Mature sieve tubes are specialized structures found in the phloem of plants. They are responsible for transporting organic materials such as sugars, amino acids, and hormones throughout the plant body. Mature sieve tubes are different from vessels, which are another type of structure found in the plant body that helps in water transport.

Difference between Mature sieve tube and vessels:

Absence of Lignified Wall:
The major difference between mature sieve tubes and vessels is that sieve tubes lack a lignified wall, while vessels have a lignified wall. The absence of a lignified wall makes the sieve tube more flexible and able to withstand the pressure of the moving fluids.

Functional Nuclei:
Additionally, mature sieve tubes lack functional nuclei, while vessels have dead cells. This means that the sieve tube is unable to repair itself or respond to changing conditions. Vessel cells, on the other hand, are able to respond to changes in the environment and can actively transport water and minerals.

Cytoplasm:
Mature sieve tubes have a small amount of cytoplasm, while vessels have no cytoplasm. This means that sieve tubes are able to actively transport organic materials, while vessels are only able to transport water and minerals.

Conclusion:
In conclusion, mature sieve tubes are an important part of the phloem in plants, responsible for transporting organic materials throughout the plant body. They differ from vessels in several ways, including the absence of a lignified wall, functional nuclei, and the presence of cytoplasm.