RHS Level 2 Certificate week 11 overview

2,554 views
2,339 views

Published on

Published in: Education, Technology
0 Comments
0 Likes
Statistics
Notes
  • Be the first to comment

  • Be the first to like this

No Downloads
Views
Total views
2,554
On SlideShare
0
From Embeds
0
Number of Embeds
13
Actions
Shares
0
Downloads
67
Comments
0
Likes
0
Embeds 0
No embeds

No notes for slide

RHS Level 2 Certificate week 11 overview

  1. 1. RHS Level 2 Certificate Week 11 – Plant growth, development and control
  2. 2. Christmas Prize Quiz <ul><li>Test conditions </li></ul><ul><li>30 minutes </li></ul><ul><li>Ho! Ho! Ho! </li></ul>
  3. 3. Learning Outcomes <ul><li>State what is understood by growth and development. </li></ul><ul><li>State that simple cell division produces growth and results in an increase in size. </li></ul><ul><li>Describe how competition for water, nutrients, light and space can influence growth. </li></ul><ul><li>Describe two examples of how auxin influences plant growth. </li></ul><ul><li>Describe what is meant by the term phototropism. </li></ul><ul><li>Define the term: ‘photoperiodism’. </li></ul>
  4. 4. Review of growth <ul><li>Takes place by mitosis </li></ul><ul><li>At the meristems </li></ul><ul><li>Meristems – vascular cambium, cork cambium, apical meristem, pericycle </li></ul>
  5. 5. Growth and Development <ul><li>Growth and development – what is the difference? </li></ul><ul><li>Plant growth = increase in size. </li></ul><ul><li>Plant development = maturation of plant, formation of plant organs such as flowers etc. </li></ul>
  6. 6. Competition and growth <ul><li>Key factors required for growth are sufficient light, water, nutrients, oxygen and carbon dioxide and suitable temperature. </li></ul><ul><li>Competition means these may not be available to plants </li></ul><ul><li>Use of plant spacing in horticulture to provide optimum conditions for growth </li></ul><ul><li>Competition may mean death or reduced size or yield </li></ul>
  7. 7. Plant Growth Regulators 1 <ul><li>Control the way in which plants grow. For example that roots grow downwards and shoots upwards. </li></ul><ul><li>Chemicals produced by the plant which control the speed and location of the division of cells and the differentiation of those cells once produced </li></ul>
  8. 8. Plant Growth Regulators 2 <ul><li>Auxin stimulates plant cells to increase in length especially near to stem and root tips. It also promotes fruit formation </li></ul><ul><li>Cytokinins promote cell division (mitosis) and delay the senescence of leaves. </li></ul><ul><li>Gibberellins promote cell division and elongation of the stem. They also promote flowering and bolting in ‘long day’ plants and seed germination. </li></ul><ul><li>Ethylene promotes ripening of fruit and senescence of leaves and flowers. Induces abscission of leaves in deciduous plants (the process of leaf fall). </li></ul><ul><li>Abscisic acid maintains dormancy in seeds and possibly in buds. It also is responsible for causing the closing of stomata </li></ul>
  9. 9. Auxin and tropisms <ul><li>Tropisms are growth responses to external stimuli </li></ul><ul><li>Phototropism – plants grow toward the light </li></ul><ul><li>Geotropism – may be positive (growth towards gravitational pull) or negative (growth away) </li></ul><ul><li>Thigmatropism – growth towards touch. </li></ul><ul><li>Auxin migrates in the stem to cause cell elongation that causes the above growth responses </li></ul>
  10. 10. Day length and growth <ul><li>The growth responses of plants to the length of day light hours is called photoperiodism. </li></ul><ul><li>Triggers flowering, leafy growth, formation of bulbs and tubers etc in some species </li></ul><ul><li>Day Neutral plants are not affected by day length </li></ul><ul><li>Short Day plants – flower when the day length is short (night is long). </li></ul><ul><li>Long Day plants – flower when the day length is long (night is short) </li></ul>
  11. 11. Learning outcomes <ul><li>State what is understood by growth and development. </li></ul><ul><li>State that simple cell division produces growth and results in an </li></ul><ul><li>increase in size. </li></ul><ul><li>Describe how competition for water, nutrients, light and space can influence growth. </li></ul><ul><li>Describe two examples of how auxin influences plant growth. </li></ul><ul><li>Describe what is meant by the term phototropism. </li></ul><ul><li>Define the term: ‘photoperiodism’. </li></ul>
  12. 12. Term Dates <ul><li>Happy Christmas! </li></ul><ul><li>Classes start again on the 13 th January </li></ul><ul><li>Happy homework! </li></ul>

×