Home
Class 12
BIOLOGY
While creation and presence of variation...

While creation and presence of variation is directionless, natural selection is directional as it is in the context of adaptation. Comment.

Text Solution

Verified by Experts

Creation and variation occur in a sexually reproducing population as a result of crossing over during meiosis and random fusion of gametes. It is however the organisms that are selected over a period of time which are determined by the environmental conditions. n other words, the environment provides the direction with respect to adaptations so that the organisms are more and more fit in terms of survival
Promotional Banner

Topper's Solved these Questions

  • GENETICS AND EVOLUTION

    TRUEMAN BIOLOGY|Exercise SECTION-C|45 Videos
  • GENETICS AND EVOLUTION

    TRUEMAN BIOLOGY|Exercise SECTION-D|25 Videos
  • GENETICS AND EVOLUTION

    TRUEMAN BIOLOGY|Exercise SECTION-D|25 Videos
  • Genetics

    TRUEMAN BIOLOGY|Exercise ASSERTION AND REASON|122 Videos
  • HUMAN HEALTH AND DISEASE

    TRUEMAN BIOLOGY|Exercise MULTIPLE CHOICE QUESTIONS|211 Videos

Similar Questions

Explore conceptually related problems

Explain the following two components of Darwin's theory of natural selection. Variations

Variation in gene frequencies within populations can occur by chance rather than by natural selection. This is referred to as

Select the correct statement(s). (i) Adaptative ability is inherited. (ii) Adaptative ability has a genetic basis (iii) Fitness is the end result of the ability to adapt and get selected by nature.

Fitness is the end result of the ability to adapt and get selected by Nature. Explain with suitable example.

Given : 1 = Natural selection , 2 = Variations and their inheritance , 3 = Survival of the fittest , 4 = struggle for existence According the Darwinism, which of the following represents the correct squence of events in the origin of new species ?

TRUEMAN BIOLOGY-GENETICS AND EVOLUTION -SECTION-B
  1. Name the accepted model of plasma membrane. Who proposed it?

    Text Solution

    |

  2. What are the functions of (i) methylated guanasine cap, (ii) poly-A"ta...

    Text Solution

    |

  3. Differentiate between Exons and Introns.

    Text Solution

    |

  4. Comment on the utility of variability in number of tandem repeats duri...

    Text Solution

    |

  5. Write the full of VNTR. How is VNTR different from 'Probe' ?

    Text Solution

    |

  6. A non-haemophilic couple was infomed by their doctor that there is pos...

    Text Solution

    |

  7. In a particular plant species majority of the plants bear purple flowe...

    Text Solution

    |

  8. A cross between a red flower bearing plant and a white flower bearing ...

    Text Solution

    |

  9. In a typical monohybrid cross the F(2)-population ratio is written as ...

    Text Solution

    |

  10. Work out a cross to find the genotype of a tall pea plant. Name the ty...

    Text Solution

    |

  11. (a) Write the specific features of the genetic code AUG (b) Explain...

    Text Solution

    |

  12. Arrange the following groups of plants in an ascending evolutionary s...

    Text Solution

    |

  13. While creation and presence of variation is directionless, natural sel...

    Text Solution

    |

  14. Define Genetic drift. Mention the types.

    Text Solution

    |

  15. Who proposed ''survival of the fittest'' theory?

    Text Solution

    |

  16. In which plant did Mendel perform his experiments? Why did he choose i...

    Text Solution

    |

  17. Define migration. Mention the types of migration in fishes.

    Text Solution

    |

  18. How do darwin' s finches illustrate adaptive radiation ?

    Text Solution

    |

  19. List the two main propositions of Oparin and Haldane.

    Text Solution

    |

  20. Write the Oparin and Haldane hypothesis about the origin of life on Ea...

    Text Solution

    |