Nokea
Which of the following statements is true about Noble gases?
- A. They are non-reactive.
- B. They are highly reactive.
- C. They have 8 valence electrons.
- D. They have 7 valence electrons.
Correct Answer: A
Rationale: The correct answer is A: Noble gases are non-reactive because they have a full valence shell with 8 electrons, making them stable and unlikely to form chemical bonds with other elements. Choice B is incorrect because Noble gases are known for their inertness and lack of reactivity. Choice C is incorrect because Noble gases have 8 valence electrons, which is a key characteristic that contributes to their stability. Choice D is incorrect because Noble gases have 8 valence electrons, not 7.
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Which of the following conditions is characterized by a high percentage of CO2 and a very low percentage of O2 in the blood?
- A. Asphyxia
- B. Emphysema
- C. Eupnea
- D. Hypoxia
Correct Answer: A
Rationale: Asphyxia is the correct answer as it refers to a condition with high CO2 and low O2 levels in the blood. Asphyxia can result in oxygen deprivation and excess carbon dioxide in the bloodstream, posing a life-threatening situation if not treated promptly. Emphysema is a chronic lung disease characterized by the damage to the air sacs in the lungs, leading to breathing difficulties. Eupnea denotes normal breathing without any abnormalities. Hypoxia, on the other hand, involves low oxygen levels reaching the body's tissues, which can result from various causes such as reduced oxygen in the air or respiratory issues.
What is the role of the diaphragm in the respiratory system?
- A. To regulate blood pressure
- B. To contract and expand the lungs
- C. To produce red blood cells
- D. To absorb oxygen
Correct Answer: B
Rationale: The correct answer is B: To contract and expand the lungs. The diaphragm plays a crucial role in the respiratory system by contracting and expanding the lungs. When it contracts, it flattens, increasing the volume of the thoracic cavity and causing air to be drawn into the lungs. Conversely, when it relaxes, it moves back up, decreasing the thoracic cavity volume and pushing air out of the lungs. This process is essential for breathing and the exchange of oxygen and carbon dioxide in the body. Choices A, C, and D are incorrect. The diaphragm is not involved in regulating blood pressure, producing red blood cells, or absorbing oxygen. Its primary function is to aid in respiration by facilitating breathing through its contraction and relaxation movements.
Which organ system is primarily responsible for transporting nutrients throughout the body?
- A. Respiratory
- B. Digestive
- C. Circulatory
- D. Nervous
Correct Answer: C
Rationale: The circulatory system, also known as the cardiovascular system, is primarily responsible for transporting nutrients and oxygen throughout the body. The heart pumps blood through blood vessels, delivering essential nutrients to cells and tissues. This system consists of the heart, blood vessels, and blood, working together to ensure the proper distribution of nutrients and removal of waste products. Choice A, the respiratory system, is responsible for gas exchange (oxygen and carbon dioxide) and not primarily involved in nutrient transportation. Choice B, the digestive system, is responsible for breaking down food and absorbing nutrients but does not transport nutrients throughout the body. Choice D, the nervous system, controls and coordinates body functions through electrical signals and is not directly involved in nutrient transportation.
Which part of the brain controls balance and coordination?
- A. Cerebrum
- B. Cerebellum
- C. Medulla
- D. Thalamus
Correct Answer: B
Rationale: The cerebellum is the correct answer as it is the part of the brain responsible for controlling balance and coordination in the body. It receives input from various parts of the brain, spinal cord, and sensory systems to help coordinate voluntary movements. The cerebrum (choice A) is mainly involved in higher brain functions such as thinking, decision-making, and voluntary movements but not specifically balance and coordination. The medulla (choice C) is essential for functions like breathing, heart rate, and blood pressure regulation but not primarily for balance and coordination. The thalamus (choice D) acts as a relay station for sensory information but is not primarily responsible for balance and coordination.
Which of the following glands produces growth hormone?
- A. Pituitary
- B. Thyroid
- C. Adrenal
- D. Pancreas
Correct Answer: A
Rationale: The correct answer is A: Pituitary. The pituitary gland, also known as the master gland, produces growth hormone, which plays a crucial role in stimulating growth and cell reproduction. Choice B, the thyroid gland, primarily produces hormones that regulate metabolism, not growth hormone. Choice C, the adrenal glands, produce hormones like cortisol and adrenaline, but not growth hormone. Choice D, the pancreas, produces insulin and glucagon for regulating blood sugar levels, not growth hormone.