Correct Answer: C

Rationale: A synergist is a muscle that assists the agonist, the primary muscle responsible for a specific movement, in performing that movement. Synergists stabilize joints and provide additional support to the prime mover muscle, enhancing the efficiency and effectiveness of the movement. Choice A, Agonist, refers to the muscle primarily responsible for a specific movement. Choice B, Antagonist, refers to a muscle that opposes the action of the agonist. Choice D, Fixator, refers to a muscle that stabilizes the origin of the prime mover muscle, maintaining the desired position during movement.

Correct Answer: C

Rationale: The correct answer is Acetic acid (CH3COOH) because it is a weak acid that only partially dissociates in water, resulting in a lower concentration of H+ ions compared to strong acids like hydrochloric acid (HCl), sulfuric acid (H2SO4), and nitric acid (HNO3) which completely dissociate in water. Weak acids do not fully ionize in water, leading to a lower concentration of H+ ions in solution. Hydrochloric acid, sulfuric acid, and nitric acid are strong acids that completely dissociate in water, producing a higher concentration of H+ ions. Therefore, they are not examples of weak acids.

Correct Answer: C

Rationale: Proteins are macromolecules made up of long chains of amino acids. Amino acids are the building blocks of proteins and are linked together through peptide bonds to form polypeptide chains, which then fold into specific three-dimensional structures to carry out various functions in the body. Sugars (choice A) are the building blocks of carbohydrates, fatty acids (choice B) are the building blocks of lipids, and nucleotides (choice D) are the building blocks of nucleic acids like DNA and RNA. Therefore, the correct answer is amino acids (choice C), as they are specifically responsible for protein synthesis.

Correct Answer: A

Rationale: The correct answer is A: Epiglottis. The epiglottis is a cartilage flap located at the base of the tongue that covers the trachea during swallowing. Its primary function is to prevent food and liquids from entering the airway and instead directs them towards the esophagus. The glottis (choice B) refers to the space between the vocal cords in the larynx. The larynx (choice C) is the voice box containing the vocal cords responsible for phonation. The pharynx (choice D) is the throat region connecting the mouth and the esophagus, playing a role in both digestion and respiration.

Correct Answer: B

Rationale: - The atomic number (Z) of an element is the number of protons in its nucleus. In this case, the element has an atomic number of 11. - The mass number (A) of an element is the sum of its protons and neutrons. Given that the mass number is 23 and the atomic number is 11, we can calculate the number of neutrons by subtracting the atomic number from the mass number: Neutrons = Mass number - Atomic number = 23 - 11 = 12. - Therefore, the element with atomic number 11 and mass number 23 has 12 neutrons.