The correct option is A-3, B-2, C-4, D-1
Explanation
Organisms are classified based on their mode of nutrition, which is the process of obtaining food necessary for health and growth. Broadly, nutrition is categorized into autotrophic (self-synthesizing) and heterotrophic (dependent on others) modes. Heterotrophic nutrition further includes parasitic, saprotrophic, and insectivorous types.
Detailed Analysis
- A. Cuscuta (Parasitic): Cuscuta, commonly known as Amarbel or Dodder, is a non-green plant that lacks chlorophyll. It cannot synthesize its own food and relies entirely on a host plant for nutrients. It develops special roots called haustoria that penetrate the host's tissues to absorb water and nutrients. Hence, it is a parasite.
- B. Mushroom (Saprotrophic): Mushrooms belong to the kingdom Fungi. They lack chlorophyll and cannot perform photosynthesis. Instead, they obtain nutrition by secreting digestive enzymes onto dead and decaying organic matter and absorbing the dissolved nutrients. This mode of nutrition is called saprotrophic.
- C. Pitcher Plant (Insectivorous): The Pitcher plant (Nepenthes) is green and carries out photosynthesis. However, it typically grows in nitrogen-deficient soils. To fulfill its nitrogen requirements, it traps and digests insects using modified leaf structures. Therefore, it is classified as an insectivorous plant.
- D. Algae (Autotrophic): Algae are simple, plant-like organisms that contain chlorophyll. They are capable of synthesizing their own food using sunlight, carbon dioxide, and water through the process of photosynthesis. Thus, they are autotrophic.
Key Takeaway
Autotrophs (e.g., Algae) produce their own food; Saprotrophs (e.g., Fungi) feed on dead matter; Parasites (e.g., Cuscuta) derive nutrients from a living host; and Insectivorous plants (e.g., Pitcher Plant) supplement their diet with insects to overcome nitrogen deficiency.