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 because the pericardium is actually a double-walled sac around the heart, not a single-walled layer. The outer layer is the fibrous pericardium, and the inner layer is the serous pericardium. Choice A is correct because the pericardial fluid between the layers reduces friction. Choice C is also correct because the pericardium helps prevent overfilling of the heart. Choice D is correct as well, as the pericardium does protect and anchor the heart. Therefore, the only incorrect statement is B, as the pericardium is not a single-walled layer.

Correct Answer: B

Rationale: The correct answer is B: Lymph nodes. Lymph nodes are responsible for filtering lymph, which carries waste products and pathogens, supporting the immune system by trapping and destroying harmful substances. Lymph nodes contain immune cells that help fight infections. The other choices are incorrect because: A: Kidneys filter blood and regulate fluid balance. C: Pancreas produces digestive enzymes and insulin. D: Liver detoxifies harmful substances and processes nutrients.

Correct Answer: D

Rationale: The correct answer is D: Epiglottis. The epiglottis is a flap of tissue that covers the opening of the windpipe (trachea) during swallowing to prevent food from entering it. Step-by-step rationale: 1. During swallowing, the epiglottis moves down to cover the trachea. 2. This action directs food to the esophagus (B), a muscular tube that carries food to the stomach. 3. The pharynx (A) is a common passageway for both food and air but does not prevent food from entering the windpipe. 4. The larynx (C) is involved in sound production but does not prevent food from entering the windpipe. In summary, the epiglottis is the correct structure as it specifically functions to protect the windpipe during swallowing, while the other choices do not have this specific function.

Correct Answer: D

Rationale: The correct answer is D because a positive correlation indicates that as one variable increases, the other variable also increases. In this case, when plotting rainfall against plant length, if the line trends to the upper right, it shows that as rainfall increases, the plant length also increases. This demonstrates a positive correlation. A is incorrect because it describes a negative correlation where an increase in rainfall leads to a decrease in plant stem length. B is incorrect as it suggests a positive correlation between rainfall and roots length. C is incorrect as a line trending to the lower right also indicates a negative correlation between the variables.