Which of the following is correctly matched

Options

A. Stratification - Population
B. Aerenchyma - Opuntia
C. Age pyramid - Biome
D. Parthenium - 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. **Option 1: Stratification and Population**
- Stratification refers to the vertical distribution of different layers in an ecosystem, particularly in forests and aquatic environments. It involves the arrangement of plants in layers (e.g., herbs, shrubs, medium-sized trees, and tall trees).
- **Conclusion**: This option is incorrectly matched because stratification is not related to population.

2. **Option 2: Arenchyma and Apunctia**
- Arenchyma is a type of plant tissue that contains air cavities, which help in buoyancy for plants with floating leaves. Apunctia, however, does not have arenchyma.
- **Conclusion**: This option is also incorrectly matched since apunctia does not contain arenchyma.

3. **Option 3: Age Pyramid and Biome**
- An age pyramid represents the distribution of various age groups in a population, indicating the number of individuals in pre-reproductive, reproductive, and post-reproductive stages. It is a demographic tool and is associated with populations, not biomes.
- **Conclusion**: This option is incorrectly matched because age pyramids are related to population dynamics, not biomes.

4. **Option 4: Parthenium and Threat to Biodiversity**
- Parthenium is an invasive weed that poses a significant threat to biodiversity. It was introduced to India as a contaminant in imported wheat and has spread widely, outcompeting native species and leading to their decline.
- **Conclusion**: This option is correctly matched as Parthenium is indeed a threat to biodiversity.

### Final Answer:
The correctly matched option is **Option 4: Parthenium is a threat to biodiversity**.

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