Category 1
What role do soil microorganisms play in nutrient cycling in organic farming?
Soil microorganisms decompose organic matter and convert complex nutrients into simpler forms through processes like mineralization and nitrogen fixation, making nutrients available for plant uptake.
Rhizobium bacteria are primarily involved in which process?
B. Nitrogen Fixation
How do pollinators support organic farming?
Pollinators such as honeybees (Apis mellifera) and bumblebees (Bombus terrestris) transfer pollen between flowers, significantly increasing crop yields.
Which of the following is a free-living nitrogen-fixing bacterium?
C. Azotobacter chroococcum
Name three earthworm species important to organic farming.
Eisenia fetida (red wigglers), Lumbricus terrestris, and Eudrilus eugeniae are significant earthworm species that enhance soil structure and fertility.
The material created by decomposers that improves soil texture and water retention is called:
C. Humus
What is the role of mycorrhizal fungi in organic farming?
Mycorrhizal fungi, such as Glomus mosseae and Rhizophagus irregularis, form symbiotic relationships with plant roots, increasing water and mineral uptake, especially phosphorus, and enhancing plant growth.
Which insect is important for pollination in organic farming?
B. Honeybee
How do decomposers improve soil structure and fertility?
Decomposers like Trichoderma, Penicillium, Aspergillus, and bacteria such as Bacillus subtilis break down organic matter into humus, which improves soil texture, water retention, and long-term fertility.
Bacillus thuringiensis (Bt) is effective mainly against:
C. Caterpillars and mosquito larvae
What nutrients are released as decomposers break down organic materials?
Decomposers release nitrogen, phosphorus, sulfur, and micronutrients during the breakdown of plant residues, compost, and manure.
Ecological balance in organic farming helps reduce pest outbreaks because:
B. Natural predators keep pest populations in check
What are earthworm castings, and why are they beneficial?
Earthworm castings are nutrient-rich excretions containing nitrogen, phosphorus, calcium, and beneficial microbes by improving soil fertility and biological activity.
Which earthworm species is commonly known as the red wiggler?
C. Eisenia fetida
What makes Bacillus thuringiensis (Bt) an effective biological pest control agent?
Bt produces crystal proteins toxic to caterpillars, mosquito larvae, and other soft-bodied pests, while being harmless to humans, wildlife, and beneficial insects.