You are given a tissue with its potential for differentiation in an artificial culture. Which of the following pairs of hormones would you add to the medium to secure shoots as well as roots?
You are given a tissue with its potential for differentiation in an artificial culture. Which of the following pairs of hormones would you add to the medium to secure shoots as well as roots?
The correct option is A Auxin and cytokinin
The correct option is A.
Explanation of the correct option:
- Auxin and cytokinin are the two growth hormones that favour cell division and differentiation.
- Auxin promotes root development, cell division and differentiation of xylem.
- Cytokinins promote cytokinesis which means a division of cells and are generally secreted in the areas where rapid cell division occurs.
- The proportion of cytokinin to auxin is regulated in calculated proportion to induce differentiation in the callus.
- Lower levels of cytokinin and higher levels of auxin promote the formation of roots and higher levels of cytokinin and lower levels of auxin concentrations promote differentiation of shoot.
Explanation of the incorrect options:
Option B:
IAA is a type of auxin that promotes shoot development but gibberellin is a growth hormone that promotes the development of fruits, seeds, etc.
Option C:
Gibberellin and abscisic acid controls seed and bud dormancy and maintains the defence mechanism of the plant.
Option D:
Auxin promotes cell differentiation but abscisic acid prevents cell division and promotes senescence of certain organs in the plant body.
Final answer: If one is given tissue with its potential for differentiation in artificial culture, auxin and cytokinin are the hormones that one would add to the medium to secure shoots as well as roots.
Auxin and cytokinin
The correct option is A.
Explanation of the correct option:
- Auxin and cytokinin are the two growth hormones that favour cell division and differentiation.
- Auxin promotes root development, cell division and differentiation of xylem.
- Cytokinins promote cytokinesis which means a division of cells and are generally secreted in the areas where rapid cell division occurs.
- The proportion of cytokinin to auxin is regulated in calculated proportion to induce differentiation in the callus.
- Lower levels of cytokinin and higher levels of auxin promote the formation of roots and higher levels of cytokinin and lower levels of auxin concentrations promote differentiation of shoot.
Explanation of the incorrect options:
Option B:
IAA is a type of auxin that promotes shoot development but gibberellin is a growth hormone that promotes the development of fruits, seeds, etc.
Option C:
Gibberellin and abscisic acid controls seed and bud dormancy and maintains the defence mechanism of the plant.
Option D:
Auxin promotes cell differentiation but abscisic acid prevents cell division and promotes senescence of certain organs in the plant body.
Final answer: If one is given tissue with its potential for differentiation in artificial culture, auxin and cytokinin are the hormones that one would add to the medium to secure shoots as well as roots.
