निम्नलिखित समूहों में से किनमें ऐसी जातियाँ होती हैं, जो अन्य जीवों के साथ सहजीवी संबंध बना सकती हैं?
- 1.नाइडेरिया
- 2.कवक (फंजाई)
- 3.आदिजंतु (प्रोटोजोआ)
नीचे दिए गए कूट का प्रयोग कर सही उत्तर चुनिए।
Read this question in English
Which of the following have species that can establish symbiotic relationship with other organisms?
1. Cnidarians
2. Fungi
3. Protozoa
Select the correct answer using the code given below.
(a) 1 and 2 only · (b) 2 and 3 only · (c) 1 and 3 only · (d) 1, 2 and 3
उत्तर और व्याख्या · explanation in English
Answer: (d) 1, 2 और 3
All three groups contain species that live in close, often mutually beneficial, partnerships with other organisms. Reef-building corals (cnidarians) host photosynthetic zooxanthellae; fungi form lichens and mycorrhizae; and many protozoa live as symbionts, some carrying algae inside their own cells.
- ✓ 1. Corals, which are cnidarians, house zooxanthellae in their tissues; the algae supply sugars from photosynthesis and the coral gives them shelter and carbon dioxide.
- ✓ 2. Fungi team up with algae or cyanobacteria to form lichens, and with plant roots to form mycorrhizae that help plants absorb phosphorus.
- ✓ 3. Many protozoa live as symbionts; the ciliate Paramecium bursaria, for instance, carries symbiotic Chlorella algae in its cytoplasm. The two benefit each other: the ciliate gives the algae a protected habitat and the algae add to its nutrition through photosynthesis.
Remember · Mutualism examples: coral + zooxanthellae, fungus + alga (lichen), fungus + root (mycorrhiza), Paramecium bursaria + algae, legume + Rhizobium.
📘 Read it in NCERT: Class 9 Exploration, Ch 12 (practise this chapter) · Class 12 Biology, Ch 11 (practise this chapter) · Class 9 Exploration, Ch 12 (practise this chapter)
Sources
- NOAA National Ocean Service, Corals Tutorial: What is Zooxanthellae? ↗ “Most reef-building corals contain photosynthetic cells called zooxanthellae that live in their tissues. The corals and zooxanthellae have a mutualistic relationship.”
- NCERT Class 9 · Exploration, Chapter 12 “Cnidarians, such as Hydra (Fig. 12.14), jellyfish (Fig. 12.16b) and corals show a major change in body organisation.”
- NCERT Class 12 · Biology, Chapter 11 “Lichens represent an intimate mutualistic relationship between a fungus and photosynthesising algae or cyanobacteria. Similarly, the mycorrhizae are associations between fungi and the roots of higher plants.”
- NCERT Class 9 · Exploration, Chapter 12 “Some of the fungi establish a mutualistic (symbiotic) relationship with other organisms while others live as parasites, and cause diseases in plants and animals.”
- Kodama et al., 'Effects of the Symbiotic Chlorella variabilis on the Host Ciliate Paramecium bursaria Phenotypes' (PubMed Central) ↗ “The relationship between P. bursaria and symbiotic Chlorella spp. is characterized by mutualism, in which both organisms benefit from this association.”
Question and answer: UPSC's official GS Paper I (2021, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 1 Oct 2026 (how we verify). ·