To address the problem, it is necessary to understand the mechanisms of water movement within plants and identify the plant structures responsible for this process.
Plants possess various tissues, each with distinct functions. Among these, xylem and phloem are crucial components of the plant's vascular system, acting as its internal transport network.
- Xylem comprises specialized, elongated hollow tubes.
- Its primary function is to convey water and dissolved minerals, absorbed by the roots, upwards through the stem to the leaves.
- Water ascent is facilitated by phenomena such as capillary action, root pressure, and transpiration pull.
- Mature xylem cells are non-living, forming empty conduits that function as efficient channels for water transport.
- Phloem is another vascular tissue responsible for transporting nutrients, specifically sugars produced by the leaves via photosynthesis.
- It facilitates the movement of these sugars from the leaves (source) to other plant parts where they are utilized or stored (sink).
- In contrast to xylem, phloem cells are living and actively participate in distributing nutrients throughout the plant.
- The epidermis serves as the plant's outer protective layer and is not involved in water transport.
- Stomata are small pores, predominantly located on the leaf undersides, that regulate gas exchange (oxygen, carbon dioxide) and the release of water vapor. They do not, however, transport water internally.
Given that the inquiry concerns the internal transport of water in plants, the identified responsible tissue is the xylem, which is accountable for transporting water and minerals from the roots to all plant extremities.
The tissue responsible for water transport in plants is Xylem.
Growth curve ‘B’ shows a different pattern from that of growth curve ‘A’. Justify giving one reason.