Chapter 9 - Transport in plants Flashcards
What is an xerophyte?
A plant that is adapted to conserve water in areas of low water availability
What is a hydrophyte?
A plant that copes with growing in permanent water bodies
What ways are plants adapted to be able to conserve water?
Having a thick waxy cuticle / sunken stomata / reduced stomata / reduced leaves / fallen leaves / hairy leaves / curled leaves
What is a root adaptation of xerophytes?
They have long roots that grow deep into the ground to access water that is deep underwater
What ways can xerophytes avoid low water availability?
Plants lose their leaves and become dormant or die, leaving seeds behind which can re-germinate and grow rapidly
What is a requirement for surface water plants?
Their leaves should float and be near the surface to get the light they require
What ways are hydrophytes adapted?
Thin or no waxy cuticle / lots of stomata which are always open / reduced structure / wide flat leaves / small roots / large SA on roots and stems underwater / air sacs / aerenchyma (packing tissue)
What is ad adaptation to plants that grow in areas of high water supply that may cause waterlogging (such as in mangrove swamps)
They grow aerial roots that grow upwards into the air which have many lenticels which allow for entry of air into the woody tissue
What are the needs for a transport system within plants?
Metabolic demands, plant size and SA: Vol ratio
What are the metabolic demands of a plant?
Ares of the plant that don’t photosynthesise need oxygen and glucose to be delivered to them and need their waste products to be removed, hormones and mineral ions also need to be transported.
Why does SA : Vol ratio cause demands in plants?
Multicellular plants need transport systems as their diffusion pathways are not efficient and can’t be relied on alone to supply cells with what they need
How does water help with the structure of a plant?
- Turgor pressure providing a hydrostatic skeleton to support the stem and leaves
- Turgor driving cell expansion
How does water help with the metabolism of a plant?
- Loss of water via evaporation helps to keep the plant cool
- Water is used to transport mineral ions (produced by photosynthesis) as an aqueous solution
- Water is a raw material for photosynthesis
What are the pores that allow for water to move into root hair cells?
Aquaporins
What are the two main pathways in plant cells?
Apoplast (through intercellular spaces in the cell wall - by cohesive forces) and symplast (through the cytoplasm and plasmodesmata - by osmosis)
