Biology : Taxonomy Part-IV

Total Questions: 40

31. With reference to 'Gucchi' sometimes mentioned in the news, consider the following statements : [I.A.S. (Pre) 2022]

  1. It is a fungus.
  2. It grows in some Himalayan forest areas.
  3. It is commercially cultivated in the Himalayan foothills of north-eastern India.

Which of the statements given above is/are correct?

Correct Answer: (c) 1 and 2
Solution:Gucchi mushroom (morels) is a species of fungus in the family Morchellaceae of the Ascomycota. They are pale yellow in color with large pits and ridges on the surface of the cap, raised on a large white stem. Gucchi is known to be one of the most expensive mushrooms. Apart from its flavor, Gucchi also owes its high price to the challenges in cultivation. These mushrooms cannot be cultivated commercially and grow in Himalayan conifer forests across temperate regions, and the foothills in Himachal Pradesh, Uttarakhand, and Jammu and Kashmir. And it takes months for villagers to collect enough of these mushrooms, dry them, and bring them to the market.

32. Which of the following have species that can establish symbiotic relationship with other organisms? [I.A.S. (Pre) 2021]

  1. Cnidarians
  2. Fungi
  3. Protozoa

Select the correct answer using the code given below.

Correct Answer: (d) 1, 2, and 3
Solution:Cnidaria is a phylum under Kingdom Animalia containing over 11,000 species of aquatic animals found both in freshwater and marine environments. Mostly marine animals, the cnidarians include the corals, hydras, jellyfish, Portuguese men-of-war, sea anemones, sea pens, sea whips, and sea fans. The symbiosis between cnidarians (e.g., corals or sea anemones) and intracellular dinoflagellate algae of the genus Symbiodinium is of immense ecological importance. In particular, this symbiosis promotes the growth and survival of coral reefs in nutrient-poor tropical waters; indeed, coral reefs could not exist without this symbiosis.
Fungi have several symbiotic (mutualistic) relationships with other organisms. In mutualism, both organisms benefit from the relationship. Two common mutualistic relationships involving fungi are mycorrhiza and lichen. Mycorrhiza are symbiotic relationships that form between fungi and vascular plants. The fungi colonize the root system of a host plant, providing increased water and nutrient absorption capabilities while the plant provides the fungus with carbohydrates formed from photosynthesis. A lichen is an organism that results from a mutualistic relationship between a fungus and a photosynthetic organism. The other organism is usually a cyanobacterium or green algae. The fungus grows around the bacterial or algal cells. The fungus benefits from the constant supply of food produced by the photosynthesizer. The photosynthesizer benefits from the water and nutrients absorbed by the fungus.
Symbiosis in protozoa mostly represents a close mutualistic association between a protozoan and unicellular symbionts (bacteria, cyanobacteria or/and unicellular algae) or protozoans and a multicellular organism (ruminants, lower termites, wood-eating cockroaches, plants).

33. Which one of the following is a useful functional association between fungi and the roots of higher plants? [I.A.S. (Pre) 1999]

Correct Answer: (d) Mycorrhiza
Solution:Cnidaria is a phylum under Kingdom Animalia containing over 11,000 species of aquatic animals found both in freshwater and marine environments. Mostly marine animals, the cnidarians include the corals, hydras, jellyfish, Portuguese men-of-war, sea anemones, sea pens, sea whips, and sea fans. The symbiosis between cnidarians (e.g., corals or sea anemones) and intracellular dinoflagellate algae of the genus Symbiodinium is of immense ecological importance. In particular, this symbiosis promotes the growth and survival of coral reefs in nutrient-poor tropical waters; indeed, coral reefs could not exist without this symbiosis.
Fungi have several symbiotic (mutualistic) relationships with other organisms. In mutualism, both organisms benefit from the relationship. Two common mutualistic relationships involving fungi are mycorrhiza and lichen. Mycorrhiza are symbiotic relationships that form between fungi and vascular plants. The fungi colonize the root system of a host plant, providing increased water and nutrient absorption capabilities while the plant provides the fungus with carbohydrates formed from photosynthesis. A lichen is an organism that results from a mutualistic relationship between a fungus and a photosynthetic organism. The other organism is usually a cyanobacterium or green algae. The fungus grows around the bacterial or algal cells. The fungus benefits from the constant supply of food produced by the photosynthesizer. The photosynthesizer benefits from the water and nutrients absorbed by the fungus.
Symbiosis in protozoa mostly represents a close mutualistic association between a protozoan and unicellular symbionts (bacteria, cyanobacteria or/and unicellular algae) or protozoans and a multicellular organism (ruminants, lower termites, wood-eating cockroaches, plants).

34. Lichens, which are capable of initiating ecological succession even on a bare rock, are actually a symbiotic association of — [I.A.S. (Pre) 2014]

Correct Answer: (b) Algae and fungi
Solution:Lichens are two organisms that grow together in a symbiotic relationship. Lichens are a partnership between fungi and algae. This partnership benefits both organisms; the algae photosynthesize, providing food for the fungus, while the fungus provides shelter and protection for the algae. While lichens are a well-known example of symbiosis, other organisms also exhibit symbiotic relationships with fungi, such as mycorrhizae, which form partnerships between fungi and plant roots.

35. 'Mycorrhiza' is a symbiotic association between: [U.P. B.E.O. (Pre) 2019]

Correct Answer: (c) Fungi and plants
Solution:Cnidaria is a phylum under Kingdom Animalia containing over 11,000 species of aquatic animals found both in freshwater and marine environments. Mostly marine animals, the cnidarians include the corals, hydras, jellyfish, Portuguese men-of-war, sea anemones, sea pens, sea whips, and sea fans. The symbiosis between cnidarians (e.g., corals or sea anemones) and intracellular dinoflagellate algae of the genus Symbiodinium is of immense ecological importance. In particular, this symbiosis promotes the growth and survival of coral reefs in nutrient-poor tropical waters; indeed, coral reefs could not exist without this symbiosis.
Fungi have several symbiotic (mutualistic) relationships with other organisms. In mutualism, both organisms benefit from the relationship. Two common mutualistic relationships involving fungi are mycorrhiza and lichen. Mycorrhiza are symbiotic relationships that form between fungi and vascular plants. The fungi colonize the root system of a host plant, providing increased water and nutrient absorption capabilities while the plant provides the fungus with carbohydrates formed from photosynthesis. A lichen is an organism that results from a mutualistic relationship between a fungus and a photosynthetic organism. The other organism is usually a cyanobacterium or green algae. The fungus grows around the bacterial or algal cells. The fungus benefits from the constant supply of food produced by the photosynthesizer. The photosynthesizer benefits from the water and nutrients absorbed by the fungus.
Symbiosis in protozoa mostly represents a close mutualistic association between a protozoan and unicellular symbionts (bacteria, cyanobacteria or/and unicellular algae) or protozoans and a multicellular organism (ruminants, lower termites, wood-eating cockroaches, plants).

36. Lichen are the complex creature, made from — [R.A.S./R.T.S. (Pre) 1997]

Correct Answer: (b) Fungi and Algae
Solution:Lichens are two organisms that grow together in a symbiotic relationship. Lichens are a partnership between fungi and algae. This partnership benefits both organisms; the algae photosynthesize, providing food for the fungus, while the fungus provides shelter and protection for the algae. While lichens are a well-known example of symbiosis, other organisms also exhibit symbiotic relationships with fungi, such as mycorrhizae, which form partnerships between fungi and plant roots.

37. The interaction between algae and fungi to form lichen is called : [65th B.P.S.C. (Pre) 2019]

Correct Answer: (b) Mutualism
Solution:The interaction between algae and fungi to form lichen is called mutualism. Symbiosis of algae and fungi in lichens is the mutually helpful symbiotic relationship between them. The algae or cyanobacteria (chlorophyll–containing partner) benefit their fungal partner by producing organic compounds through photosynthesis. In return, the fungal partner benefits from the algae or cyanobacteria by protecting them from the environment by its filaments, which also gather moisture and nutrients from the environment, and (usually) provide an anchor to it.

38. In lichen, a chlorophyll-containing partner lives together — [68th B.P.S.C. (Pre) 2022]

Correct Answer: (a) Algae and a fungus
Solution:The interaction between algae and fungi to form lichen is called mutualism. Symbiosis of algae and fungi in lichens is the mutually helpful symbiotic relationship between them. The algae or cyanobacteria (chlorophyll–containing partner) benefit their fungal partner by producing organic compounds through photosynthesis. In return, the fungal partner benefits from the algae or cyanobacteria by protecting them from the environment by its filaments, which also gather moisture and nutrients from the environment, and (usually) provide an anchor to it.

39. Which of the following do not grow in polluted area? [Rajasthan P.C.S. (Pre) 2013]

Correct Answer: (c) Lichen
Solution:Lichens usually grow in a wide range of environmental conditions. But they are quite sensitive to atmospheric pollutants like sulphur dioxide and nitrogen. To grow, lichens get their nutrients from the air. Because lichens have no roots or protective surface, they cannot filter what they absorb, so anything in the air is taken straight inside. If there are pollutants, it can accumulate in the lichen and can become toxic very quickly. Air pollution also leads to a decline in the lichen population and thus, they can be used as indicator organisms. As a rule of thumb, the smaller the size and less variety of lichens in the area, the more polluted is the environment.

40. Nitrogen fixing bacteria present in the nodules of the root of leguminous plant are : [Uttarakhand P.C.S. (Pre) 2007]

Correct Answer: (c) Symbiotic
Solution:Nitrogen fixing bacteria present in the nodules on the roots of the leguminous plant are symbiotic. During nitrogen fixation, bacteria such as Rhizobium japonicum convert nitrogen gas (N₂) into ammonium compounds (NH₄OH). These bacteria live in the roots of legumes including alfalfa, clover, peas, and beans. Some blue-green algae can also fix nitrogen.