Ecology and Environment
- Which of the following would appear as the pioneer organisms on bare rocks ? Answer: 1. Lichens On bare rock, lichens are the pioneer species of primary succession. They secrete acids, weather the rock and form soil,... 1
- When does the growth rate of a population following the logistic model equal zero ? The logistic model is given as dN/dt = rN(1-N/K) : Answer: 1. when N/K is exactly one. Logistic growth: dN/dt=rN(1-N/K) . The growth rate is zero when 1-N/K=0 , that is when N/K=1 exactly (N... 1
- Which of the following is the most important cause of animals and plants being driven to extinction ? Answer: 3. Habitat loss and fragmentation Key idea: The most important cause of species extinction is habitat loss and fragmentation. Over-e... 1
- Which is the National Aquatic Animal of India ? Answer: 2. River dolphin Key idea: The river dolphin (Gangetic dolphin, Platanista gangetica) is India's National Aquatic Animal, declared i... 1
- Joint Forest Management Concept was introduced in India during : Answer: 3. 1980s Key idea: Joint Forest Management (JFM) was introduced in India in 1980s. It involves local communities in protecting and m... 1
- Which one of the following is a characteristic feature of cropland ecosystem ? Answer: 2. Least genetic diversity Key idea: A cropland is a managed ecosystem where people grow one or a few crop species. This gives the l... 1
- Gause's principle of competitive exclusion states that : Answer: 3. No two species can occupy the same niche indefinitely for the same limiting resources. Key idea: Gause's principle says that two... 1