Practice TEAS Science Test

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: C

Rationale: The correct answer is C: IgG. IgG is the only antibody that can cross the placenta due to its smaller size and ability to bind to neonatal Fc receptors. This allows for passive immunity to be transferred from mother to fetus. IgA is mainly found in mucosal secretions, IgD functions as a B cell receptor, and IgM is primarily involved in the primary immune response. IgG is the most abundant antibody in the circulation and plays a crucial role in protecting the fetus from infections.

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.

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: Protein. Proteins are macromolecules composed of amino acids, which always contain nitrogen in their structure. Amino acids have an amine group (-NH2), which is where the nitrogen is found. Fatty acids (choice A) do not contain nitrogen in their structure. Lipids (choice C) and carbohydrates (choice D) also do not contain nitrogen in their basic structure. Therefore, protein is the only macromolecule among the choices that will always contain nitrogen.