Practice Science TEAS Test

Correct Answer: B

Rationale: The correct answer is B: Retina. The retina is a layer of light-sensitive cells located at the back of the eye that detects light and converts it into signals for the brain through the optic nerve. The iris (A) controls the amount of light entering the eye, the lens (C) helps to focus light onto the retina, and the pupil (D) regulates the amount of light entering the eye, but they do not convert light into signals for the brain like the retina does.

Correct Answer: D

Rationale: The correct answer is D because the liver filters and detoxifies digestion byproducts. It processes nutrients from food, removes toxins, and metabolizes drugs. Choice A is incorrect because the liver produces bile, not just for digestion but also for waste elimination. Choice B is incorrect as the gallbladder stores bile. Choice C is incorrect as the liver converts waste ammonia into urea as part of the metabolic process, not specifically related to digestion.

Correct Answer: B

Rationale: The correct answer is B: Pineal gland. The pineal gland secretes the hormone melatonin, which plays a crucial role in regulating the body's circadian rhythm. Melatonin helps control the sleep-wake cycle, making it responsible for maintaining the body's internal clock. The other choices are incorrect because the thyroid gland regulates metabolism (A), the pancreas regulates blood sugar levels (C), and the hypothalamus controls various bodily functions but is not directly responsible for maintaining the circadian rhythm (D).

Correct Answer: A

Rationale: The correct answer is A: Cerebrum. The cerebrum is responsible for controlling voluntary muscle movements as it houses the motor cortex, which is involved in planning, executing, and coordinating voluntary movements. It receives and processes sensory information and sends out motor commands. The cerebellum (B) mainly coordinates balance, posture, and fine motor movements, not voluntary muscle movements. The medulla oblongata (C) controls vital functions like breathing and heart rate, not voluntary muscle control. The thalamus (D) acts as a relay station for sensory information but is not directly involved in controlling voluntary muscle movements.

Correct Answer: B

Rationale: The correct answer is B: Adhesion. Water is considered a universal solvent because of its strong ability to adhere to other substances and dissolve a wide range of solutes. This property is essential for water to dissolve various molecules and ions, making it an effective solvent in nature. Cohesion (A) refers to water molecules sticking to each other, not to other substances. Molarity (C) is a measure of concentration, not a property of water as a solvent. Dilution (D) refers to the process of reducing the concentration of a solute in a solution, not the reason why water is a universal solvent.