TEAS Practice Test Science

Correct Answer: B

Rationale: The correct answer is B: To exchange gases. The main function of the respiratory system is to facilitate the exchange of oxygen and carbon dioxide between the body and the external environment. This process occurs in the lungs through breathing, where oxygen is taken in and carbon dioxide is expelled. Absorbing nutrients (A) is the function of the digestive system, transporting oxygen (C) is part of the circulatory system's role, and regulating blood pressure (D) is primarily controlled by the cardiovascular system.

Correct Answer: B

Rationale: The correct answer is B: Fight infection. White blood cells are a crucial part of the immune system, responsible for identifying and attacking foreign invaders such as bacteria, viruses, and other pathogens. They play a key role in defending the body against infections and diseases. Choices A, C, and D are incorrect because white blood cells do not primarily function in transporting oxygen, producing antibodies, or regulating body temperature. Oxygen transport is mainly the role of red blood cells, antibody production is the function of B cells, and body temperature regulation involves processes such as sweating and shivering controlled by the hypothalamus.

Correct Answer: B

Rationale: The correct answer is B: Pancreas. The pancreas is responsible for producing insulin because it contains clusters of cells called islets of Langerhans, specifically beta cells, which secrete insulin. The liver (A) plays a role in regulating blood sugar levels but does not produce insulin. The gallbladder (C) stores bile and aids in digestion, not insulin production. The spleen (D) is important for immune function but does not produce insulin. Therefore, the pancreas is the correct choice for producing insulin.

Correct Answer: B

Rationale: The rib cage protects the vital organs such as the lungs and heart by providing a sturdy barrier against external impact. The ribs act as a shield, preventing injuries to these crucial organs. Additionally, the rib cage also aids in the process of respiration by expanding and contracting to allow the lungs to inflate and deflate during breathing. Choices A, C, and D are incorrect because the primary function of the rib cage is to protect the lungs and heart, not the digestive organs, support movement, or regulate body temperature.

Correct Answer: B

Rationale: The correct answer is B: Meiosis Prophase I. Crossing over occurs during Prophase I of meiosis, specifically during the substage called pachytene. This is when homologous chromosomes pair up and exchange genetic material. This process creates genetic diversity among offspring. Choice A, Mitosis Prophase, is incorrect because crossing over does not occur during mitosis, as homologous chromosomes do not pair up in mitosis. Choice C, Meiosis Prophase II, is incorrect because crossing over only occurs during Prophase I, not Prophase II. Choice D, Interphase, is incorrect because crossing over does not occur during interphase, as it is a phase where the cell prepares for division and DNA replication occurs.