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1.4 Species Interactions — Test 2
Q1. A (+ −) type of interaction, where one species benefits and the other is harmed, is seen in:✓ Predation and parasitism
Q2. When one organism produces organic matter of no use to itself, while another organism uses it and depends on it, the interaction is:✓ Commensalism
Q3. If '+' is beneficial and '0' is no effect, commensalism is designated as:✓ + 0
Q4. Gause's competitive exclusion principle applies to:✓ Interspecific competition
Q5. An example of commensalism is:✓ An orchid growing on the trunk of a mango tree
Q6. The main function of mycorrhiza for the plant is:✓ Absorption of phosphates
Q7. Cattle egrets follow grazing cattle, catching insects that the cattle disturb. This interaction is an example of:✓ Commensalism
Q8. Mycorrhizal cost-benefit analyses show that when soil nutrients (e.g. phosphate) are very high, the plant-fungus association can shift towards:✓ Parasitism
Q9. The functional response of a predator refers to:✓ The number of prey attacked per predator as a function of prey density
Q10. For long-term biological control, the most desirable prey-predator (or host-parasite) relationship has:✓ High host specificity and moderate virulence
Q11. According to the plant vigour hypothesis, herbivores prefer to attack:✓ Fast-growing, vigorous plants
Q12. The relative success of green plants despite herbivory is best explained by which combination: (B) herbivore densities kept low by predators; (C) plants secrete herbivore-deterrent chemicals?✓ B and C
Q13. In the Lotka-Volterra competition model, stable coexistence of two species requires that:✓ Intraspecific competition exceeds interspecific for each species
Q14. In the Lotka-Volterra competition model, a competition coefficient α12 < 1 means that:✓ Individuals of species 2 inhibit species 1 less than species 1 inhibits its own members
Q15. In a Lotka-Volterra competition with species A (K_A = 150) and species B (K_B = 200), competition coefficients α = 1 and β = 1.3, the predicted outcome is that:✓ Species B wins
Q16. The profitability of a prey item for a predator depends on its energy content and:✓ The handling (foraging) time required
Q17. A tree species that secretes an allelochemical preventing the growth of its own seedlings nearby is likely to show which dispersion pattern in the adult population?✓ Uniform (regular)
Q18. Given that all organisms can host parasites, a single host can carry several parasites, and many parasites are host-specific, it follows that:✓ There are more parasite species than host species
Q19. A red, tubular, odourless flower is most likely pollinated by:✓ Birds
Q20. Match each interaction with its fitness-effect sign (species 1 / species 2) and select the correct option.✓ A-ii, B-i, C-iv, D-iii