Question

Senescence as an active developmental cellular process in the growth and functioning of a flowering plant, is indicated in

• A. annual plants
• B. floral parts
• C. vessels and tracheid differentiation
• D. leaf abscission.

Answer 1

The Correct Option is C

The question asks about the indication of senescence, an active developmental cellular process, in a flowering plant. Among the given options, we need to determine where senescence is prominently indicated.

Senescence in plants is a programmed process associated with the aging and eventual death of plant tissues, organs, and cells. This helps in recycling nutrients and maintaining overall plant health.

1. Annual plants: Senescence occurs here as the entire plant dies at the end of the lifecycle, but this is a more generalized form of senescence and not a specific cellular process.
2. Floral parts: While floral parts undergo senescence after pollination to facilitate fruit development, it doesn't distinctively describe a cellular process like cell differentiation.
3. Vessels and tracheid differentiation: This option correctly highlights senescence. In vascular plants, during the differentiation of xylem vessels and tracheids, senescence plays a critical role as programmed cell death. This process involves the death of cell contents, leaving behind empty cells for efficient water and nutrient conduction.
4. Leaf abscission: Leaf abscission is influenced by hormonal changes and involves senescence, but the differentiation of vessels and tracheids explicitly represents cellular process-related senescence.

Therefore, the correct answer is vessels and tracheid differentiation. This is because during their development, programmed cell death occurs leading to mature xylem that facilitates efficient transport within the plant.