Home
Class 12
BIOLOGY
In an area where DDT had been used exten...

In an area where DDT had been used extensively, the population of birds declined significantly because

A

birds stopped laying eggs

B

earth worms in the area got eradicated

C

cobras were feeding exclusively on birds

D

many of the birds laid, did not hatch

Text Solution

Verified by Experts

Promotional Banner

Topper's Solved these Questions

  • BIOLOGY AND HUMAN WELFARE

    SARAS PUBLICATION|Exercise EXAMPLE|86 Videos

  • CHROMOSOMAL BASIS OF INHERITANCE

    SARAS PUBLICATION|Exercise EXAMPLE|75 Videos

Similar Questions

Explore conceptually related problems

A lake near a village suffered heavy mortality of fishes within a few days. Consider the following reasons for this? a) Lots of urea and phosphate fertilizer were used in the crops in the vicinity b) The area was sprayed with DDT by an aircraft c) The lake water turned green and stinky d)Phvtoplankton populations in the lake declined initially thereby greatly reducing photosynthesis Which two of the above were the main causes of fish mortality in this lake?

List the areas where GPS is currently under use.

The concentration of polychlorinated biphenyls (PCB, an organochloride contaminant) in many fish population has been declining, since a ban on their production was instituted in the late 1970s. PCBs remain a potential problem, however, because they are lipophilic and are know to biomagnify. Based on this knowledge, what type of fish is expected to be safest for human consumption ?

Mention any four areas where DNA fingerprinting can be used.

A wire of length 18 m had been tied with electric pole at an angle of elevation 30^(@) with the ground. Because it was covering a long distance, it was cut and tied at an angle of elevation 60^(@) with the ground. How much length of the wire was cut?

Pick out the correct option from (a) to (e).I. Primary succession begins in areas where natural communities have been destroyed.II. Hydrarch succession takes place in water.III. The climax communityis the community that is in near equilibrium with the immediate environment.IV. Newly cooled lava secondary succession.

Consider the following four measures (a-d) that could br taken to successfully grow chickpea in an area where bacterial blight disease is common:Spray with Bordeaux mixture,Control of the insect vector of the disease pathogen,Use of only disease - free seeds

Palanikumar is a Lawyer. He lives in a costly flat. Due to high rent, he wants to shift his residence to a place where he has a chemical industry nearby. There the rent is very cheap and the area is less populated also. Rajasekar, his son studying VIII does not like this and likes to go to some other place. (a) Is Rajasekar right in his attitude?

SARAS PUBLICATION-BIOTECHNOLOGY AND ITS APPLICATIONS-EXAMPLE
  1. Which one of the following shows maximum, genetic diversity in India?

    Text Solution

    |

  2. Given below is a sample of a portion of DNA strand giving the base seq...

    Text Solution

    |

  3. In an area where DDT had been used extensively, the population of bird...

    Text Solution

    |

  4. Pheretima and its close relatives derive nourishment from

    Text Solution

    |

  5. PCR and Restriction Fragment Length Polymorphism are the methods for:

    Text Solution

    |

  6. Consumption of which one of the following foods can prevent the kind o...

    Text Solution

    |

  7. A patient brought to a hospital with myocardiaI infarction is normally...

    Text Solution

    |

  8. Which of the following statements are true regarding DNA polymerase us...

    Text Solution

    |

  9. If one strand of DNA has the nitrogenous base sequence at ATCTG, what ...

    Text Solution

    |

  10. Which one is the most abundant protein in the animal world?

    Text Solution

    |

  11. Even in absence of pollinating agents seed setting is assured in

    Text Solution

    |

  12. For transformation, micro -particles coated with DNA to be bombarded w...

    Text Solution

    |

  13. Which of the following statements is not true of two genes that show 5...

    Text Solution

    |

  14. Which of the following Bt crops is being grown in India by the farmers...

    Text Solution

    |

  15. The colonies of recombinant bacteria appear white in contrast to blue ...

    Text Solution

    |

  16. Kyoto Protocol was endorsed at

    Text Solution

    |

  17. If both parents are carriers for thalassemia , which is an autosomal r...

    Text Solution

    |

  18. Uridine,present only in RNA is a

    Text Solution

    |

  19. Satellite RNAs are present in some

    Text Solution

    |

  20. Which of the following has maximum genetic diversity in india ?

    Text Solution

    |