Which of the following is an end product of cellular respiration?

Correct Answer: B

Rationale: The correct answer is B: ATP energy. During cellular respiration, glucose is broken down to produce ATP, which is the primary energy currency of cells. While oxygen is required for cellular respiration to occur, it is not an end product but rather a reactant. Carbon dioxide and water are byproducts of cellular respiration, alongside ATP. Therefore, options A, C, and D are incorrect as they are not end products of cellular respiration.

Correct Answer: D

Rationale: Type O blood is known as the universal donor because it lacks antigens on the surface of red blood cells. This characteristic makes it compatible with all blood types during transfusions. Type A, Type B, and Type AB blood types have specific antigens that can cause adverse reactions if transfused to an incompatible recipient.

Correct Answer: B

Rationale: The correct answer is B: Hydrogen bond. Hydrogen bonds are responsible for holding water molecules together. In a water molecule, the oxygen atom is slightly negative, and the hydrogen atoms are slightly positive, creating a partial positive and negative charge. This polarity allows hydrogen bonds to form between adjacent water molecules. Covalent bonds involve the sharing of electrons, ionic bonds involve transfer of electrons between ions, and peptide bonds are specific to linking amino acids in proteins, which are not relevant to water molecule interactions.

Correct Answer: B

Rationale: Vitamin D is the correct answer. When the skin is exposed to sunlight, it triggers a process where a form of cholesterol in the skin is converted into vitamin D. This vitamin plays a crucial role in aiding calcium absorption in the gut, which is essential for maintaining strong and healthy bones. Vitamin A (Choice A) is important for vision and immune function but is not produced by sunlight exposure. Vitamin K (Choice C) is known for its role in blood clotting and bone metabolism, but it is not produced by sunlight. Vitamin E (Choice D) is an antioxidant that protects cells from damage but is not synthesized in the skin through sunlight exposure.

Correct Answer: B

Rationale: The correct answer is Iron. Iron is essential for the formation of hemoglobin, the protein in red blood cells that binds and transports oxygen throughout the body. Calcium (Choice A), Potassium (Choice C), and Sodium (Choice D) are not directly involved in the formation of hemoglobin and its oxygen-carrying function.