Reasoning: The endoplasmic reticulum (ER) is a system of interconnected membranes forming channels throughout the cytoplasm. It is continuous with the nuclear membrane and helps transport materials within the cell.

Reasoning: Most enzymes are proteins, and proteins are synthesized on ribosomes.

Reasoning: Mitochondria are known as the "powerhouses" of the cell because they carry out cellular respiration, producing ATP (energy).

Reasoning: Both cells are adapted for efficient exchange of substances: Red blood cells have a biconcave shape, increasing surface area for oxygen exchange. Root hair cells have long projections that increase surface area for water and mineral absorption.

Reasoning: B is muscle cell (elongated, spindle-shaped). Muscle cells are specialized to contract when stimulated, producing movement.

Reasoning: The nucleus, mitochondria, and chloroplasts contain their own DNA. Lysosomes are membrane-bound organelles containing digestive enzymes and do not contain DNA.

Reasoning: The Smooth Endoplasmic Reticulum (SER) synthesizes lipids, including phospholipids, which are major components of cell membranes.

Reasoning: The cytoskeleton maintains cell shape, provides mechanical support, enables movement of organelles, and participates in cell division. It consists of different proteins, not a single type.

Reasoning: Normal red blood cells have a biconcave disc shape, which increases surface area for efficient gas exchange and allows flexibility to pass through narrow capillaries.

Reasoning: Chloroplasts are photosynthetic plastids. Chromoplasts contain pigments and provide colour variety. Leucoplasts store food materials.

Reasoning: Ribosomes are formed in the nucleolus of the nucleus and then move into the cytoplasm, where they function in protein synthesis. They are non-membranous and may be free in cytoplasm or attached to RER, so other options are incorrect.