Question

Assertion: Allelopathy is a form of ammensalism that occurs in plants.
Reason: Association of rooting plants with fungal hyphae is an important example of Ammensalism.
A. Both Assertion and Reason are correct and Reason is the correct explanation for the Assertion.
B. Both Assertion and Reason are correct and Reason is not the correct explanation for the Assertion.
C. Assertion is correct but Reason is incorrect.
D. Both Assertion and Reason are incorrect.

Answer 1

Ammensalism is an antagonistic interspecific interaction in which one species is inhibited while other species is neither benefited or harmed. The species which is inhibited is called amnesal while the other one is called inhibitor.

Complete answer:
In ammensalism, inhibition is achieved through the secretion of certain chemicals called allochemics or allopathic substances.
The most common phenomenon of antibiosis is formation of antibiotics that are antagonistic to the microbes, e.g. Penicillium notatum releases penicillin to inhibit the growth of a variety of bacteria especially Staphylococcus bacterium. Similarly another mould Streptomyces griseus produces streptomycin antibiotic which inhibits the growth of many kinds of bacteria.
Trichoderma inhibits the growth of fungus Aspergillus.
Barley, sorghum, and sunflower crops are called smoother crops as these crops inhibit the growth of weeds.
Roots and hulls of Black walnut ‘Juglans nigra produce a chemical called Juglone which inhibits the growth of seedlings of Apple, tomato, and Alfalfa within its root zone.
Tagetes i.e. marigold secretes all chemicals toxic to soil nematodes and fungi.
Mycorrhizae represents the mutualistic relationship between the hyphae of a fungus and roots of about 80% of higher plants. The roots provide energy-yielding carbohydrates and shelter to the fungus while the latter helps in the absorption of water, minerals, etc. and produce growth promoting chemicals and secrete antibiotics to provide protection from pathogenic organisms. Hence the Assertion is correct but Reason is incorrect.
So, the correct answer is “Option c”.

Note:
Mutualistic interaction is a kind of positive interspecific interaction in which members of two different species favor the growth and survival of each other and their association is obligatory. So mutualism is a functional association.