CBSE Class 12-science Answered
(a) Biopesticides are biological control agents and their products are used to control pests like weeds, insects and pathogens. Bioherbicides like Dalpon are used to control broad-leaved weeds of cereal crops and Baculoviruses are bioinsecticidal viral pathogens that kill insects and other arthropods.
(b) The symbiotic association of fungi and roots of higher plants is called mycorrhiza. The fungal hyphae increase the absorptive surface of roots which facilitates better intake of nutrients such as nitrogen, phosphorus, calcium etc., assist in absorption of water, carry out solubilisation of complex organic molecules into simple inorganic nutrients, their absorption and transfer to roots, offer protection to the plants from the attack of disease-causing pathogens by secreting antimicrobial substances and provide tolerance to salinity and drought.