Question

Xylem and phloem are an example of…..?

Answer 1

Hint: Xylem is found in the outer wood of trees and transports water from the roots to the leaves. Phloem is found in tree bark and transports sugars (such as sucrose) and organic compounds from the leaves to the rest of the plant.

Complete answer:
The first fossils demonstrating the presence of vascular tissue date back to the Silurian period, approximately 430 million years ago. The most basic arrangement of conductive cells shows a xylem pattern in the centre surrounded by phloem. Plants' vascular system is made up of xylem and phloem tissues.

Complex permanent tissues can be described as collections of different types of cells that work together to perform a common function. Complex permanent tissues are also known as conducting vascular tissue because they are involved in the movement of various chemicals within the plant body.

Xylem is the tissue that supports the plant as well as stores and transports water and nutrients over long distances, including the transfer of water-soluble growth factors from the organs of synthesis to the target organs. The tissue is made up of vessel elements, conducting cells called tracheids, and supportive filler tissue known as parenchyma.

End-to-end connections of these cells form long tubes. At maturity, vessels and tracheids are extinct. Tracheids have tapered ends and thick secondary cell walls. The thick walls of the tracheids support the plant and allow it to grow to impressive heights. Tall plants have a selective advantage because they can reach unfiltered sunlight and disperse their spores or seeds further away, allowing them to spread their range.

Tall trees cast their shadow on shorter plants and limit competition for water and nutrients in the soil by growing higher than other plants. The tracheids do not have end openings like the vessels, but their ends do overlap with pairs of pits. Water can pass horizontally from cell to cell thanks to the pit pairs.

Translocation, or the transport of soluble organic substances such as sugar, is the responsibility of phloem tissue. The substances travel along sieve elements, but other types of cells, such as companion cells, parenchyma cells, and fibres, are also present. End walls, unlike vessel members in xylem, do not have large openings.

The end walls, on the other hand, are densely packed with small pores through which cytoplasm flows from cell to cell. Sieve plates are the name given to these porous connections. Despite the fact that their cytoplasm actively participates in food transport, sieve-tube members do not have nuclei when they reach maturity. Companion cells control the activity of the sieve tubes via plasmodesmata.

Xylem and phloem are examples of Complex tissue or Vascular tissues.

Note: Photosynthesis in leaves necessitates a large amount of water from the xylem and generates a large amount of sugar for the phloem. The xylem and phloem enter the leaves of a plant via the petiole, which is a short stalk that connects a leaf to a branch. Xylem and phloem run the length of stems in discrete threads known as 'vascular bundles.' The xylem and phloem are developed within the central section of a root known as a 'stele’.