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

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

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

    TRUEMEN BIOLOGY ENGLISH|Exercise SECTION-D|25 Videos
  • Genetics

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

    TRUEMEN BIOLOGY ENGLISH|Exercise MULTIPLE CHOICE QUESTIONS|209 Videos

Similar Questions

Explore conceptually related problems

Natural selection leads to the directional change when

Differentiate between Directional natural selection and Disruptive natural selection.

Select the incorrect statement. ( i ) The essence of the Darwinian theory of evolution is natural selection (ii) Evolution is a directed process in the sense of determinism (III) The geological history of the earth is not related to the biological history of the earth (IV ) During evolution ,the rate of appearance of new forms is linked to the life cycle

According to Darwin, organic evolution proceeds in which of the following orders? (a) Overproduction, variations, constancy of population size , natural selection (b) variations, constancy of population size , Overproduction, natural selection (c) Overproduction, constancy of population size ,variations, natural selection (d) variations, natural selection ,Overproduction, constancy of population size

Pure lines and clones do not exhibit genetic variations for natural selection. Why?

Write in what context did Darwin use the terms ' fitness', survival and selection while elaborating on the mechanism of evolution.

Natural selection can lead to stabilisation, directional change or disruption. True/False

Read the following statements carefully. A. Studies suggest that first organisms that invaded land were plants. br B. Saltations are large mutations and directionless while Darwinian variations are small and directional. br C. Sauropsids were common ancestors of therapsids and thecodonts. br D. Homo habilis was the first hominid with brain capacity ranging between 650-800 cc. Choose the correct option w.r.t. True (T) and False (F) statements

The refractive index of a solid is observed to have the same value along all direction. Comment on the nature of this solid. Would it show cleavage property?

The refractive index of a solid is observed to have the same value along all direction. Comment on the nature of this solid. Would it show cleavage property?

TRUEMEN BIOLOGY ENGLISH-GENETICS AND EVOLUTION -SECTION-B
  1. What background information did Watson and Crick have made available f...

    Text Solution

    |

  2. What are the functions of (i) methylated guanine cap? (ii) poly...

    Text Solution

    |

  3. Do you think that the alternate splicing of exons may enable a structu...

    Text Solution

    |

  4. Comment on the utility of variability in number of tansem 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. Gene flow occurs through generations. Gene flow can occur across langu...

    Text Solution

    |

  15. When we say ' survival of the fittest ' , does it mean that (a) tho...

    Text Solution

    |

  16. Enumerate three most characteristic criteria for designating a Mendeli...

    Text Solution

    |

  17. Migration may enhance or blurr the effects of selection' comment.

    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

    |