Home
Class 12
BIOLOGY
Assertion The quiescentcentre actsas a r...

Assertion The quiescentcentre actsas a reservoir of relatively resistant cells, which constitute a permanent source of active initials.
Reason The cells of the inactive region of quiescent centre become active,when the previous active initials get damaged.

A

Both A and R are true and R is the correct explanation of A

B

Both A and R are true, but R is not the correct explanation of A

C

A is true, but R is false

D

A and R are false

Text Solution

Verified by Experts

The correct Answer is:
A
Ouieacent centre is found in the centre of the root apex. Cell divisions are very few in the quiescent centre. It may function as reserve meristem.
Promotional Banner

Topper's Solved these Questions

  • SOLVED PAPERS 2018

    ARIHANT NEET|Exercise Solved Paper 2018 (JIPMER)|41 Videos

  • SOLVED PAPERS 2018

    ARIHANT NEET|Exercise Solved Paper 2018 (JIPMER)|41 Videos

  • SOLVED PAPERS 2017

    ARIHANT NEET|Exercise Solved Paper 2017 (JIPMER)|35 Videos

  • STRUCTURAL ORGANISATION IN SOME ANIMALS

    ARIHANT NEET|Exercise CHAPTER EXERCISES (C) MEDICAL ENTRANCES GALLERY (COLLECTION OF QUESTIONS ASKED IN NEET & VARIOUS ENTRANCE EXAMS )|48 Videos

Similar Questions

Explore conceptually related problems

Assertion : Quiescent centre is found in the centre of the root apex. Reason : It consists of actively dividing cells .

Assertion Permanent tissue is composed of mature cells. Reason Meristematic tissue is a group of actively dividing cells.

Assertion : Permanent tissue is composed of mature cells. Reason : Meristematic tissue is a group of actively dividing cells.

The active molecule that helps to initiate inflammatory response when mast cell degranulate is:

Read the following text and answer the following questions on the basis of the same: Ozone layer depletion: We are all exposed to UV radiation from the sun. The sun is by far the strongest source of ultraviolet radiation. UV radiation spectrum is divided into three regions called UVA, UVB and UVC. As sunlight passes through the atmosphere, all UVC and most UVB is absorbed by ozone, water vapour, oxygen and carbon dioxide. UVA is not filtered as significantly by the atmosphere. The three types of UV radiation are classified according to their wavelength. They differ in their biological activity and the extent to which they can penetrate the skin. The shorter the wavelength, the more harmful the UV radiation The UV region covers the wavelength range 100-400 nm and is divided into three bands: • UVA (315-400 nm) • UVB (280-315 nm) • UVC (100-280 nm). Short-wavelength UVC is the most damaging type of UV radiation. However, it is completely filtered by the atmosphere and does not reach the earth's surface UV level reaching the earth changes with latitude and altitude. UV levels are higher closer to the equator. Closer to the equator the sun's rays have a shorter distance to travel through the atmosphere and therefore harmful UV radiation absorption is less. With increasing altitude less atmosphere is available to absorb UV radiation. With every 1000 m in altitude, UV levels increase by approximately 10%. Ozone is a particularly effective absorber of UV radiation. As the ozone layer gets thinner, the protective filter activity is progressively reduced. Consequently, the people and the environment are exposed to higher levels of UV radiation, especially UVB. Ozone depletion is caused by human-made chemicals released into the atmosphere. Which UV band is not absorbed by the atmosphere?

Read the following text and answer the following questions on the basis of the same: Ozone layer depletion: We are all exposed to UV radiation from the sun. The sun is by far the strongest source of ultraviolet radiation. UV radiation spectrum is divided into three regions called UVA, UVB and UVC. As sunlight passes through the atmosphere, all UVC and most UVB is absorbed by ozone, water vapour, oxygen and carbon dioxide. UVA is not filtered as significantly by the atmosphere. The three types of UV radiation are classified according to their wavelength. They differ in their biological activity and the extent to which they can penetrate the skin. The shorter the wavelength, the more harmful the UV radiation The UV region covers the wavelength range 100-400 nm and is divided into three bands: • UVA (315-400 nm) • UVB (280-315 nm) • UVC (100-280 nm). Short-wavelength UVC is the most damaging type of UV radiation. However, it is completely filtered by the atmosphere and does not reach the earth's surface UV level reaching the earth changes with latitude and altitude. UV levels are higher closer to the equator. Closer to the equator the sun's rays have a shorter distance to travel through the atmosphere and therefore harmful UV radiation absorption is less. With increasing altitude less atmosphere is available to absorb UV radiation. With every 1000 m in altitude, UV levels increase by approximately 10%. Ozone is a particularly effective absorber of UV radiation. As the ozone layer gets thinner, the protective filter activity is progressively reduced. Consequently, the people and the environment are exposed to higher levels of UV radiation, especially UVB. Ozone depletion is caused by human-made chemicals released into the atmosphere. UV level is

Read the following text and answer the following questions on the basis of the same: Ozone layer depletion: We are all exposed to UV radiation from the sun. The sun is by far the strongest source of ultraviolet radiation. UV radiation spectrum is divided into three regions called UVA, UVB and UVC. As sunlight passes through the atmosphere, all UVC and most UVB is absorbed by ozone, water vapour, oxygen and carbon dioxide. UVA is not filtered as significantly by the atmosphere. The three types of UV radiation are classified according to their wavelength. They differ in their biological activity and the extent to which they can penetrate the skin. The shorter the wavelength, the more harmful the UV radiation The UV region covers the wavelength range 100-400 nm and is divided into three bands: • UVA (315-400 nm) • UVB (280-315 nm) • UVC (100-280 nm). Short-wavelength UVC is the most damaging type of UV radiation. However, it is completely filtered by the atmosphere and does not reach the earth's surface UV level reaching the earth changes with latitude and altitude. UV levels are higher closer to the equator. Closer to the equator the sun's rays have a shorter distance to travel through the atmosphere and therefore harmful UV radiation absorption is less. With increasing altitude less atmosphere is available to absorb UV radiation. With every 1000 m in altitude, UV levels increase by approximately 10%. Ozone is a particularly effective absorber of UV radiation. As the ozone layer gets thinner, the protective filter activity is progressively reduced. Consequently, the people and the environment are exposed to higher levels of UV radiation, especially UVB. Ozone depletion is caused by human-made chemicals released into the atmosphere. How many bands are there in UV radiation spectrum?

Read the following text and answer the following questions on the basis of the same: Ozone layer depletion: We are all exposed to UV radiation from the sun. The sun is by far the strongest source of ultraviolet radiation. UV radiation spectrum is divided into three regions called UVA, UVB and UVC. As sunlight passes through the atmosphere, all UVC and most UVB is absorbed by ozone, water vapour, oxygen and carbon dioxide. UVA is not filtered as significantly by the atmosphere. The three types of UV radiation are classified according to their wavelength. They differ in their biological activity and the extent to which they can penetrate the skin. The shorter the wavelength, the more harmful the UV radiation The UV region covers the wavelength range 100-400 nm and is divided into three bands: • UVA (315-400 nm) • UVB (280-315 nm) • UVC (100-280 nm). Short-wavelength UVC is the most damaging type of UV radiation. However, it is completely filtered by the atmosphere and does not reach the earth's surface UV level reaching the earth changes with latitude and altitude. UV levels are higher closer to the equator. Closer to the equator the sun's rays have a shorter distance to travel through the atmosphere and therefore harmful UV radiation absorption is less. With increasing altitude less atmosphere is available to absorb UV radiation. With every 1000 m in altitude, UV levels increase by approximately 10%. Ozone is a particularly effective absorber of UV radiation. As the ozone layer gets thinner, the protective filter activity is progressively reduced. Consequently, the people and the environment are exposed to higher levels of UV radiation, especially UVB. Ozone depletion is caused by human-made chemicals released into the atmosphere. Most harmful UV radiation band is

ARIHANT NEET-SOLVED PAPERS 2018-Solved Paper 2018 (AIIMS)
  1. Which of the following plants are used to treat bone fractures?

    Text Solution

    |

  2. C(4) pathway is advantageous over C(3) pathway in plants as it

    Text Solution

    |

  3. Which one of the following categories of organisms do not evolve oxyge...

    Text Solution

    |

  4. Which of the following biomolecules is common to respiration-mediated ...

    Text Solution

    |

  5. Arrange in correct order according to the given figures.

    Text Solution

    |

  6. Match the following columns

    Text Solution

    |

  7. Match the organisms given in Column I to their functions given in Colu...

    Text Solution

    |

  8. Assertion : Nitogen - fixing bacteria in legume root nodules survive i...

    Text Solution

    |

  9. Assertion: Cytochrome oxidase enzyme contian copper. Cyanide combine...

    Text Solution

    |

  10. Assertion Meiotic division occurs in reproductive cells. Reason Syna...

    Text Solution

    |

  11. Assertion The quiescentcentre actsas a reservoir of relatively resista...

    Text Solution

    |

  12. Assertion Two turns of Krebs cycle occur per glucose molecule used. ...

    Text Solution

    |

  13. Assertion: Pork should be properly cooked to avoid Taenia infection. ...

    Text Solution

    |

  14. Assertion: Magnesium is important in photosynthesis and carbohydrate m...

    Text Solution

    |

  15. Assertion The collenchyma is a thick-walled living tissue. Reason T...

    Text Solution

    |

  16. Assertion In mitosis, two identical cells are produced from a single c...

    Text Solution

    |

  17. Assertion Non-cyclic photophosphorylation occurs in the stroma of chlo...

    Text Solution

    |

  18. Assertion Taenia solium and Dugesia belong to Platyhelminthes. Reaso...

    Text Solution

    |

  19. Assertion: Photomodulation of flowering is phytochrome-regulated proc...

    Text Solution

    |

  20. Assertion Caryopsis fruits differ from typical achenes with respect to...

    Text Solution

    |