The polysaccharide that forms the major structural component of plant cell walls is: MCQ with Answer and Explanation

Explanation:
The nucleus is bounded by a double membrane called the nuclear envelope, not a single membrane. It houses the nucleolus, which is the site of ribosomal RNA synthesis. The nuclear envelope is perforated by nuclear pores that regulate the bidirectional transport of molecules, including the export of mRNA to the cytoplasm. Thus, statements 2 and 3 are correct.

Explanation:
Ascariasis is a helminthic infection caused by the intestinal roundworm Ascaris lumbricoides. Ringworm (dermatophytosis) is a superficial fungal infection of the skin, hair, or nails caused by dermatophytes like Microsporum. Amoebiasis is an intestinal infection caused by the protozoan parasite Entamoeba histolytica, not a bacterium. Thus, statements 1 and 2 are correct.

Explanation:
Osmotic pressure (OP) is a colligative property of a solution, meaning it depends on the number of solute particles dissolved in a given volume of solvent, not on the nature or size of the particles. It is defined as the hydrostatic pressure that must be applied to a solution to prevent the net flow of water (osmosis) into the solution across a semipermeable membrane. According to the van't Hoff equation, osmotic pressure is directly proportional to the molar concentration of solute particles and the absolute temperature. The more concentrated the solution, the higher its osmotic pressure.