Biology · Plant Growth and Development · NEET
No. Growth is only an irreversible increase in size, area, length, volume, or cell number. Development is much wider: it is the sum of growth AND differentiation, covering every change from seed germination all the way to senescence. So growth is just one part of development.
NCERT says: 'Development is a term that includes all changes that an organism goes through during its life cycle from germination of the seed to senescence.' Learn the two boundary words for NEET: germination (start) and senescence (end).
NCERT gives a diagrammatic sequence (Figure 13.8) for a single cell of a higher plant: the cell first undergoes growth by cell division and cell enlargement, then differentiation into a mature cell, and later it may undergo dedifferentiation and redifferentiation. This same sequence also applies to tissues and organs, not just single cells.
Because a plant does not just get bigger — its cells also change into specialised types (like xylem, phloem, epidermis). Getting bigger is growth; becoming specialised is differentiation. Adding both together over the full life cycle gives development. NCERT states 'development is considered as the sum of growth and differentiation.'
No. Development continues throughout the life cycle up to senescence. Because plant growth is indeterminate (open) and meristems keep working, plants keep forming new organs, so developmental changes keep happening even in a mature plant.
Development is controlled by intrinsic (internal) and extrinsic (external) factors. Intrinsic factors are intracellular genetic factors and intercellular chemicals such as plant growth regulators (PGRs). Extrinsic factors are the environment — light, temperature, water, oxygen, and nutrition.
Try the real previous-year questions from this chapter — each with the answer and a full solution.
Development is the sum total of all changes an organism goes through during its life cycle, from germination of the seed to senescence.
Development = Growth + Differentiation. This is a direct NCERT statement and a common one-mark question.
It starts at germination of the seed and ends at senescence (ageing/death). Remember 'seed to senescence.'
No. The sequence shown in Figure 13.8 is for a cell of a higher plant, but NCERT clearly says it is also applicable to tissues and organs.
Plasticity is the ability of plants to follow different developmental pathways in response to the environment or phase of life, e.g., heterophylly. It is covered in the next concept, plasticity-in-plants.
