The IUCN Red List is based on a set of criteria to evaluate species vulnerability to extinction. Which one or more of the options is/are used as criteria?
Show Hint
- Absolute population size
- Geographic range
- Economic value
- Change in population size over time
The Correct Option is A, B, D
Solution and Explanation
Plant–Mycorrhizal Fungi Interactions
Step 1: Recall what mycorrhizae do.
Mycorrhizal fungi exchange soil nutrients (P, N, water) for photosynthate (carbon) from plant roots. The net effect depends on soil nutrient availability.
Step 2: Classify interactions by cost–benefit to the plant.
- Nutrient-poor soils: Fungal hyphae enhance nutrient uptake. Plant gains more than it pays in carbon. \(\Rightarrow\) Mutualism → (C) true.
- Nutrient-rich soils: Plant can acquire nutrients without fungus; fungus still takes carbon. Plant pays cost with little or no return. \(\Rightarrow\) Parasitism → (A) true.
- Intermediate/neutral cases: Net plant effect ≈ 0 while fungus still gains carbon. \(\Rightarrow\) Commensalism → (D) can occur.
Step 3: Eliminate the incorrect option.
(B) Predation involves killing or consuming another organism; mycorrhizal colonization does not fit this definition.
Final Answer: \[ \boxed{\text{(A) Parasitism, \quad (C) Mutualism, \quad (D) Commensalism}} \]
Top Questions on Ecology
- Why is the Amazon rainforest called the "lungs of the earth"?
An ornamental shrub species was brought from Japan in the early 1800s to India, where it was planted frequently in gardens and parks. The species persisted for many decades without spreading, and then began to spread invasively fifty years ago. Which one or more of the following processes could have led to it becoming invasive?
- One hypothesis for why the tropics have far greater species richness than higher latitudes is that the tropics are relatively aseasonal. Low seasonality can encourage high species richness through which one or more of the following mechanisms?
- In conservation biology, which one or more of the following is/are used to calculate the effective population size, $N_e$?
- Choose the correct statement.
Questions Asked in GATE EY exam
- During the process of succession in a community, species that are good colonisers are gradually replaced by species that are good competitors. Which one or more of the following statements is/are consistent with this pattern?
- GATE EY - 2026
- Ecological Succession
- Observations of algal species showed that their diversity was higher in pools where there were grazing snails compared to pools without snails. Which one of the following statements best explains this result?
- GATE EY - 2026
- Species-Area Relationships
Which one or more of the following is/are greenhouse gas(es)?
- GATE EY - 2026
- Ecology and Climate Change
- You are a plant ecologist studying a plant in the genus Veronica. You notice that, at open rocky sites, Veronica grows as a creeper spreading low to the ground, whereas in grasslands, the stem stands upright. You collect seeds from multiple populations in each habitat type and grow them under uniform conditions in a greenhouse. You find that all the plants grown in the greenhouse have stems that stand upright. Which one or more of the following explanations best support(s) your observations?
- GATE EY - 2026
- Evolution and Adaptation
- Honey bees are haplodiploid, which means that the relatedness is, on average, expected to be 0.75 between
- GATE EY - 2026
- Social Evolution