Practice TEAS Science Test

Correct Answer: A

Rationale: The correct answer is A: Ectoderm. During embryonic development, the nervous system originates from the ectoderm layer. The neural plate forms from the ectoderm, which further develops into the neural tube and neural crest cells, giving rise to the brain, spinal cord, and peripheral nervous system. The other choices, B: Endoderm, C: Gastroderm, and D: Mesoderm, do not give rise to the nervous system. Endoderm forms the innermost layer of organs like the gut, Gastroderm is not a recognized germ layer, and Mesoderm gives rise to structures like muscles, bones, and connective tissues, not the nervous system.

Correct Answer: B

Rationale: The correct answer is B: Larynx. The voice box, also known as the larynx, is responsible for producing sound by manipulating airflow from the lungs. The other choices are incorrect because: A: Alveoli are small air sacs in the lungs for gas exchange. C: Trachea is the windpipe that carries air to and from the lungs. D: Pharynx is the throat region where the nasal and oral cavities meet.

Correct Answer: B

Rationale: The correct answer is B: Measuring wheel and mathematical formula. To measure the volume of a cube, you need to measure the length of one side using a measuring wheel and then use the formula V = s^3, where V is the volume and s is the length of one side. This method is suitable because it directly measures the side length of the cube, which is essential for calculating the volume accurately. Choice A, the triple beam balance, is used for measuring mass, not volume. Choice C, the graduated cylinder, is used to measure the volume of irregularly shaped objects using water displacement method, not ideal for a cube. Choice D, the measuring wheel alone, does not provide the formula for calculating the volume of a cube, making it less suitable compared to choice B.

Correct Answer: B

Rationale: The correct answer is B: Laryngopharynx. The laryngopharynx is part of the pharynx where both the respiratory and digestive systems intersect. It serves as a common passageway for both food and air. When we swallow, the epiglottis covers the larynx to prevent food from entering the trachea. A: The esophagus is solely a passageway for food from the mouth to the stomach. C: The nasopharynx is a part of the upper respiratory tract and not involved in the passage of food. D: The trachea is strictly a passageway for air to enter and exit the lungs.

Correct Answer: B

Rationale: The correct answer is B: Depolarization of the SA node. The P-wave in an ECG represents atrial depolarization, which is initiated by the SA node. This electrical signal spreads through the atria causing them to contract. Choice A is incorrect because the P-wave corresponds to atrial depolarization, not repolarization. Choice C is incorrect as the QRS complex represents ventricular depolarization. Choice D is incorrect as the T-wave represents ventricular repolarization. Therefore, the SA node depolarization is accurately represented by the P-wave in an ECG.