Ecology is basically concerned with four levels of biological organization, which one of the following is
correct representation?

1. Population $\to$ Ecosystem $\to$ Biome $\to$ Landscape.

2. Communities $\to$ Population $\to$ Ecosystem $\to$ Biome.

3. Organisms $\to$ Population $\to$ Communities $\to$ Biome.

4. Species $\to$ Ecosystem $\to$ Communities $\to$ Biome.

The type of population interaction exhibited by visiting flamingos and resident fishes in South American Lakes, is also shown by

1. Sparrow eating any seed.

2. Cuckoo and crow.

3. Abingdon tortoise and goats in Galapagos island.

4. Sea anemone and clown fish.

Natality refers to:
1. Death rate
2. Birth rate
3. Number of individuals leaving the habitat
4. Number of individuals entering the habitat

According to Darwin, organic evolution is due to:

What type of human population is represented by the following age pyramid? 

  
1.  Stable population
2.  Declining population
3.  Expanding population
4.  Vanishing population