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Xylem and phloem Flashcards | StudBud

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Phloem vessels also contain parenchyma

How is lignin laid down in the walls of xylem?

Xylem and phloem

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Quiz designed for OCR A-level Biology students to test very basic knowledge on plant tissues xylem and phloem

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Questions 10

Answers

1
How is lignin laid down in the walls of xylem?
In patches
As large inflexible sheets
As rings or spirals
Only where adjoining cell walls occur
2
Phloem vessels also contain parenchyma
True
False
3
How are xylem and phloem arranged in the stem?
Vascular bundle in centre of stem with X-shaped xylem on inside
Vascular bundles around outside with xylem on outside and phloem on inside
Vascular bundles around outside with phloem on outside and xylem on inside
As central mid-rib providing support as well as transport
4
Why do plants need a transport system?
Leaves can't access water directly
low surface area : volume ratio
Roots can photosynthesise (no light)
All of the above
5
Phloem vessels need their companion cells to keep them alive
True
False
6
What are pits?
The large spaces between adjacent cells making up xylem vessels
The name for the perforations that are present in sieve plates
Areas of xylem lacking lignin, allowing water to move in and out
Tiny holes in the cell wall of plant cells allowing exchange of substances
7
Companion cells connect with their sieve tube element via plasmodesmata
True
False
8
Xylem vessels are dead
False
True
9
Sugars are moved in the phloem in the form of
glucose
sucrose
fructose
maltose
10
What is the reason vascular bundles are distributed around the edge of the stem?
To allow easy access to the water and sucrose it carries
To give structural support, eg when stem bends in the wind