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Stage/Process | Details |
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1. Development |
– Development is the sum of two processes: Growth and Differentiation. – Begins from the Zygote (fertilized egg). – Follows a precise and highly ordered succession of events. – Forms a complex body organization that produces roots, leaves, branches, flowers, fruits, and seeds. – Ends with death after maturation. |
2. Cell Division | – Initial stage of development where cell division occurs. |
3. Meristematic Cell | – Formation of meristematic cells which are undifferentiated cells capable of division. |
4. Plasmatic Growth | – Plasmatic growth begins, contributing to the overall increase in cell size. |
5. Expansion (Elongation) | – Cells undergo expansion, leading to elongation and the development of tissues. |
6. Differentiation | – Cells specialize into different types of tissues and organs, marking the transition to mature cells. |
7. Maturation | – Mature cells undergo further development, contributing to the overall complexity of the plant structure. |
8. Aging |
– As the plant matures, it begins to age. – Aging involves a sum total of changes in the entire plant or its organs. – Chemical and structural changes occur during aging. – Aging leads to senescence. |
9. Senescence |
– Senescence is the deteriorative process that naturally terminates the functional life of an organ, organism, or life unit. – It is a phase of the aging process. – Characterized by catabolic metabolic processes that become irreversible and ultimately lead to death. – Senescence occurs at multiple levels: – Whole Plant: E.g., Wheat dies after fruiting. – Organs: E.g., Leaf fall in coconut trees. – Cells or Organelles: Individual cells or their components may undergo senescence. |
10. Abscission |
– Abscission refers to the shedding of leaves, flowers, and fruits. – Distinct in deciduous plants (all leaves fall at once in autumn) versus evergreen plants (gradual leaf fall throughout the year). – In many herbaceous species, leaves may not be shed even when dead. – During abscission, there are changes in pigmentation due to the degradation of chlorophyll and the synthesis of anthocyanin pigments. |
11. Death |
– Final stage of development. – Results from senescence, where metabolic processes cease, leading to the termination of plant life. – Involves abscission (shedding of non-functional parts). |
12. Determinate Growth | – Growth that stops after reaching a certain size or maturity; e.g., leaves and flowers grow to a specific size and then cease. |
13. Indeterminate Growth | – Growth that continues throughout the plant’s life; e.g., roots and stems can keep growing as long as the plant is alive and resources are available. |
14. Open Growth | – Indicates the presence of both determinate and indeterminate growth within the plant; some parts (like leaves) have fixed growth while others (like roots) do not. |
15. Open Differentiation | – Suggests that the final form or function of plant cells is not predetermined, allowing cells to adapt and differentiate based on their environment. |