Flashcards
Xylem and Phloem
Flashcards do conjunto (9)
- 1What is the role of xylem tissue?Xylem tissue transports water and minerals in solution
- 2What is the role of phloem tissue?Phloem tissue transports sugars both up and down the plant
- 3Describe the distribution of xylem and phloem tissue in the roots, stem and leaf
- 4Describe the structure of xylem vesselsLong, tube-like structures formed from vessel elements joined end-to-end
An uninterrupted tube
Cells are dead so they contain no cytoplasm
Cell walls are thickened with lignin (helps to support walls and prevents collapsing inwards)
Water and mineral ions move in and out through small pits - 5The cell walls of xylem vessels are thickened with lignin. Why?Lignin helps to support the walls and prevents the cell from collapsing inwards
- 6TRUE OR FALSE: The amount of lignin in xylem vessels increases as the cell gets olderTRUE
- 7Describe the structure of phloem vesselsTissue contains phloem fibres, parenchyma, sieve tube elements and companion cells
Sieve tube elements are joined end-to-end
Companion cells have no nucleus - 8What are the properties of sieve tube elements?No nucleus
Very thin layer of cytoplasm
Few organelles
Connected through holes in the sieve plates - 9What is the role of companion cells?Companion cells carry out the living functions for both themselves and their sieve cells.
E.g. they provide energy for active transport of solutes
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- O usuário eliminou as informações de disciplina FlashCards sobre Xylem and Phloem, criado por Usuário eliminado em 05-03-2018.
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- Usuário eliminado · mar 2018
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- 5 mar 2018
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- Criado por Yinka F · 2 fev 2018
- Copiado por Yinka F · 5 mar 2018
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