Name two structures present only in (a) Plant cells (b) Animal cells

Plant cells contain two distinctive structures not found in animal cells: cell wall and chloroplasts. The cell wall is a rigid outer layer composed primarily of cellulose that surrounds the plasma membrane, providing structural support, protection, and shape to plant cells. This tough barrier allows plants to maintain upright growth without a skeletal system and protects against mechanical stress and pathogen invasion. Chloroplasts are the photosynthetic organelles containing chlorophyll that enable plants to convert light energy into chemical energy through photosynthesis. Another plant-specific feature worth noting is the large central vacuole, which occupies up to 90% of the cell volume and functions in storage, waste disposal, and maintaining turgor pressure.

Animal cells have two structures typically not present in plant cells: centrioles and lysosomes. Centrioles are cylindrical structures composed of microtubules that occur in pairs and play a crucial role in organizing the spindle fibers during cell division, helping separate chromosomes. Lysosomes are membrane-bound organelles containing digestive enzymes that break down worn-out organelles, food particles, and foreign materials. They function as the cell's waste disposal system and are particularly abundant in animal cells that engulf particles through phagocytosis, such as white blood cells. These structural differences reflect the distinct lifestyles and challenges faced by plant and animal organisms.