★ NEW Preorder Ancient and Medieval Indian History ⚡️ Shipping from Aug 15^th ★ ★ NEW Prelims Cracker 2027 ⚡️ New Subjects from Sep 1^st 📞 Call Now: 9211591415 ★ ★ NEW GS Foundation 2027 ⚡️ Just Started ⬇️ Download Brochure 📞 Call Now: 9211591415 ★ ★ PMF IAS Impact 🎯 53 Direct Hits in Prelims 2025 and 🎯 46 Direct Hits in Prelims 2026 ★

★ NEW Preorder Ancient and Medieval Indian History ⚡️ Shipping from Aug 15^th ★ ★ NEW Prelims Cracker 2027 ⚡️ New Subjects from Sep 1^st 📞 Call Now: 9211591415 ★ ★ NEW GS Foundation 2027 ⚡️ Just Started ⬇️ Download Brochure 📞 Call Now: 9211591415 ★ ★ PMF IAS Impact 🎯 53 Direct Hits in Prelims 2025 and 🎯 46 Direct Hits in Prelims 2026 ★

Cyanobacteria

Primary producers in ocean food chains — UPSC Prelims PYQ 2021

Jeevan Bisht
2021 / Environment / Environment Basics / UPSC Prelims PYQs
Cyanobacteria / Diatoms / Marine Food Chains / Phytoplankton / Primary Producers

Organisms used as biofertilisers — UPSC Prelims PYQ 2013

Jeevan Bisht
2013 / Agriculture / Determinants / Geography / UPSC Prelims PYQs
Biofertilizers / Cyanobacteria / Microorganisms / Nitrogen Fixation / Nostoc

UPSC Prelims PYQ 2010: Feature of blue-green algae that promotes them as bio-fertilizers

UPSC Prelims PYQ 2000: Biofertilizer organisms suitable for rice crop

PMF IAS
2000 / Agriculture / Determinants / Geography / UPSC Prelims PYQs
Biofertilizers / Blue-Green Algae / Cyanobacteria / Nitrogen Fixation / Rice Cultivation

Stromatolites

What are Stromatolites?