3.3.1 The Need for Transport Systems in Plants Flashcards
Why do plants need a transport system?
All living organisms have the need to exchange substances with their surrounding environment
Plants need to take carbon dioxide and nutrients in
Waste products generated need to be released
What does every cell in a plant require?
Every cell in a plant requires water, glucose and mineral ions
How does every cell in a plant obtain water, glucose and mineral ions?
The roots of a plant take in water and mineral ions while the leaves produce glucose by photosynthesis
These molecules need to be transported to the other parts of the plant
Glucose is transported as sucrose in plants
What are the adaptations of plants to increase SA:Vol?
There are several adaptations present in plants that help to increase their SA: V ratio
Plants have a branching body shape
Leaves are flat and thin
Roots have root hairs
Why do plants have a lower demand for oxygen in aerobic respiration?
Plant cells and tissues have a much lower metabolic rate than animal cells
Therefore their demand for oxygen for aerobic respiration is reduced
What is a mass transport system in plants?
Plants have evolved specialised mass flow transport systems that enable the efficient transport of nutrients and waste
Mass flow is the bulk movement of materials. It is directed movement so involves some source of force
What are the two separate mass transport systems in plants?
Flowering plants have evolved two separate mass transport systems:
The xylem transports water and mineral ions
The phloem transports sucrose and other nutrients
Why do plants not need a specialised transport system for oxygen and carbon dioxide?
They do not need one because:
They have adaptations that give them a high SA: V ratio for the absorption and diffusion of gases
The leaves and stems possess chloroplasts which produce oxygen and use up carbon dioxide
There is a low demand for oxygen due to plant tissues having a low metabolic rate
