What environmental challenges do terrestrial plants face? (6)
- risk of desiccation
- nutrient availability
- support
- regulation of gas exchange
- temperature fluctuation
- developing successful mechanisms for reproduction
What adaptations have animals made to living on land? (10)
- Living and growing only in moist settings
- Dormancy during periods of drought
- Resisting dessication by having waterproof other layer to reduce water loss
- The development of stomata to enable and regulate gas exchange and water loss
- Development of cortex and more highly specialised body parts such as roots, stems and leaves to carry out different functions
- Development of specialised vascular tissue; xylem and phloem, to transport water and nutrients throughout the plant.
- Incorporation of lignin into cell walls to give strength and support.
- Reproduction by means of seeds which are resistant to structures to protect the embryo, have an integral energy supply and can also function as a dispersal mechanism.
- Exploiting insects and other animals in pollination and seed dispersal mechanisms.
How many plant divisions are there?
What are they?
3
Division Bryophyta
Division Tracheophyta
Spermatophyes - angiosperms
Name 5 features of plants
- Multicellular
- Eukaryotic
- Cellulose
- Autotrophic
- Chlorophyll
Name an example of Bryophyta
Mosses
Describe mosses (6)
- Non-vascular
- Leaf-like structures
- No cuticle
- No stomata
- Contain rhizoids
- Contain spores
Describe the specialisation of mosses.
What do mosses lack?
Mosses lack specialisation.
Mosses do not have a vascular system, true roots, leaves, stems or a waxy cuticle.
What type of area do mosses inhabit?
Moist, shady areas.
How thick are mosses leaves?
Mostly 1 cell thick.
Without any vascular tissues, how do mosses support themselves?
They rely on the turgidity of their cells.
What are rhizoids?
Simple hair-like projections which grow out of the epidermal cells of the moss and also facilitate the uptake of water and mineral ions.
How do mosses reproduce? Spores or seeds?
Spores - these germinate after dispersal if they land somewhere where there is sufficient moisture.
Name 2 examples of division Tracheophyta and describe how they differ.
Tracheophyta = vascular plants
Ferns - non-seed bearing vascular plants (Pteridophyta)
Angiosperms (flowering plants) - seed-bearing vascular plants.
Describe ferns (Pteridophyta) (7)
- Vascular
- True roots, stems and leaves
- Cuticle
- Stomata
- Woody xylem
- Spores
- Rhizome = underground stem
Are vascular plants more adapted or less adapted than Byrophytes?
More adapted/evolutionised
What is the role of xylem in a plant?
What is the role of phloem in a plant?
Xylem - transport of water (stiffened by lignin)
Phloem - transport of sugars (non-lignified)
Describe the adaptations of spermatophytes (angiosperms) (7)
Describe their complexity.
- Vascular
- True roots, stems and leaves
- Leaves are broad and flat
- Cuticle
- Stomata
- Woody xylem
- Seeds
Further increase in complexity in comparison to ferns.
List xerophytic adaptations of plants. (6)
- Leaf curvature
- Sunken stomata
- Thick waxy cuticle
- Hairs
- Succulent tissue
- Reduced surface area
