Practice TEAS Science Test

Correct Answer: C

Rationale: The correct answer is C because an allergic reaction is triggered by the release of histamine and other inflammatory molecules from mast cells, which are stimulated by Immunoglobulin E. This process leads to symptoms such as hives, itching, swelling, and difficulty breathing. Other choices are incorrect because: A: While integumentary and respiratory systems are involved in allergic reactions, they are not overactive systems but rather respond to the allergen. B: B-cells produce antibodies, not immunoglobulins directly related to allergic reactions. D: Histamine is involved in allergic reactions, but keratin and collagen are not typically associated with allergic responses.

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: D

Rationale: The correct answer is D: Cardiovascular. The cardiovascular system is responsible for transporting dissolved oxygen from the lungs to the spleen. Step 1: Oxygen is inhaled into the lungs during respiration. Step 2: Oxygen diffuses into the bloodstream through the alveoli in the lungs. Step 3: The oxygen-rich blood is pumped by the heart to the spleen and other body tissues. The immune system (A) is responsible for fighting off infections, not oxygen transport. The endocrine system (B) regulates hormones, not oxygen transport. The respiratory system (C) is involved in the exchange of gases in the lungs but does not transport oxygen to the spleen.

Correct Answer: D

Rationale: The correct answer is D: Type O. Type O blood lacks both A and B antigens, making it compatible with all blood types. As a result, it can be safely transfused to individuals with any blood type, earning it the title of the universal donor. Choice A (Type A) has A antigens, Choice B (Type B) has B antigens, and Choice C (Type AB) has both A and B antigens, making them not suitable for universal donation.

Correct Answer: B

Rationale: The correct answer is B: 12 NADPH and 18 ATP. In the Calvin cycle of photosynthesis, each molecule of CO2 requires 2 NADPH and 3 ATP for reduction to glucose. Therefore, to reduce 6 molecules of CO2, you would need 6 x 2 = 12 NADPH and 6 x 3 = 18 ATP. This is why choice B is the correct answer. Choices A, C, and D have incorrect combinations of NADPH and ATP that do not match the stoichiometry of the Calvin cycle for the reduction of CO2 to glucose.