Which of the following are the two major zones of the respiratory system?

Correct Answer: D

Rationale: The two major zones of the respiratory system are the conducting zone and the respiratory zone. The conducting zone encompasses structures like the nasal cavity, pharynx, larynx, trachea, bronchi, and bronchioles, which serve to transport air into the lungs. On the other hand, the respiratory zone includes the respiratory bronchioles, alveolar ducts, and alveoli, where the crucial gas exchange process between the air in the lungs and the blood occurs. Choices A, B, and C are incorrect as they do not represent the major zones of the respiratory system but rather individual structures within the system.

Correct Answer: C

Rationale: Isotopes are defined as atoms of the same element that have the same number of protons in their nucleus but different numbers of neutrons. This leads to variations in atomic mass for isotopes of an element. The different number of neutrons in isotopes results in differences in their atomic mass and properties while still belonging to the same element. Choice A is incorrect because isotopes do not have different ionic charges, they have the same chemical properties. Choice B is incorrect because isotopes are not atoms of elements within the same group on the periodic table; they are variants of the same element. Choice D is incorrect because isotopes of an element have the same electron configuration, differing only in the number of neutrons in the nucleus.

Correct Answer: A

Rationale: The epiglottis is the cartilaginous flap that protects the larynx from water or food while still allowing the flow of air. When we swallow, the epiglottis covers the entrance to the larynx, preventing food or liquid from entering the airway and instead directing them towards the esophagus for digestion. Choice B, bronchioles, are small airway branches within the lungs and are not involved in protecting the larynx from food or water. Choice C, epithelium, refers to the tissue that lines the surfaces of organs and structures in the body, but it is not the specific structure that protects the larynx as described. Choice D, tongue, plays a role in taste, speech, and swallowing, but it is not the cartilaginous flap that protects the larynx.

Correct Answer: A

Rationale: The correct answer is A: 'to enclose, protect, support, and separate muscle tissue.' Fascia is a connective tissue that surrounds muscles, providing structural support, protecting them from friction and injury, and helping in movement. Choice B is incorrect as tendons are responsible for connecting muscle tissue to bone. Choice C is incorrect as the contractile unit of muscle is the sarcomere, not fascia. Choice D is incorrect as the process described relates to muscle contraction mechanisms involving actin and myosin, not the function of fascia.

Correct Answer: A

Rationale: The correct answer is A. A strong acid is defined as an acid that completely ionizes in water, meaning it dissociates fully into its constituent ions in solution. This characteristic differentiates strong acids from weak acids, which do not fully dissociate in water. Choice B is incorrect because the number of protons donated does not solely define the strength of an acid. Choice C is incorrect as strong acids are not defined by the presence of metal atoms, and Choice D is incorrect because all acids can decompose, but the strength of the acid is based on its ability to ionize in water.