Zigya Logo

Chapter Chosen

Organisms and Populations

Book Chosen

Biology

Subject Chosen

Biology

Book Store

Download books and chapters from book store.
Currently only available for.
CBSE Gujarat Board Haryana Board

Previous Year Papers

Download the PDF Question Papers Free for off line practice and view the Solutions online.
Currently only available for.
Class 10 Class 12

Consider the following statements concerning food chains
A) removal of 80% tigers from an area resulted in greatly increased growth of vegetation
B) removal of most of the carnivores resulted in an increased population of deers
C) length of food chains is generally limited to 3-4 trophic levels due to energy loss
D) the length of food chains may vary from 2 to 8 trophic level
Which two of the above statements are correct? 

  • B and C

  • C and D

  • A and D

  • A and B


A.

B and C

The series of organisms eating one and being eaten by other is called food chain. A simple food chain consists of producers, herbivores and carnivores. The length of the food chain is generally limited to 3-4 trophic levels due to energy loss. In grazing food chain the producers (ie, plants) are eaten by herbivores are eaten by carnivores. Therefore, the removal of most of the carnivores resulted in an increased population of deer.

The series of organisms eating one and being eaten by other is called food chain. A simple food chain consists of producers, herbivores and carnivores. The length of the food chain is generally limited to 3-4 trophic levels due to energy loss. In grazing food chain the producers (ie, plants) are eaten by herbivores are eaten by carnivores. Therefore, the removal of most of the carnivores resulted in an increased population of deer.


Population density is denoted by the symbol
  • N
  • D
  • M
  • D

A.

N

The number of births during a given period in the
population that are added to the initial density is 

 :
  • Natality
  • Mortality
  • Migration
  • Immigration

A.

Natality

To live in groups is beneficial because :
  • feeling of security
  • can obtain food easily
  • Partner is available for mating
  • All the above

D.

All the above

The departure of a individual from a population is called :
  • Natality 
  • Mortality
  • Immigration 
  • Emigration

D.

Emigration

Ants give information to their companions :
  • by dancing
  • by secretion of pheromones
  • by making sound
  • by defecating

B.

by secretion of pheromones