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RHS Level 2 CertificateYear 1 Week 3
More roots, shoots and leaves.
Learning outcomes
1. Roots (2) 1.3.4 Describe how the root is adapted in order to perform specific functions. 1.3.5 Root fungi and bacteria- symbiosis 2. Stems – structure and purpose 2.1 Describe how the stem develops. 2.2 Describe different types of buds and state where they occur in the plant. 2.3 Identify the two elements of the vascular system and name their purposes 2.4 Describe how the stem is adapted in order to perform specific functions. 3. Leaves – structure and purpose 3.1 Describe the structure of the leaf. 3.2 Describe how leaf shape, size, form and colour can vary. 3.3 Describe how leaves are adapted in order to perform certain functions 4. Plant file – plant identification from week 2 and introduce 3 new plants.
Roots (2)
Symbiosis – what is it? How does it work? Mycorrhizal fungi – what are they? How are
they used in horticulture? Nitrogen fixing bacteria – what are they?
How do gardeners take advantage of them?
Stems – Structure and Purpose
What are stems for? What is the internal structure of the stem?
– Stem vascular system– Differences between stem and roots– Differences between monocot and dicot stems.
Buds – different types
Apical bud – at the tip of the shoot. What is apical dominance? How can this be manipulated by gardeners?
Axillary buds – at the joint between leaf and stem (at the node). Usually dormant or leaf producing.
Stem Adaptations
Water storage – e.g. Opuntia sp. Thorns for protection - Crataegeus
monogyna (Common Hawthorn) Dormancy – storing food to allow avoidance
of hostile conditions over winter or during summer drought e.g. Zingiber officinale (Ginger ) has a rhizome, Solanum tuberosum ssp. Tuberosum (potato) has stem tubers
Leaves –function and structure (1)
Function of leaves – photosynthesis External structure
– Petiole– Lamina– Midrib– Veins
Leaves –function and structure (2)
Internal structure
Cuticle Epidermis
Palisade cells Chloroplasts
Spongy mesophyll Stomata
Phloem Xylem
Leaf Adaptations
Tendrils – for climbing e.g. Lathyrus odoratus Leaf Hairs – for protection from the sun e.g.
Stachys byzantina Spines – for protection from grazing animals
e.g. Ilex aquifolia Food storage – for over-wintering, e.g.
Narcissus spp.
Leaf adaptations (2)
Leaf fall for deciduous trees – formation of abscission layer; recovery of chemical components of chlorophyll; leaf fall.
Leaf form and leaf arrangement (phyllotaxy)
Various different leaf forms – known by different descriptive names to enable clear identification
Phyllotaxy is the name for the arrangement of leaves on a plant. Prevents the leaves from shading each other.
Learning outcomes
1. Roots (2) 1.3.4 Describe how the root is adapted in order to perform specific functions. 1.3.5 Root fungi and bacteria- symbiosis 2. Stems – structure and purpose 2.1 Describe how the stem develops. 2.2 Describe different types of buds and state where they occur in the plant. 2.3 Identify the two elements of the vascular system and name their purposes 2.4 Describe how the stem is adapted in order to perform specific functions. 3. Leaves – structure and purpose 3.1 Describe the structure of the leaf. 3.2 Describe how leaf shape, size, form and colour can vary. 3.3 Describe how leaves are adapted in order to perform certain functions 4. Plant file – plant identification from week 2 and introduce 3 new plants.