Chapter 11 Solutions — Organisms and Populations

Chapter-end Exercises

1. 1.
   List the attributes that populations possess but not individuals.
2. 2.
   If a population growing exponentially double in size in 3 years, what is the intrinsic rate of increase (r) of the population?
3. 3.
   Name important defence mechanisms in plants against herbivory.
4. 4.
   An orchid plant is growing on the branch of mango tree. How do you describe this interaction between the orchid and the mango tree?
5. 5.
   What is the ecological principle behind the biological control method of managing with pest insects?
6. 6.
   Define population and community.
7. 7.
   Define the following terms and give one example for each:

   • (a) Commensalism
   • (b) Parasitism
   • (c) Camouflage
   • (d) Mutualism
   • (e) Interspecific competition
8. 8.
   With the help of suitable diagram describe the logistic population growth curve.
9. 9.
   Select the statement which explains best parasitism.

   • (a) One organism is benefited.
   • (b) Both the organisms are benefited.
   • (c) One organism is benefited, other is not affected.
   • (d) One organism is benefited, other is affected.
10. 10.
    List any three important characteristics of a population and explain.