Practice TEAS Science Test

Correct Answer: B

Rationale: Cystic fibrosis is the correct answer because it is a genetic condition that primarily affects the respiratory system by causing mucus buildup in the lungs, leading to breathing difficulties and recurrent lung infections. This condition is caused by mutations in the CFTR gene. Asthma (A) is a chronic respiratory condition characterized by inflammation and narrowing of the airways but is not a genetic disorder. Mycosis (C) refers to fungal infections and does not specifically affect the respiratory system. Surfactant Deficiency (D) is a condition where insufficient surfactant is produced in the lungs, leading to respiratory distress in newborns, but it is not primarily a genetic condition affecting the respiratory system.

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: B

Rationale: The correct answer is B: Sebaceous gland. Sebaceous glands produce sebum, an oily substance that helps moisturize the skin and hair. The sudoriferous gland produces sweat, not oil. The hair follicle anchors the hair to the skin, it does not produce oil. Melanocytes are responsible for producing melanin, the pigment that gives skin its color, not oil. Therefore, the sebaceous gland is the structure responsible for producing oil to keep the skin and hair moisturized.

Correct Answer: A

Rationale: The correct answer is A: Mediastinum. The mediastinum is the space between the lungs that contains vital structures such as the heart, major blood vessels, esophagus, and trachea. It separates the lungs into right and left compartments. The pericardial cavity (B) is the space that surrounds the heart within the mediastinum. The pleural cavity (C) is the space between the lungs and the chest wall, not between the lungs themselves. Thoracic space (D) is a vague term and does not specifically refer to the space between the lungs.

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.