Question : The green plants in a terrestrial ecosystem capture about ______ per cent of the energy of sunlight that falls on their leaves and convert it into food energy.

Option 1: 20

Option 2: 10

Option 3: 1

Option 4: 5

Question : Yellow spots on citrus leaves is due to deficiency of:

Option 1: Zinc

Option 2: Magnesium

Option 3: Boron

Option 4: Iron

Question : The deciduous trees will :

Option 1: shed their leaves every year

Option 2: not lose their leaves

Option 3: synthesise their own food

Option 4: depend on others for their food

Question : "Red Data Book" provides an account of:

Option 1: Endangered plants only

Option 2: Fossil plants

Option 3: Endangered plants and animals

Option 4: Extinct animals only

Question : The surface tension of water on adding detergent to it:

Option 1: increases

Option 2: decreases

Option 3: no change

Option 4: becomes zero