Movement of substances in xylem is unidirectional. Explain.

Flow of energy through various trophic levels in an ecosystem is unidirectional and non-cyclic . Explain

The translocation in phloem is unidirectional whereas in the xylem it is bidirectional.

Energy flow in an ecosystem is unidirectional. Comment.

Name the dead cells in xylem.

The blue colour of crystals of a substance changed on heating in a closed test tube but the colour was regained after some time on cooling. Name the substance and write its chemical formula. Explain the phenomenon involved.

What is xylem?

Write function of xylem.