Correct Answer: C

Rationale: Atrial systole is the phase of the cardiac cycle during which the atria contract, pushing blood into the ventricles. This occurs after the atria have been filled during atrial diastole. Ventricular systole refers to the phase when the ventricles contract to push blood out of the heart, not when the atria contract. Ventricular diastole is the phase when the ventricles relax and fill with blood, not when the atria contract. Therefore, the correct answer is atrial systole as it specifically describes the atrial contraction phase.

Correct Answer: B

Rationale: Volume refers to the amount of space occupied by an object. It is a measure of the three-dimensional space that an object occupies. Mass, on the other hand, refers to the amount of matter in an object, weight is the force of gravity acting on an object, and density is the mass of an object per unit volume. In this context, volume is the most appropriate choice as it directly relates to the amount of space an object occupies.

Correct Answer: B

Rationale: An unsaturated solution is a solution that contains less solute than the maximum amount it could dissolve at a specific temperature and pressure. In an unsaturated solution, more solute can still be added and dissolved in the solvent. Choice A, a saturated solution, refers to a solution in which the maximum amount of solute has been dissolved at a specific temperature and pressure, leading to equilibrium. Choice C, a supersaturated solution, contains more solute than it can normally hold at a specific temperature and pressure, achieved through special conditions followed by rapid cooling or evaporation. Choice D, a concentrated solution, refers to a solution with a high amount of solute compared to the amount of solvent, regardless of reaching the saturation point.

Correct Answer: A

Rationale: - Messenger RNA (mRNA) carries genetic information from the DNA in the nucleus to the ribosomes in the cytoplasm for protein synthesis. - Ribosomal RNA (rRNA) is a structural component of ribosomes, which are the cellular machinery responsible for protein synthesis. - Transfer RNA (tRNA) is responsible for bringing amino acids to the ribosome during protein synthesis. Options B, C, and D are incorrect: - Option B lists DNA, RNA, and protein, which are biomolecules but not the three main types of RNA. - Option C lists nitrogenous bases (adenine, guanine, cytosine, and thymine) found in DNA, not types of RNA. - Option D lists components of nucleotides (deoxyribose, ribose, and phosphate), which are building blocks of nucleic

Correct Answer: A

Rationale: Elements within the same group share similar electron configurations in their outermost shells, resulting in comparable chemical properties. Helium and Neon both belong to Group 18 (Noble Gases), explaining their similarities. Boron, Carbon, and Oxygen are not in the same group as Helium on the periodic table. Boron is in Group 13, Carbon is in Group 14, and Oxygen is in Group 16, which are different from Helium's Group 18.