Practice TEAS Science Test

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: 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: 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: B

Rationale: The correct answer is B: Jejunum. The jejunum is the primary site of absorption in the small intestine due to its extensive surface area, presence of villi and microvilli that increase absorption capacity, and higher blood supply compared to other regions. It is where most nutrients such as carbohydrates, proteins, and fats are absorbed. The duodenum (A) is mainly responsible for initial digestion, the ileum (C) absorbs bile salts, vitamin B12, and some nutrients, and the cecum (D) is part of the large intestine and is not involved in nutrient absorption.

Correct Answer: D

Rationale: Platelets play a crucial role in clotting blood. When a blood vessel is damaged, platelets rush to the site to form a plug, preventing excessive bleeding. This process, known as hemostasis, involves platelets adhering to the damaged vessel wall, releasing chemicals to attract more platelets, and forming a clot to stop bleeding. Platelets do not transport oxygen (choice A), fight infection (choice B), or produce antibodies (choice C). Thus, the correct answer is D - Clot blood.