IB Biology Topic C4.1: Populations and Communities Questionbank

A bacterium and fungus co-occur less than expected (χ² p=0.02). Which combination supports antibiotic-mediated competition at 5% significance?

Culture P received water, mineral ions and CO₂ but no organic carbon. Which conclusion is supported?

Wait longer before recapture so marked beetles mix.

Set more traps near R to recapture marked beetles.

Restrict the estimate to the area around R.

Recapture sooner before marked beetles move from R.

Both are underestimated; X exceeds Y by about 7.

Only Y is overestimated; X exceeds Y by about 4.

Both are overestimated; X exceeds Y by about 7.

Only X is overestimated; X exceeds Y by about 4.

Significant negative association; nutrient restoration removes bacterial inhibition by fungal filtrate.

Significant negative association; fresh medium at the fungus’s pH inhibits bacteria.

Significant negative association; pH-matched, nutrient-restored fungal filtrate inhibits bacteria.

No significant association; pH-matched, nutrient-restored fungal filtrate inhibits bacteria.

Respiration exceeds gross photosynthesis in light; respiration causes dark biomass loss

Gross photosynthesis exceeds respiration in light; respiration causes dark biomass loss

Gross photosynthesis exceeds respiration in light; photosynthesis causes dark biomass loss

Respiration exceeds gross photosynthesis in light; photosynthesis causes dark biomass loss