Correct Answer: B

Rationale: The correct answer is B: Artery. Arteries carry oxygen-rich blood away from the heart to various parts of the body. Veins, on the other hand, carry blood back to the heart. Capillaries are tiny blood vessels where oxygen and nutrients are exchanged with tissues. Venules are small veins that collect blood from capillaries, not from the heart, making them incorrect in this context.

Correct Answer: A

Rationale: The correct answer is 'Ionic.' Ionic bonds are formed in salts through the transfer of electrons between atoms, leading to the attraction between positively and negatively charged ions. This results in a stable ionic compound, such as common table salt (sodium chloride). Nonpolar covalent, polar covalent, and peptide bonds are not typically found in salts. Nonpolar covalent bonds involve the equal sharing of electrons, polar covalent bonds involve unequal sharing of electrons, and peptide bonds are specific to proteins, not salts.

Correct Answer: B

Rationale: The left ventricle is the chamber responsible for pumping oxygenated blood from the heart to the body. It receives oxygen-rich blood from the left atrium and contracts to push this blood out to the rest of the body through the aorta. The right ventricle pumps deoxygenated blood to the lungs for oxygenation, making choices A, C, and D incorrect for this function. Therefore, the correct answer is B, the Left ventricle.

Correct Answer: B

Rationale: The correct answer is B because the heartbeat actually begins when the heart muscles relax, allowing the chambers to fill with blood. The contraction phase follows, which propels blood out of the heart. The other statements are accurate in describing the normal sequence of events in the heart's functioning: the atria contract to push blood into the ventricles, the valves close to prevent backflow of blood, and the ventricles contract to pump blood out of the heart.

Correct Answer: B

Rationale: Platelets are responsible for blood clotting. They help prevent excessive bleeding by forming clots at the site of blood vessel injuries. Platelets release chemicals that initiate the clotting process, leading to the formation of a stable clot that stops bleeding. Red blood cells are primarily responsible for carrying oxygen throughout the body and do not play a direct role in clotting. White blood cells are part of the immune system, fighting off infections and foreign invaders. Plasma is the liquid component of blood that carries various substances such as nutrients, hormones, and waste products, but it is not directly involved in clotting.