Practice TEAS Science Test

Correct Answer: D

Rationale: The correct answer is D: Pia mater. Pia mater is the innermost meningeal layer that is a thin membrane containing nerves and blood vessels. It directly covers the brain and spinal cord, supplying nourishment to the underlying cells. Arachnoid mater (A) is the middle meningeal layer that does not contain nerves and blood vessels. Dura mater (B) is the tough outermost layer that does not supply nourishment. Periosteum (C) is a connective tissue covering bones, not the meninges.

Correct Answer: A

Rationale: The correct answer is A: Skin. An organ is a group of tissues that work together to perform specific functions in the body. Skin is the body's largest organ, made up of different layers that serve various functions like protection, sensation, and regulation of body temperature. Neuron (B) is a cell type, brainstem (C) is a part of the brain, and DNA (D) is a molecule, not an organ. Skin best fits the definition of an organ, making it the correct choice.

Correct Answer: B

Rationale: Bile plays a crucial role in digestion by emulsifying fats. It breaks down large fat molecules into smaller droplets, increasing the surface area for enzymes to digest fats. This process aids in the absorption of fat-soluble vitamins and fatty acids. Choices A, C, and D are incorrect as bile does not directly break down carbohydrates, neutralize stomach acid, or absorb proteins in digestion.

Correct Answer: B

Rationale: The correct answer is B: Gallbladder. The gallbladder stores and concentrates bile produced by the liver, releasing it into the small intestine to aid in digestion. The liver produces bile but does not store it. The pancreas produces digestive enzymes, not bile. The stomach produces gastric juices for digestion, not bile.

Correct Answer: B

Rationale: The correct answer is B: Medulla oblongata. The medulla oblongata, located in the brainstem, controls essential functions like breathing and heart rate. It contains centers that regulate these automatic processes. The cerebrum (A) is responsible for higher brain functions, not controlling basic physiological functions. The thalamus (C) serves as a relay station for sensory information, not for regulating breathing and heart rate. The cerebellum (D) plays a role in coordination and movement, not in controlling vital functions like breathing and heart rate.