Practice TEAS Science Test

Correct Answer: B

Rationale: The primary function of white blood cells is to fight infection. They are key components of the immune system, identifying and attacking pathogens like bacteria and viruses. White blood cells produce antibodies to neutralize invaders. This function helps the body defend against illnesses and maintain overall health. Choices A, C, and D are incorrect because carrying oxygen (A) is primarily done by red blood cells, transporting nutrients (C) is mainly performed by blood plasma, and transporting waste (D) is mainly the role of the kidneys and liver.

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: C

Rationale: The correct answer is C: Large intestine. The large intestine is responsible for absorbing water and forming feces as it reabsorbs water from the indigestible food particles that pass through it, leading to the formation of solid waste (feces). The stomach (A) primarily breaks down food with gastric juices. The small intestine (B) is where most nutrient absorption occurs, not water absorption for feces formation. The esophagus (D) is a muscular tube that carries food from the mouth to the stomach, with no role in water absorption or feces formation.

Correct Answer: A

Rationale: The correct answer is A: To transport oxygen and nutrients. The cardiovascular system is responsible for circulating blood throughout the body to deliver oxygen and nutrients to tissues and organs. This function supports cell metabolism and overall body function. Choice B is incorrect because while the cardiovascular system does play a role in blood pressure regulation, it is not its primary function. Choice C is incorrect as digestion is primarily carried out by the digestive system. Choice D is incorrect as waste filtration is mainly performed by the excretory system.

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.