Growth and Development in Plants MCQs for NEET — Botany Questions with Answers

The NCERT text explains: 'This ability of the plants is due to the presence of meristems at certain locations in their body. The cells of such meristems have the capacity to divide and self-perpetuate. The product, however, soon loses the capacity to divide and such cells make up the plant body. This form of growth wherein new cells are always being added to the plant body by the activity of the meristem is called the open form of growth.' (Chapter: PLANT_GROWTH_AND_DEVELOPMENT, Section 13.1.1).

Relative growth rate is calculated per unit initial parameter. If both leaves increase by the same absolute amount (5 cm²), the leaf with a smaller initial area will have a higher relative growth rate (percentage increase) compared to a larger leaf. For example, if Leaf A is 10 cm² and grows to 15 cm², its relative growth is 50%. If Leaf B is 100 cm² and grows to 105 cm², its relative growth is 5%. (Chapter: PLANT_GROWTH_AND_DEVELOPMENT, Section 13.1.4 and Figure 13.7).

As per NCERT, 'The constantly dividing cells, both at the root apex and the shoot apex, represent the meristematic phase of growth. The cells in this region are rich in protoplasm, possess large conspicuous nuclei. Their cell walls are primary in nature, thin and cellulosic with abundant plasmodesmatal connections.'

NCERT states, 'The cells proximal (just next, away from the tip) to the meristematic zone represent the phase of elongation. Increased vacuolation, cell enlargement and new cell wall deposition are the characteristics of the cells in this phase.'

NCERT mentions, 'Growth, at a cellular level, is principally a consequence of increase in the amount of protoplasm.'

The NCERT text states, 'Growth is, therefore, measured by a variety of parameters some of which are: increase in fresh weight, dry weight, length, area, volume and cell number.'

NCERT provides these examples: 'In the former, growth is expressed as increase in cell number; the latter expresses growth as increase in size of the cell.' This indicates that growth encompasses both aspects.

As stated in the NCERT text, 'On plotting the length of the organ against time, a linear curve is obtained' for arithmetic growth.

The NCERT explicitly states: '$e$ = base of natural logarithms' in the exponential growth equation.

The text lists water, oxygen, and nutrients as 'very essential elements for growth.' While gravity affects certain phases/stages of growth, it is described as an 'environmental signal' rather than a 'necessary condition' in the same primary sense as water, oxygen, and nutrients for growth processes like cell enlargement and metabolic energy.