Practice TEAS Science Test

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: B

Rationale: The correct answer is B: Hydrogen bond. Water molecules are held together by hydrogen bonds, which form between the hydrogen atom of one water molecule and the oxygen atom of another. This bond is weaker than a covalent bond but still strong enough to keep water molecules attracted to each other. Covalent bonds (choice A) involve the sharing of electrons between atoms, not present in water. Ionic bonds (choice C) involve the transfer of electrons between atoms, not applicable to water. Peptide bonds (choice D) are found in proteins, not in water molecules.

Correct Answer: D

Rationale: The correct answer is D: To regulate blood glucose. The adrenal glands secrete hormones like cortisol and adrenaline, which play a crucial role in regulating blood glucose levels. Cortisol helps increase blood glucose when needed, while adrenaline helps release stored glucose for energy in fight-or-flight situations. Choices A, B, and C are incorrect. A is more related to the thyroid gland, B is produced by the liver, and C is primarily done by the bone marrow.

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: 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.