Correct Answer: C

Rationale: The correct answer is 'Cellulose.' Cellulose is the main component of the cell wall in plant cells, providing structural support and rigidity. Starch, while a carbohydrate, is a storage form of glucose in plants and not a component of the cell wall. Glucose is a simple sugar that can be used as an energy source but is not the main component of the cell wall. Chitin is a structural carbohydrate found in the exoskeleton of arthropods and fungi, not in plant cell walls.

Correct Answer: C

Rationale: This is an example of a synthesis reaction because simpler substances (water and carbon dioxide) are combined to form a more complex substance (glucose) in the presence of sunlight. Choice A (Decomposition reaction) involves breaking down a compound into simpler substances, which is the opposite of what happens in photosynthesis. Choice B (Combustion reaction) typically involves a substance reacting with oxygen to produce heat and light, not the formation of glucose and oxygen from simpler substances. Choice D (Double displacement reaction) involves an exchange of ions between two compounds, which is not what occurs in photosynthesis.

Correct Answer: C

Rationale: RNA interference (RNAi) is a biological process that involves the silencing of gene expression by inhibiting the translation of mRNA or by degrading mRNA molecules. This mechanism plays a crucial role in regulating gene expression and can be used to selectively silence specific genes. By interfering with the expression of specific genes, RNAi can downregulate protein production from those genes. Therefore, option C, 'Inhibits the expression of specific genes,' is the correct role of RNA interference in silencing genes. Options A, B, and D are incorrect because RNA interference does not increase protein production, promote gene mutation, or repair damaged DNA; its primary function is to inhibit gene expression by degrading or interfering with mRNA.

Correct Answer: A

Rationale: In the given reaction, the complete ionic equation is: 2H+(aq) + 2Cl-(aq) + Ba2+(aq) + 2OH-(aq) → 2H2O(l) + Ba2+(aq) + 2Cl-(aq). Spectator ions (Ba2+ and Cl-) do not participate in the net ionic equation, which simplifies to: 2H+(aq) + 2OH-(aq) → 2H2O(l). This equation represents the significant species involved in the reaction, showcasing the formation of water from the combination of hydrogen ions and hydroxide ions, resulting in the production of water molecules.

Correct Answer: D

Rationale: The primary function of the large intestine is to absorb water and electrolytes from the indigestible food matter that passes through it. This absorption process aids in the formation of solid waste (feces) before it is excreted from the body. Choices A, B, and C are incorrect because the large intestine does not primarily digest and absorb nutrients, store and mix food, or break down carbohydrates. These functions are primarily carried out by the small intestine.