TEAS Practice Test Science

Correct Answer: B

Rationale: The correct answer is B: Parathyroid hormone. PTH is produced by the parathyroid glands and plays a crucial role in regulating calcium levels in the blood. It increases calcium levels by stimulating the release of calcium from bones, enhancing calcium absorption in the intestines, and reducing calcium excretion in the kidneys. Insulin (A) regulates blood sugar levels, not calcium. Thyroid hormone (C) controls metabolism, not calcium levels. Glucagon (D) increases blood sugar levels, not calcium.

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: C

Rationale: The correct answer is C: Mitochondria. Mitochondria are known as the powerhouse of the cell because they are responsible for producing ATP through cellular respiration. This process involves the breakdown of glucose to generate energy in the form of ATP. Ribosomes (A) are responsible for protein synthesis, the nucleus (B) houses the cell's genetic material, and the endoplasmic reticulum (D) is involved in protein synthesis and lipid metabolism, but not ATP production. Mitochondria's unique structure and enzymes make them the primary site for ATP production in the cell.

Correct Answer: B

Rationale: The correct answer is B: To control body movement and coordination. The nervous system is responsible for receiving sensory input, processing information, and sending signals to control muscle movement and coordination. It includes the brain, spinal cord, and nerves. Choice A is incorrect as the immune system fights infection. Choice C is incorrect as metabolism is regulated by the endocrine system. Choice D is incorrect as oxygen transportation is the function of the circulatory system, not the nervous system.

Correct Answer: C

Rationale: The correct answer is C: Lactic acid and CO2. During anaerobic respiration in humans, glucose is broken down into lactic acid and a small amount of CO2. This process occurs in the absence of oxygen, typically during high-intensity exercise when oxygen supply is limited. Lactic acid buildup causes muscle fatigue. Explanation for why other choices are incorrect: A: Ethyl alcohol and CO2 - This is the byproduct of fermentation in yeast, not human anaerobic respiration. B: Ethyl alcohol only - Ethyl alcohol is not produced during human anaerobic respiration. D: Lactic acid only - While lactic acid is indeed produced during anaerobic respiration in humans, a small amount of CO2 is also generated as a byproduct.