Read the following passage carefully and answer the given questions.
Biofertilisers
Biofertilisers are organisms that enrich the nutrient quality of the soil and their main sources are bacteria, fungi and cyanobacteria. You have studied about the nodules on the roots of leguminous plants formed by the symbiotic association of Rhizobium. These bacteria can fix atmospheric nitrogen into organic forms. Other bacteria can also fix atmospheric nitrogen while free-living in the soil (examples Azospirillum and Azotobacter). Fungi are also known to form symbiotic associations with plants (mycorrhiza). Many members of the genus Glomus form mycorrhiza. Plants having such associations show other benefits also, such as resistance to root-borne pathogens, tolerance to salinity and drought, and an overall increase in plant growth and development. Cyanobacteria are autotrophic microbes widely distributed in aquatic and terrestrial environments many of which can fix atmospheric nitrogen, e.g. Anabaena, Nostoc, Oscillatoria, etc. In paddy fields, cyanobacteria serve as an important biofertiliser. Blue green algae also add organic matter in to the soil and increase its fertility. Currently, in our country, a number of biofertilisers are available commercially in the market and farmers use these regularly in their fields to replenish soil nutrients and to reduce dependence on chemical fertilisers.
Resistance to root-borne pathogens, salinity and drought tolerance are introduced into which type of plants?
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → Plants having symbiotic relations with fungi
Option (1) Xerophytic plants — Incorrect. Xerophytes are plants of dry places, such as cacti. They bear drought through their own body features, like a thick cuticle and fewer stomata. The benefits named in the question come from a fungal partner, not from being a xerophyte.
Option (2) Terrestrial plants — Incorrect. Terrestrial plants are all the plants that grow on land. Not every land plant gets these benefits; only those with a fungal partner in their roots do.
Option (3) Plants having symbiotic relations with fungi — Correct. This association of a fungus with plant roots is called mycorrhiza. The fungus absorbs phosphorus from the soil and passes it to the plant. Such plants also show resistance to root-borne pathogens and tolerance to salinity and drought.
Option (4) Non-legume plants — Incorrect. Non-legumes are plants that do not form root nodules with Rhizobium. This tells us nothing about a fungal partner. The benefits depend on mycorrhiza, which legumes and non-legumes can both form.
Note: The passage is taken from NCERT. NTA has put lines of the NCERT text together to make it. Most CUET (UG) questions come straight from NCERT, so study the book line by line, including figures and their titles.