Practice TEAS Science Test

Correct Answer: C

Rationale: The correct answer is C: Pyruvic acid. In glycolysis, glucose is broken down into pyruvic acid. This process involves a series of enzymatic reactions that result in the production of pyruvic acid, which is a crucial intermediate in cellular respiration. Pyruvic acid can then enter the citric acid cycle to further extract energy in the form of ATP. Rationale for other choices: A: ATP is produced during glycolysis, but it is not the end product. B: NADPH is not the end product of glucose breakdown in glycolysis; it is a reducing agent used in various metabolic pathways. D: Oxygen is not directly produced as a result of glucose breakdown in glycolysis; oxygen is utilized in later stages of cellular respiration.

Correct Answer: B

Rationale: The correct answer is B: To filter waste from the blood. The lymphatic system includes lymph nodes and vessels that help filter out waste, toxins, and pathogens from the blood. Lymphocytes in the lymph nodes also play a key role in immune responses. The other choices (A, C, D) are incorrect because the lymphatic system is not responsible for transporting oxygen (A), producing red blood cells (C), or regulating body temperature (D).

Correct Answer: B

Rationale: The correct answer is B: Alveoli. Alveoli are tiny air sacs in the lungs where gas exchange occurs. Oxygen from the air we breathe passes into the blood vessels surrounding the alveoli, while carbon dioxide from the blood moves into the alveoli to be exhaled. The other choices are incorrect because: A: Trachea is the windpipe that carries air to and from the lungs, but gas exchange does not occur there. C: Bronchioles are small air passages that branch off the bronchi, leading air to the alveoli, but they are not the site of gas exchange. D: Diaphragm is a muscle that helps with breathing by expanding and contracting the chest cavity, but it is not directly involved in gas exchange.

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: 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.