Home
Class 12
BIOLOGY
[A]: Light is very important external fa...

[A]: Light is very important external factor of transpiration.
[R]: Light induces stomata! opening and darkness stomata! closure. Thus the rate of transpiration increases in light and de- creases in dark.

A

1)If both A and R are true and R is the correct explanation of A

B

2)If both A and R are true but R is not the correct explanation of A

C

3)If A is true and R is false

D

4)If both A and R are false

Text Solution

Verified by Experts

The correct Answer is:
A
Promotional Banner

Topper's Solved these Questions

  • Plant Morphology & Reproduction

    TRUEMAN BIOLOGY|Exercise ASSERTION AND REASON|62 Videos

  • PRINCIPLES OF INHERITANCE AND VARIATIONS

    TRUEMAN BIOLOGY|Exercise MCQs|343 Videos

Similar Questions

Explore conceptually related problems

Potometer is used to measure: 1.Light intensity 2.Growth rate 3.Photosynthetic rate 4.Transpiration rate.

Which of the following factors is most important in regulation of transpiration? (a) Relative humidity (b) Temperature (c) Light (d) Wind

Einstein established the idea of photons on the basis of Planck's quantum theory. According to his idea, the light of frequency f or wavelength lamda is infact a stream of photons. The rest mass of each photon is zero and velocity is equal to the velocity of light (c) = 3 xx 10^(8) m.s^(-1) . Energy, E = hf, where h = Planck's constant = 6.625 xx 10^(-34)J.s . Each photon has a momentum p = (hf)/(c) , although its rest mass is zero. The number of photons increase when the intensity of incident light increases and vice-versa. On the other hand, according to de Broglie any stream of moving particles may be represented by progressive waves. The wavelength of the wave (de Broglie wavelength) is lamda = (h)/(p) , where p is the momentum of the particle. When a particle having charge e is accelerated with a potential difference of V, the kinetic energy gained by the particle is K= eV. Thus as the applied potential difference is increased, the kinetic energy of the particle and hence the momentum increase resulting in a decrease in the de Broglie wavelength. Given, charge of electron, e = 1.6 xx 10^(-19)C and mass = 9.1 xx 10^(-31) kg . The number of photons emitted per second by a source of light of power 30 W is 10^(20) , the momentum of each photon (in kg.m.s^(-1) )

Einstein established the idea of photons on the basis of Planck's quantum theory. According to his idea, the light of frequency f or wavelength lamda is infact a stream of photons. The rest mass of each photon is zero and velocity is equal to the velocity of light (c) = 3 xx 10^(8) m.s^(-1) . Energy, E = hf, where h = Planck's constant = 6.625 xx 10^(-34)J.s . Each photon has a momentum p = (hf)/(c) , although its rest mass is zero. The number of photons increase when the intensity of incident light increases and vice-versa. On the other hand, according to de Broglie any stream of moving particles may be represented by progressive waves. The wavelength of the wave (de Broglie wavelength) is lamda = (h)/(p) , where p is the momentum of the particle. When a particle having charge e is accelerated with a potential difference of V, the kinetic energy gained by the particle is K= eV. Thus as the applied potential difference is increased, the kinetic energy of the particle and hence the momentum increase resulting in a decrease in the de Broglie wavelength. Given, charge of electron, e = 1.6 xx 10^(-19)C and mass = 9.1 xx 10^(-31) kg . Two stationary electrons are accelerated with potential difference V_(1) and V_(2) respectively such that V_(1) : V_(2) = n . The ratio of their de Broglie wavelength

[A]: Photosynthesis is an oxidation reduction process. [R]: Light reaction involves oxidation of water & dark reaction involves reduction of CO_2

Einstein established the idea of photons on the basis of Planck's quantum theory. According to his idea, the light of frequency f or wavelength lamda is infact a stream of photons. The rest mass of each photon is zero and velocity is equal to the velocity of light (c) = 3 xx 10^(8) m.s^(-1) . Energy, E = hf, where h = Planck's constant = 6.625 xx 10^(-34)J.s . Each photon has a momentum p = (hf)/(c) , although its rest mass is zero. The number of photons increase when the intensity of incident light increases and vice-versa. On the other hand, according to de Broglie any stream of moving particles may be represented by progressive waves. The wavelength of the wave (de Broglie wavelength) is lamda = (h)/(p) , where p is the momentum of the particle. When a particle having charge e is accelerated with a potential difference of V, the kinetic energy gained by the particle is K= eV. Thus as the applied potential difference is increased, the kinetic energy of the particle and hence the momentum increase resulting in a decrease in the de Broglie wavelength. Given, charge of electron, e = 1.6 xx 10^(-19)C and mass = 9.1 xx 10^(-31) kg . The number of photons emitted per second from a light source of power 40 W and wavelength 5893 Å

Human skin colour is polygenic trait with each dominant determing a part of melanin deposition while the recessive are coding for no melanin. If a very dark skinned person marries a very light skinned women, the chances of a very dark skinned offspring are

[A]: Xanthium will not flower if the long dark period is interrupted by a single brief flash of light. [R]: Xanthium is a long day plant where continuous long light period as essential for flowering.

[A]: The rate of photosynthesis is determined in terms of the rate of production either per unit mass of green tissue or per unit weight of total chlorophyll. [R]: Amount of light, CO_2 supply and temperature are important internal factors 'that directly affect the photosynthesis.

TRUEMAN BIOLOGY-Plant Physiology -ASSERTION AND REASON
  1. [A]: Hill and Bendall proposed Z-scheme and suggested that photosystem...

    Text Solution

    |

  2. [A]: Rhizobial aggregates have been observed at distinct sites on curl...

    Text Solution

    |

  3. [A]: Light is very important external factor of transpiration. [R]:...

    Text Solution

    |

  4. [A]: Wax, resin and suberin coating on the surface of plant parts redu...

    Text Solution

    |

  5. [A]: Gibberellic acid when added to isolated aleurone layer, induces a...

    Text Solution

    |

  6. Assertion : Auxillary buds, in actively growing herbaceous plants, gen...

    Text Solution

    |

  7. Assertion : If you burn a plant , its nitrogen component is given of...

    Text Solution

    |

  8. [A]: Amino acids are converted into ammonia by a group bacteria called...

    Text Solution

    |

  9. [A]: Due to excessive use of fertilizers, the available water to the p...

    Text Solution

    |

  10. [A]: Vernalization is also called as yarovization. [R]: In short day...

    Text Solution

    |

  11. [A]: Fundamental factor in the vernalization is low temperature. [R...

    Text Solution

    |

  12. [Aj: ABA plays an important role in plants during water stress and dro...

    Text Solution

    |

  13. (A]: Cytokinins help in retention of cholorophyll and delayed senescen...

    Text Solution

    |

  14. [A]: The germination of lettuce seeds is stimulated by red light and i...

    Text Solution

    |

  15. [A]: The far-red form of the phytochromes ab- sorb light at 740 nm. ...

    Text Solution

    |

  16. [A]: Elongation and division of cells are pro- moted by gibberellins. ...

    Text Solution

    |

  17. [A]: Senescence effect can be reversed by cytokinin. [R]: The loss ...

    Text Solution

    |

  18. [A]: Wilting occurs due to loss in turgidity. [R]: Turgor pressure c...

    Text Solution

    |

  19. [A]: Plasmolysis is seen by both living and dead cells. [R]: Both ty...

    Text Solution

    |

  20. [A]: The water is absorbed by the root and moves into the stem. [R]...

    Text Solution

    |