Correct Answer: A

Rationale: The gallbladder is a small organ located beneath the liver that plays a crucial role in the digestive system. Its main function is to store and concentrate bile, a digestive fluid produced by the liver. Bile is released from the gallbladder into the small intestine to help with the digestion and absorption of fats. The gallbladder acts as a reservoir for bile, allowing it to be released in a controlled manner when needed to aid in the digestion of fatty foods. Option A is the correct answer as it accurately describes the main function of the gallbladder. Choices B, C, and D are incorrect because the gallbladder does not produce digestive enzymes, absorb nutrients, or neutralize stomach acid. These functions are carried out by other organs in the digestive system, such as the pancreas, small intestine, and stomach, respectively.

Correct Answer: D

Rationale: The number of protons in an atom is determined by its atomic number. The atomic number represents the number of protons in the nucleus of an atom, which also determines the element's identity. Therefore, the correct answer is (D) Atomic number. Choices (A) Atomic mass, (B) Electron configuration, and (C) Chemical properties are not directly related to the number of protons in an atom. Atomic mass is the total mass of protons, neutrons, and electrons in an atom. Electron configuration refers to the arrangement of electrons in an atom's energy levels, and chemical properties are determined by the arrangement of electrons in the outermost energy level.

Correct Answer: A

Rationale: The correct answer is A: Ribosomes. Ribosomes are the organelles responsible for protein synthesis in the cell. They can be found either freely floating in the cytoplasm or attached to the endoplasmic reticulum. The Golgi apparatus (Choice B) is involved in processing and packaging proteins, not protein production. Mitochondria (Choice C) are responsible for energy production, not protein synthesis. Lysosomes (Choice D) are involved in digestion and waste removal, not protein production.

Correct Answer: A

Rationale: Cell division is the correct answer. It is the process by which a parent cell divides into two or more daughter cells, enabling growth, repair, and reproduction in living organisms. This process ensures that genetic material is accurately passed on to the new cells. Cell differentiation refers to the specialization of cells to perform specific functions, while cell growth is the increase in size or mass of a cell. Cell regeneration involves replacing damaged or lost cells with new ones, where cell division plays a role but is not the primary process of generating new cells. Therefore, in the context of cells producing new cells, cell division is the accurate term.

Correct Answer: B

Rationale: Immunoglobulin G (IgG) is indeed the most prevalent antibody type in the blood and tissue fluids. Its primary functions include neutralizing toxins and viruses, promoting phagocytosis, and activating the complement system. IgG plays a crucial role in long-term immunity and provides passive immunity to newborns by crossing the placenta, safeguarding them from infections. Immediate allergic reactions are mainly mediated by IgE, not IgG. While IgM is known for activating other immune cells, IgG focuses on other key functions within the immune response, such as neutralizing pathogens and enhancing phagocytosis. Therefore, the correct answer is B, as IgG is primarily involved in neutralizing toxins and viruses, rather than the other options presented.