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Biology

GCSE · Edexcel

QuestionsFlashcards

Photosynthesis
Plant Structure
Transport in Plants
Plant Hormones
- Plant Hormones & Growth
  7
- Using Plant Hormones Commercially
  7

Transport in Animals
- The Need for Transport
  7
- Factors Affecting the Rate of Diffusion
  7
Respiration
- Respiration
  6
- Practical: Investigating Respiration
  5
Gas Exchange
Circulatory System
- The Blood & Blood Vessels
  6
- The Circulatory System
  8

Xylem & Phloem Flashcards

All 7 cards in this deck

What does xylem transport, and in which direction?: Water and dissolved mineral ions, upwards from the roots to the stem and leaves only.
What does phloem transport, and in which direction?: Sucrose (dissolved sugars), both up and down the plant to where it is needed.
Which substance strengthens and waterproofs the walls of xylem vessels?: Lignin — it supports the plant and stops the hollow vessel collapsing.
True or false? Xylem is made of living cells.: False. Xylem is made of dead, lignified cells with no end walls, forming hollow tubes; phloem cells are living.
What are sieve plates in phloem?: Perforated end walls between phloem cells that let the sucrose solution flow from cell to cell.
What is the function of companion cells in phloem?: They contain many mitochondria and release energy to actively transport sucrose into the phloem.
True or false? Transport of sucrose in the phloem requires energy from the plant.: True. Phloem is made of living cells, which use energy to move sucrose around the plant.