Ecosystem

Which of the following representations shows the pyramid of numbers in a forest ecosystem? [figure]

1. B
2. A
3. D
4. C

Which one of the following is one of the characteristics of a biological community?

1. Mortality
2. Sex-ratio
3. Stratification
4. Natality

The biomass available for consumption by the herbivores and the decomposers is called –

1. Standing crop
2. Net primary productivity
3. Gross primary productivity
4. Secondary productivity

The correct sequence of plants in hydrosere is :

1. Volvox Hydrilla Pistia Scirpus Lantana Oak
2. Pistia Volvox Scirpus Hydrilla Oak Lantana
3. Oak Lantana Volvox Hydrilla Pistia Scirpus
4. Oak Lantana Scirpus Pistia Hydrilla Volvox

Which one of the following types of organisms occupy more than one trophic level in a pond ecosystem?

1. Phytoplankton
2. Zooplankton
3. Frog
4. Fish

Consider the following statements concerning food chains: (i) Removal of 80% tigers from an area resulted in greatly increased growth of vegetation (ii) Removal of most of the carnivores resulted in an increased population of deer (iii) The length of food chains is generally limited to 3-4 trophic levels due to energy loss (iv) The length of food chains may vary from 2 to 8 trophic levels Which two of the above statements are correct?

1. (iii), (iv)
2. (ii), (iii)
3. (i), (iv)
4. (i), (ii)

The slow rate of decomposition of fallen logs in nature is due to their:

1. low moisture content
2. poor nitrogen content
3. anaerobic environment around them
4. low cellulose content

About 70% of total global carbon is found in:

1. Grasslands
2. Agroecosystems
3. Oceans
4. Forests

Which one of the following ecosystem types has the highest annual net primary productivity ?

1. Temperate evergreen forest
2. Temperate deciduous forest
3. Tropical rain forest
4. Tropical deciduous forest

Which one of the following is not used for construction of ecological pyramids ?

1. Rate of energy flow
2. Dry weight
3. Fresh weight
4. Number of individuals