Which of the following is correctly matched?

Options

A. Stratification-Population
B. Aerenchyma-Opuntia
C. Age pyramid-Biome
D. Parthenium hysterophorus–Threat to biodiversity

Answer

To determine which of the following options is correctly matched, we will analyze each option one by one.

### Step-by-Step Solution:

1. **Analyze Option A: Population with Stratification**
- Stratification refers to the vertical distribution of different species in an ecosystem, not within a single population. A population consists of individuals of the same species, and there is no vertical distribution within it. Therefore, this combination is incorrect.

2. **Analyze Option B: Aerenchyma with Opuntia**
- Aerenchyma is a specialized tissue found in aquatic plants that contains air cavities to provide buoyancy. Opuntia, on the other hand, is a xerophyte, which thrives in dry environments. Since aerenchyma is not found in xerophytes, this combination is also incorrect.

3. **Analyze Option C: Age Pyramid with Biome**
- An age pyramid represents the age distribution of individuals within a single population, showing how many individuals belong to different age groups. A biome, however, encompasses multiple populations of different species. Therefore, it is not appropriate to create an age pyramid for an entire biome. This combination is incorrect as well.

4. **Analyze Option D: Parthenium hysterophorus as a Threat to Biodiversity**
- Parthenium hysterophorus, commonly known as carrot grass, is an alien species that has invaded India and poses a significant threat to local biodiversity. It competes with native species, leading to their decline. This combination accurately reflects the impact of Parthenium on biodiversity, making it the correct match.

### Conclusion:
The correctly matched option is **D: Parthenium hysterophorus is a threat to biodiversity**.

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