Ecosystem - Online Test
Q1. Humus will never be
Answer : Option B
Explaination / Solution:
Humification leads to accumulation of dark coloured amorphous substance called humus that is highly resistance to microbial action and decompose at very slow rate.
Q2. Which one of the following is the most important service provided by ecosystems:
Answer : Option C
Explaination / Solution:
Ecosystem services includes all activities performed by nature to benefits of human beings. The most important ecological service includes soil formation. Soil is essential for growth of plants that provide food to all living forms.
Q3. The product of ecosystem processes are called as
Answer : Option A
Explaination / Solution:
The products of ecosystem processes are called as ecosystem services. Ecosystem services includes purification of air and water by forests and soil formation as well as nutrient cycles
Q4. The value of ecosystem services of biodiversity is
Answer : Option D
Explaination / Solution:
The value of ecosystem services of biodiversity is difficult to determine as it includes services like cultural and spiritual value along with life saving services for all organisms.
Q5. Which of the following ecosystem services cost maximum
Answer : Option A
Explaination / Solution:
Soil formation accounts for about 50% of total cost of ecosystem services. Nutrient cycling and recreation accounts for about 10% of all ecosystem services.
Q6. The scientist who put price tag of US$ 33 trillion a year for nature’s life-support services was
Answer : Option C
Explaination / Solution:
Robert Costanza is the director and founder of the Gund Institute for Ecological Economics at the University of Vermont, and cofounder of the International Society for Ecological Economics.
In 1997, Costanza and his colleagues made news headlines around the world with a paper, published in the British journal Nature, that estimated the annual net worth of the biosphere: $33 trillion, a figure greater than the annual gross national products (GNP) of all the world’s economies combined.
Q7. Forests controls drought through
Answer : Option B
Explaination / Solution:
The volume of water retained by forests can depend on characteristics such as forest cover area, the length of vegetation growing season, tree composition and tree density, as well as the age and the number of layers of vegetation cover. Water retention by forests affects the amount and timing of the water delivered to streams and groundwater by increasing and maintaining infiltration and storage capacity of the soil. Forests can soak up excess rainwater, preventing run-offs and damage from flooding. By releasing water in the dry season, forests can also help provide clean water and mitigate the effects of droughts. Drought is due to less rainfall.
Q8. Universal non-polluting source of energy is
Answer : Option A
Explaination / Solution:
Universal non-polluting source of energy is sun. All the sources of energy are directly and indirectly derived from sun including fossil fuels.
Q9. Earth crust is the reservoir of sedimentary type of nutrients like
Answer : Option A
Explaination / Solution:
Earth crust is the reservoir of sedimentary type of nutrients like phosphorus. Atmosphere is the reservoir of gaseous types of cycle like oxygen and nitrogen along with carbon.
Q10. Fundamental ecosystem services are taken as granted because
Answer : Option A
Explaination / Solution:
Researchers have put an average price tag of US $33 trillion a year on these fundamental ecosystems services, which is largely taken for granted because they are free. This service includes nature’s life support system without which life is not possible on this planet.
