Every question from this NCERT chapter, with a detailed explanation.
Consider the following statements: 1. Differentiation involves structural changes in cell wall and protoplasm. 2. Tracheary elements retain protoplasm at maturity to aid transport. 3. Secondary walls in conducting elements are lignocellulosic and strong. Which of the statements given above are correct?
Assertion (A): Differentiation in plants is strictly limited to the embryonic stage of development. Reason (R): Cells derived from root apical and shoot-apical meristems mature to perform specific functions.
Match the plant growth regulator with its chemical nature: List I | List II A. Indole-3-acetic acid (IAA) | 1. Gaseous hormone B. Kinetin | 2. Carotenoid derivative C. Abscisic acid (ABA) | 3. Adenine derivative D. Ethylene | 4. Indole compound Select the correct answer using the code given below
The ‘bakanae’ disease in rice led to the discovery of which class of Plant Growth Regulators (PGRs)?
Skoog’s observations on tobacco callus proliferation led to the isolation of which cytokinesis-promoting substance?
Which set of factors is most critical and immediate for extension growth at the cellular level in plants?
Assertion (A): Cell enlargement in plants is mainly driven by turgor pressure. Reason (R): Water is essential for all physiological activities of the plant and plays a role in enzymatic reactions.
With reference to growth in living systems, consider the following statements: 1. Increase in size due to simple imbibition qualifies as growth. 2. Expansion of a leaf is a case of growth. 3. Growth is accompanied by metabolic processes. 4. Growth is reversible under natural conditions. Which of the statements given above are correct?
Consider the following statements about cellular growth examples: 1. A single maize apical meristem can produce more than 17,500 new cells per hour. 2. Watermelon cells may increase in size by upto 3,50,000 times. Which of the statements given above is/are correct?
In assessing organ growth, which pairing is most appropriate?
Three independently reported inhibitors - inhibitor-B, abscission II and dormin - were later shown to be the same compound, now known as:
A volatile substance released by ripened oranges that hastened the ripening of stored bananas was later identified as:
Which of the following is a natural auxin and which is synthetic, respectively?
Assertion (A): Decapitation of the shoot tip usually results in the growth of lateral buds. Reason (R): The apical bud produces cytokinins which inhibit the growth of lateral buds.
Which one of the following is an auxin-induced phenomenon?
The sharp increase in respiration rate during fruit ripening promoted by ethylene is termed as:
Primary growth in plants is mainly due to the activity of:
Which curve best represents the growth of a plant organ in natural conditions over time?
The state in which seeds fail to germinate due to lack of favourable conditions and resume upon return of such conditions is:
Plants exhibit indeterminate growth throughout their life primarily due to the presence of:
Growth in a pollen tube is best expressed in terms of:
The cell walls of meristematic cells are characteristically:
The total growth of an organism per unit time is referred to as:
During the differentiation of tracheary elements, the cells undergo the loss of:
Chemically, kinetin is a modified form of which nitrogenous base?
The application of which plant growth regulator is commonly used to induce parthenocarpy in tomatoes?
The phenomenon of 'bolting' (internode elongation just prior to flowering) in rosette plants is promoted by:
In plants, natural cytokinins are synthesised primarily in regions of rapid cell division, such as:
Spraying sugarcane crops with which hormone increases the length of the stem, thereby increasing the yield?