Outline the wide diversity in the plant kingdom as exemplified by the structural differences between bryophytes, filicinophytes, coniferophytes and angiospermiophytes.
Bryophytes
Filicinophytes
Coniferophytes
Angiospermiophytes
No Roots, Vascular/ Cuticle
Roots, Leaves in Fronds 7 vascular system
Shrubs to very large trees
Roots, stems, leaves
Rhizoids= Root Hairs
Cuticle on leaves
Advanced vascular system
Advanced vascular system
Mosses= Simple Leaf Like Structure
Form small trees but not woody
Woody sterns and roots
Form woody tissue
Live Roots have flattened shape called thallus
Ferns
conifers
Flower Plants
Mosses & Liveworts
Draw a diagram to show the external parts of a named dicotyledonous plant including root, stem, leaf, axillary and terminal buds
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On the blog.....................
Draw a plan diagram to show the distrabution of tissues in the stem,root, and leaf of a generalized dicotyledonous plant
On the blog..............
Explain the relationship between the distribution of tissues in the leaf and the functions of these tissues
Phloem: Transports products of photosynethesis out of the leaf
Stoma: A pore that allows CO2 for photosynthesis to dissufuse in and O2 to diffuse out.
Guard Cells: this pair of cells can open or close the stoma and so control the amount of transpiaration
Upper Edpidermis: a continos layer of cells covered by a thick waxy cuticle. It prevents water loss from the upper surface even when heated by sunlight.
Lower Epidermis: is in cooler position and has a thinner waxy cuticle.
Spongy Mesophyll: consists of loosely packed rounded cells with few chloroplats. This tissue provides the main gas exchange surface so must be near the stomata in the lower epidermis
Palisade Mesophyll: consists of densely packed cylindrical cells with many chloroplats. This is the main photosynthetic tissue and is postion near the upper surface where the light intentisty is highest.
Outline four adaptations of xerophytes
-Spines instead of leaves- reduce rate of transpiration
-Thick stems- contain high amounts of water storage tissue
-Thick waxy cuticle
-Verticle stems- absorbs sunlight late and early but not midday when sun is too intense
-Wide branching and shallow root systems- absorb water closer to the surface that would be otherwise evaporated before reaching roots
Outline two structural adaptations of hydrophytes
-Air spaces in leaves- create buoyancy
-Small amounts of xylem in stem and leaf
-Stomata in upper epidermis
-Waxy cutice on upper surface of leaves
