Kingdom Plantae is characterized by: cell walls made of cellulose, multicellularity, photosynthetic autotrophic nutrition (producing own food using sunlight), and presence of chloroplasts. Option B 'Saprophytic mode of nutrition' is NOT a characteristic of Plantae - saprophytic nutrition involves absorbing nutrients from dead organic matter, which is characteristic of Fungi, not plants. Plants are primarily photosynthetic, not saprophytic. Therefore, B is the correct answer to this 'not a characteristic' question.