Between which of the following, the relationship is not an example of commensalism?

1. Orchid and the tree on which it grows

2. Cattle Egret and grazing cattle

3. Sea Anemone and Clownfish

4. Female wasp and fig species

Carnivorous animals - lions and leopards, occupy the same niche but lions predate mostly larger animals and leopards take smaller ones. This mechanism of competition is referred to as-

1. Character displacement

2. Altruism

3. Resource partitioning

4. Competitive exclusion

The formula for exponential population growth is :

1. dt/dN= rN

2. dN/rN= dt

3. rN/dN= dt

4. dN/dt= rN

Geometric representation of age structure is a characteristic of:

1. Biotic community

2. Population

3. Lanscape

4. Ecosystem

A country with a high rate of population growth took measures to reduce it. The figure below shows age-sex pyramids of populations. A and B are twenty years apart. Select the correct interpretation about them: 
 
Interpretations

The figure given below is a diagrammatic representation of the response of organisms to abiotic factors. What do (a), (b) and (c) represent, respectively? 
   

Study the four statements (a–d) given below and select the two correct ones out of them –
a. A lion eating a deer and a sparrow feeding on grain are ecologically similar in being consumers
b. Predator star fish Pisaster helps in maintaining species diversity of some invertebrates
c. Predators ultimately lead to the extinction of prey species
d. Production of chemicals such as nicotine, strychnine by the plants are metaboilic disorders
The two correct stament are-
1. a and d
2. a and b
3. b and c
4. c and d

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

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