MCQ
Keystone species in an ecosystem are those which.
- AAre present in maximum number.
- BAre most frequent.
- CAttain a large biomass.
- DContribute to ecosystem properties.
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| Column $I$ | Column $II$ |
| ($a$) Dragonflies | ($i$) Biocontrol agents of several plant pathogens |
| ($b$) Bacillus | ($ii$) Get rid of Aphids thuringiensis and mosquitoes |
| ($c$) Glomus | ($iii$) Narrow spectrum insecticidal applications |
| ($d$) Baculoviruses | ($iv$) Biocontrol agents of lepidoteran plant pests |
| ($v$) Absorb phosphorus from soil |