2. The material in this slide show is provided free for educational use only. All other forms of storage or reproduction are subject to copyright- please contact the National Marine Aquarium The slide show was designed and produced for the NMA by STEP, the Science Training & Education Partnership T raining & S cience E ducation P artnership www.national-aquarium.co.uk www.step-up-to-science.com

3. How plants grow

4. Plants are the Producers in nearly all Food Webs - on land and in the ocean

5. Light and plant growthPlants in the oceanSummaryDividing cells

6. Light and plant growth Plants in the ocean Summary Dividing cells

7. Plants grow by photosynthesis They make their own food, using light and simple materials such as water

8. WATER LIGHTOXYGEN HYDROGEN CARBOHYDRATE CARBON DIOXIDE HYDROGEN STEP

9. WATER OXYGEN CARBOHYDRATE CARBON DIOXIDE LIGHT STEP

10. Photosynthesis uses light energy to turn carbon dioxide and water into carbohydrate The carbohydrate can be changed into other materials to make all the components of the plant cell Oxygen is produced as a waste product

11. The green colour of plants is caused by chlorophyll Chlorophyll absorbs the light used in photosynthesis

12. Light and plant growth Plants in the ocean Summary Dividing cells

13. On land, there is usually plenty of sunlight Trees grow tall trunks so that they can stand above other plants that might shade them

14. In the ocean, most light disappears in the top 100 metres Plants cannot grow deeper than this

15. Plants growing attached to the seabed, like this kelp, can only grow where the ocean is shallow enough to let through enough light for growth

16. Too dark for growth surface 100 m 500 m 1000 m 3500 m Enough light here for growth

17. 95% of the oceans are too deep for attached plants like kelp and seaweeds

18. Because rooted plants cannot grow over most of the oceans, the plants have to float close to the surface

19. The most important group of plants are microscopic plankton algae These are producers, just like land plants

20. But they look very different! This single celled plant is about one- fiftieth of a millimetre across

21. There may be one million of these tiny cells in each litre of surface seawater

22. Light and plant growth Plants in the ocean Summary Dividing cells

23. This can happen about once per day The tiny, single-celled plants in the ocean grow simply by dividing into two new cells

24. Starting with one cell, you have two after one day, and four on the second day

25. What will happen after a week? If the conditions are good for growth, the number of cells will double each day

26. DAY 1 1 cell

27. DAY 2 2 cells

28. DAY 3 4 cells

29. DAY 4 8 cells

30. DAY 5 16 cells

31. DAY 6 32 cells

32. DAY 7 64 cells

33. DAY 30 535 million cells If they could keep dividing at this rate for a month, there would be a huge number of algal cells!

34. If they did, they would soon run out of the other substances which they need for growth In reality, they cannot keep growing this fast for ever

35. Grazing animals can remove many of the new plant cells The cells also die, sink into the deeper parts of the ocean, or are eaten

37. Light and plant growth Plants in the ocean Summary Dividing cells

38. You have seen that - All green plants on land and in the sea are producers Plants grow by photosynthesis

39. Most of the ocean is much too deep for plants to grow on the bottom Plants in the open ocean are mainly single-celled plankton algae You have seen that -

40. Plankton algae can increase fast by dividing Grazing by animals stops the number of algae from getting very large You have seen that -

41. NOTES for USERS The material in this slide show is designed to support the teaching of science at Key Stage 1 A full description of the slide show, and linked activities for students, can be found on the National Marine Aquarium (NMA) web-site: Teachers are free to amend the slide show in whatever way they feel fit, or to use slides in other contexts. However, please note that neither the NMA nor the designers will accept responsibility for modifications, and original material remains copyright of the NMA Individual images used in the slides are copyright of NMA or STEP, except where acknowledged separately The slides have been set up to display as A4 landscape format. If they are incorporated into other slide sequences with different display settings, change in aspect ratio and text location will occur The slide sequence contains the minimum of effects and transitions. However, there are some automated animations, and teachers will wish to make sure that they are familiar with the sequence before use in class Use the PowerPoint notes viewer to obtain additional information for some slides www.justaddh2o.tv www.national-aquarium.co.uk