TEAS 7 science practice

Correct Answer: C

Rationale: The involuntary reflex arc that withdraws your hand from a hot object involves both the central nervous system (CNS) and the peripheral nervous system (PNS). When your hand touches a hot object, sensory neurons in the PNS detect the heat and send signals to the spinal cord in the CNS. The spinal cord processes this information and sends a signal back through motor neurons in the PNS to move your hand away from the hot object. This coordinated response requires the collaboration of both the CNS and PNS to protect the body from harm. Choice A is incorrect because the reflex arc involves more than just the central nervous system. Choice B is incorrect because the reflex arc involves more than just the peripheral nervous system. Choice D is incorrect because the reflex arc also involves motor neurons, not just sensory neurons.

Correct Answer: B

Rationale: The correct term for the process of a gas changing directly into a solid is deposition. During deposition, gas particles lose energy and transition directly into the solid state without passing through the liquid phase. Sublimation, on the other hand, is the process in which a solid changes directly into a gas without going through the liquid phase. Condensation is the process where gas changes into a liquid state. Evaporation, on the contrary, is the conversion of a liquid to a gas. Therefore, the correct answer is B, deposition.

Correct Answer: C

Rationale: Synergistic muscles are groups of muscles that work together in a coordinated manner to produce a specific movement. They synchronize their actions to achieve a common goal efficiently. In contrast, antagonistic muscles work in opposing directions, and agonistic muscles, also known as prime movers, are responsible for initiating a movement. Flexors and extensors represent muscles that perform contrasting actions around a joint, such as bending and straightening. Therefore, the correct answer is C - 'Synergistic muscles,' as they collaborate to facilitate a specific movement, unlike the other choices which describe different muscle functions within the body.

Correct Answer: D

Rationale: The correct answer is D. Unsaturated fatty acids are characterized by the presence of double or triple bonds in their carbon chain. These bonds introduce kinks in the chain, preventing tight packing, and resulting in a lower melting point compared to saturated fatty acids. Choice A is incorrect because unsaturated fatty acids are typically liquid at room temperature due to their kinked structure. Choice B is incorrect because unsaturated fatty acids contain double or triple bonds, not only single bonds. Choice C is incorrect as unsaturated fatty acids have a lower melting point compared to saturated fatty acids.

Correct Answer: A

Rationale: The diaphragm is the primary muscle responsible for inhalation. When it contracts, it moves downward, increasing the volume of the thoracic cavity and creating a pressure gradient that allows air to flow into the lungs. While the intercostal muscles also play a role in expanding the chest cavity during inhalation, the diaphragm is the main muscle involved in this process. Abdominal muscles and pectoral muscles are not directly involved in the process of inhalation.