Food chains are very important for the survival of most species.

Food Web Example with Image - Teachoo.jpg

6.1 If 10,000 J solar energy falls on green plants in a terrestrial ecosystem, what percentage of solar energy will be converted into food energy? 

a) 10,000 J 

b) 100 J 

c) 1000 J 

d) It will depend on the type of the terrestrial plant. 

 

Answer

6.1 b) 100 J

Only 1% of the energy of sunlight that falls on leaves is convert into food energy by plants

If 10,000J is the energy of sunlight;

(1/100) x 10000 = 100J

 

Common mistake : Only 1% of energy from sunlight is converted to food energy. On the other hand, 10% of the energy flows from one trophic level to another

10 Percent Law-Teachoo-01.jpg

6.2 If Ravi is consuming curd/yogurt for lunch , which trophic level in a food chain should he be considered as occupying ? 

a) First trophic level 

b) Second trophic level 

c) Third trophic level 

d) Fourth trophic level 

Answer

6.2 c) Third Trophic leve

Curd is made from milk which is obtained from cow

Cow is a primary consumer that feeds on producer (grass) and occupies the second trophic level

Consuming the produce obtained from an organism at second trophic level makes Ravi belong to the third trophic level

Trophic levels refer to the position an organism occupies in a food chain-Teachoo-01.jpg

 

6.3 The decomposers are not included in the food chain.The correct reason for the same is because decomposers: 

  • Act at every trophic level of the food chain 

  • Do not breakdown organic compounds 

  • Convert organic material to inorganic forms 

  • Release enzymes outside their body to convert organic material to inorganic forms 

Answer

 

6.3 a) Act at every trophic level of the food chain 

 

Thus, they do not belong to any particular trophic level

6.4 Matter and energy are two fundamental inputs of an ecosystem. Movement of 

a) Energy is bidirectional and matter is repeatedly circulating. 

b) Energy is in repeated circulation and matter is unidirectional. 

c) Energy is unidirectional and matter is repeatedly circulating. 

d) Energy is multidirectional and matter is bidirectional. 

 

Answer

6.4 c) Energy is unidirectional and matter is repeatedly circulating 

10 Percent Law-Teachoo-01.jpg

6.5 Which of the following limits the number of trophic levels in a food chain? 

a) Decrease in energy at higher trophic levels 

b) Less availability of food 

c) Polluted air 

d) Water



Answer

 

6.5 a) Decrease in energy at higher trophic level  

The energy keeps on decreasing in each trophic level

This decrease is due to the heat released

As a result, the number of trophic levels is limited 

  1. Class 10
  2. Chapter 15 Class 10 - Our Environment (Term 2)
Class 10
Chapter 15 Class 10 - Our Environment (Term 2)

About the Author

CA Maninder Singh's photo - Founder at Teachoo
CA Maninder Singh
CA Maninder Singh is a Chartered Accountant for the past 11 years and a teacher from the past 11 years. He teaches Science, Accounts and English at Teachoo