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Hormones or plant growth regulators and ...

Hormones or plant growth regulators and other chemical stimuli are also transported though in very small amounts, sometimes in a strictly polarised or unidirectional manner.

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### Step-by-Step Solution: 1. **Understanding the Statement**: The statement discusses the transport of hormones or plant growth regulators and other chemical stimuli in plants. It claims that these substances are transported in very small amounts and can be transported in a strictly polarized or unidirectional manner. 2. **Defining Hormones**: Hormones in plants, known as phytohormones, are chemical substances that regulate various aspects of growth and development. They play crucial roles in processes such as cell division, elongation, and differentiation. 3. **Transport Mechanisms**: The transport of these hormones can occur through two main mechanisms: - **Passive Transport**: This process does not require energy and occurs along the concentration gradient (from high concentration to low concentration). - **Active Transport**: This process requires energy to move substances against the concentration gradient (from low concentration to high concentration). 4. **Unidirectional Transport**: The term "unidirectional" refers to the movement of substances in one direction. In the context of plant hormones, this means that once hormones are produced in one part of the plant, they move to another part without reversing direction. 5. **Examples of Unidirectional Transport**: - An example of unidirectional transport is the movement of water through the xylem, which transports water from the roots to the stem and leaves. This is a clear instance of unidirectional flow, as water typically moves upward and does not return to the roots. 6. **Conclusion**: Based on the definitions and examples provided, the statement can be evaluated. It accurately describes the transport of hormones and chemical stimuli in plants as occurring in very small amounts and in a strictly polarized or unidirectional manner. 7. **Final Answer**: The statement is **True**.
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How many of the following statements are not correct? [I] In a flowering plant the substances that would need to be transported are water, mineral nutrients, organic nutrients and plant growth regulators. [II] Over small distances, substances move by diffusion and by cytoplasmic streaming supplemented only by passive transport. [III] Organic and mineral nutrients undergo multidirectional transport through the xylem. [IV] From the storage organs, organic compounds are later re-exported. [V] Phytohormones and other chemical signals are transported to maintain and regulate the plant functions.

Both alkali metals and alkaline earth metals are s- block elements. They resemble each other in many respects but still there are certain dissimilarities in their properties due to different number of electrons in the valence shell, different atomic radii, ionisation enthalpy, electronegativity, etc. Like lithium, Be also differs from rest of the alkaline earth metals on account of its small atomic size and high electronetativity. Be^(2+) ion is very small and exerts a high polarising effect on any anion associated with it. The correct sequence of increasing covalent character is

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Both alkali metals and alkaline earth metals are s- block elements. They resemble each other in many respects but still there are certain dissimilarities in their properties due to different number of electrons in the valence shell, different atomic radii, ionisation enthalpy, electronegativity, etc. Like lithium, Be also differs from rest of the alkaline earth metals on account of its small atomic size and high electronetativity. Be^(2+) ion is very small and exerts a high polarising effect on any anion associated with it. The alkaline earth metal which does no directly combine with hydrogen is

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Read the following statements and find out the INCORRECT statement. a. Plant growth is unique because plants retain the capacity for unlimited growth throughout their life. b. Growth, at a cellular level , is principally a consequence of the increase in the amount of protoplasm. c. One single maize root apical meristem can give rise to more than 3,50,00 new cells per hour , whereas cells in watermelon may increase in size by up to 17, 500 times. d. Environmental signals such as light , temperature and gravity also affect certain phases or stages of growth. e. In geometric growth, following mitotic cell division , only one daughter cell continues to divide while the other differentiates adn matures.

Collision is a physical process in which two or more objects, either particle masses or rigid bodies, experience very high force of interaction for a very small duration. It is not essential for the objects to physically touch each other for collision to occur. Irrespective of the nature of interactive force and the nature of colliding bodies, Newton's second law holds good on the system. Hence, momentum of the system before and after the collision remains conserved if no appreciable external force acts on the system during collision. The amount of energy loss during collision, if at all, is indeed dependent on the nature of colliding objects. The energy loss is observed to be maximum when objects stick together after collision. The terminology is to define collision as 'elastic' if no energy loss takes place and to define collision as 'plastic' for maximum energy loss. The behaviour of system after collision depends on the position of colliding objects as well. A unidirectional motion of colliding objects before collision can turn into two dimensional after collision if the line joining the centre of mass of the two colliding objects is not parallel to the direction of velocity of each particle before collision. Such type of collision is referred to as oblique collision which may be either two or three dimensional. For which of the following collisions, the external force acting on the system during collision is not appreciable as mentioned in paragraph 1.

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Collision is a physical process in which two or more objects, either particle masses or rigid bodies, experience very high force of interaction for a very small duration. It is not essential for the objects to physically touch each other for collision to occur. Irrespective of the nature of interactive force and the nature of colliding bodies, Newton's second law holds good on the system. Hence, momentum of the system before and after the collision remains conserved if no appreciable external force acts on the system during collision. The amount of energy loss during collision, if at all, is indeed dependent on the nature of colliding objects. The energy loss is observed to be maximum when objects stick together after collision. The terminology is to define collision as 'elastic' if no energy loss takes place and to define collision as 'plastic' for maximum energy loss. The behaviour of system after collision depends on the position of colliding objects as well. A unidirectional motion of colliding objects before collision can turn into two dimensional after collision if the line joining the centre of mass of the two colliding objects is not parallel to the direction of velocity of each particle before collision. Such type of collision is referred to as oblique collision which may be either two or three dimensional. According to the definition of oblique collision in the paragraph, which of the following collisions cannot be oblique'?

ALLEN-TRANSPORT IN PLANTS-EXERCISE
  1. During early spring roots act as a (A) of food while buds of trees act...

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  2. The direction of movement in the phloem is (A) while in the xylem move...

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  3. Hormones or plant growth regulators and other chemical stimuli are als...

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  4. Compounds from storage organs are never re-exported

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  5. Diffusion is the only means of gaseous movement within plant body

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  6. Energy expenditure takes place in diffusion

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  7. The diffusion rate depends on the size of the substances

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  8. Diffusion is a slow process and is not dependent on a living system.

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  9. Facilitated diffusion and active transport both shows transport satura...

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  10. Like enzymes, carrier proteins are not very specific to respective tra...

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  11. Facilitated diffusion and active transport both are affected by inhibi...

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  12. Water is essential for all physiological activities of the plant and p...

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  13. The protoplasm of the cells is nothing but water in which different mo...

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  14. Terrestrial palnts take up huge amount of water but very less is evapo...

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  15. Most herbaceous plants have only about 10 to 15 percent of it's fresh ...

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  16. Water potential is denoted by the greek symbol Psi(Psi) and is express...

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  17. Contents of vacuole does not contribute to the solute potential of the...

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  18. Study the given figure carefully and select the true and false:- state...

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  19. Study the given figure carefully and select the true and false stateme...

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  20. Because of the rigidity of cell wall the cell does not rupture.

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