A key to learning and studying Biology is practice and thorough reading of the theories included in the subject. Completing practice problems, memorising diagrams, working mind maps, etc. should be a core feature of a student’s daily study routine. Testing your understanding and knowledge of Biology by reviewing and working the practice problems, helps to know the areas your have mastered and those which you lack.
Questions given at the end of each chapter of NCERT book play very crucial role for practicing different concepts and assessing your learning. These questions are also important from examination’s point of view as most of the questions in exams are designed in the similar manner as given in the NCERT books.
In this article, you will get the NCERT Solutions for CBSE class 11 Biology chapter 15 - Plant Growth and Development. All the questions have been solved in the most appropriate and simple way so as to help students access the right study material for the exam preparation.
Some of the questions and their solutions from NCERT Solutions for Class 11: Plant Growth and Development, are as follows:
Q. Why is not any one parameter good enough to demonstrate growth throughout the life of a flowering plant?
Ans. In plants, different parts grow in different ways, so measurement of growth should be done in different ways in them. Moreover, growth at a cellular level is principally a consequence of increase in the amount of protoplasm whose measurement involves many parameters such as the weight of the fresh tissue sample, the weight of the dry tissue sample, values of length, area, volume, and cell number measured during the growth period. Hence, measuring the growth of plants using only one parameter does not provide enough information and is therefore insufficient for demonstrating growth.
Q. Why is Abscisic acid also known as stress hormone?
Ans. Abscisic acid induces various responses in plants against stress conditions and increases the tolerance of plants to various kinds of stresses. Therefotre, it is also known as a stress hormone. Various adverse conditions like drought, water logging, etc., stimulate the production of this hormone. For example: Abscisic acid stimulates the closure of stomata and thus helps in reducing water loss due to transpiration.
Q. ‘Both growth and differentiation in higher plants are open’. Comment.
Ans. Growth in case of higher plants is unique as they retain the capacity for unlimited growth throughout their life. This is because the meristems located at certain areas in the plant body are having cells which have the capacity to continuously divide and produce new cells. Hence, the growth in higher plants is of open type. Moreover, some of the cells arising from meristems, always undergo differentiation after some rounds of cell division. Hence, the differentiation in plants is also open.
CBSE Class 11 Biology Syllabus 2018 - 2019
Q. ‘Both a short day plant and a long day plant can flower simultaneously in a given place’. Explain.
Ans. Flowering in some plants depends on a combination of light and dark exposures and the relative duration of light and dark periods. A short day plant requires a longer dark period, while a long day plant requires a longer light period. So, both a short day plant and a long day plant can flower simultaneously in a given place, provided they have been given an adequate photoperiod.
Q. Would a defoliated plant respond to photoperiodic cycle? Why?
Ans. A defoliated plant will not respond to the photoperiodic cycle at all. Because leaves of a plant have the hormone florigen that makes them capable of responding to light and dark stimuli for the induction of flowering.
Get the complete the NCERT solutions for Class 11: Plant Growth and Development, from the following link:
Students may download the NCERT solutions for Class 11 Biology chapter- Plant Growth and Development, in the form of PDF.
Class 11 Biology NCERT Chapter: Plant Growth and Development
NCERT books are considered best source for clearing all the concepts and strengthen the fundamentals of a subject. With clear concepts and theories in mind, student will be able to break any problem and come up with right answers. Here we are providing the NCERT chapter for Class 11 Plant Growth and Development. Taking a thorough reading of the theories given in this chapter will help you solve different questions appropriately.
Main topics discussed in Class 11 Biology chapter: Plant Growth and Development are:
- Growth
Indeterminate
Measurable
- Phases of growth
- Growth rates
- Conditions for growth
- Differentiation, dedifferentiation and redifferentiation
- Development
- Plant growth regulators
Characteristics
Discovery of plant growth regulators
- Physiological effects of plant growth regulators
- Photoperiodism
- Vernalisation.
Find below the link to download the complete Chapter: