DP Biology (first assessment 2025)

Question SPM.1A.SL.TZ0.28

Date	May Specimen-2023	Marks available	[Maximum mark: 1]	Reference code	SPM.1A.SL.TZ0.28
Level	SL	Paper	1A	Time zone	TZ0
Command term		Question number	28	Adapted from	N/A

28.

[Maximum mark: 1]

SPM.1A.SL.TZ0.28

Black walnut (Juglans nigra) secretes the chemical juglone into the soil surrounding its roots. Juglone inhibits cell respiration in other species of plants. What does this example illustrate?

A. Mutualism

B. Intraspecific competition

C. Allelopathy

D. Parasitism

[1]

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Syllabus sections

C. Interaction and interdependence

C. Interaction and interdependence » C4.1. Populations and communities » C4.1.6. Negative feedback control of population size by density-dependent factors

C. Interaction and interdependence » C4.1. Populations and communities » C4.1.12. Mutualism as an interspecific relationship that benefits both species

C. Interaction and interdependence » C4.1. Populations and communities

Question SPM.1A.SL.TZ0.28

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