmic reticulum, is involved in protein synthesis and lipid metabolism but does not house the genetic material.
Which of the following endocrine system glands releases the thyrotrophic-releasing hormone, growth hormone-releasing hormone, and gonadotropin-releasing hormones?
- A. Thymus
- B. Pituitary gland
- C. Pineal gland
- D. Hypothalamus
Correct Answer: D
Rationale: The correct answer is D, the Hypothalamus. The hypothalamus is responsible for releasing various essential hormones, including thyrotrophic-releasing hormone, growth hormone-releasing hormone, and gonadotropin-releasing hormones. These hormones play crucial roles in regulating the functions of other endocrine glands by stimulating or inhibiting their hormone production. The Thymus (choice A) is primarily involved in the immune system, the Pituitary gland (choice B) secretes various hormones but not the ones specified in the question, and the Pineal gland (choice C) mainly produces melatonin, which regulates sleep-wake cycles, and is not related to the hormones mentioned in the question.
Which part of the brain controls breathing and heart rate?
- A. Cerebrum
- B. Medulla oblongata
- C. Cerebellum
- D. Hypothalamus
Correct Answer: B
Rationale: The medulla oblongata, located in the brainstem, plays a crucial role in controlling vital functions such as breathing, heart rate, and blood pressure. It serves as the control center for automatic functions necessary for survival, making it the correct choice in this scenario. The cerebrum is responsible for higher brain functions like thinking and voluntary movements, so it does not control basic physiological functions like breathing and heart rate. The cerebellum is mainly involved in coordination and balance, while the hypothalamus regulates body temperature, hunger, and thirst, but not specifically breathing and heart rate.