Plants and Photosynthesis

1. Plants and Photosynthesis

2. Parts of a plant • Root is for anchorage and uptake of water and minerals. • Stem supports the rest of the plant and contains the vascular bundles (xylem which moves water around the plant) (phloem which moves sugars around the plant).

3. Parts of a plant • Leaf this is where sunlight turns water and carbon dioxide into glucose and oxygen in the presence of chlorophyll. • Flower is where pollination takes place and seed production occurs. This ensures the life cycle of the plant continues.

4. Photosynthesis Water + Carbon dioxide+Sun= Glucose + Oxygen + Energy

5. Testing for Starch • The glucose in the leaf combines to form long chains. • The long chain formed is starch. • If we boil the leaf in alcohol it decolorizes. • Then to detect starch we place iodine on to the leaf if it goes blue / black if starch is present.

6. The Starch • The starch is used by the plant for growth, storage and respiration. • Growth ~ starch can be used to make cellulose which is found in cell walls. • Storage ~ the starch can be moved to the roots in crops like potato, carrot and turnip. • When plants make glucose they use it with the oxygen to produce energy in the plant cells. This is called respiration.

7. The Flower The stamen is the male reproductive part. The anther makes tiny grains called pollen, which contain male sex cells. The filament holds up the anther. Petal Anther Filament

8. The Flower Petal The Carpel is the female reproductive organ. The Stigma is the top part of carpel with sticky surface to trap pollen. The Style joins stigma to the ovary. The Ovary contain the female sex cell called the Ovule. Stigma Style Ovary Ovule

9. Water and Plants • Plants obtain the water they need from the soil. It enters the root hairs and passes through the root system by a process called DIFFUSION. • Osmosis is defined as the flow of water across a selectively permeable membrane from a weak solution (lots of water). To a strong solution (small amount of water).

10. Water and Plants • The pressure of the water entering the root pushes the water up the stem through the tubes called the xylem. Water is carried by the stem xylem and into the leaves the leaves by a sucking force from above caused by water molecules leaving the stomata. • This process is called Transpiration

11. Root hair cell Root hair • Water is taken up from the soil into the root hair. • The root hair is very thin and it has a very large surface area. Water

12. Cross section of stem • The outer green circle represents the outer stem. • The inner yellow circle represents the cortex tissue. • The red zones are the xylem vessels. • The blue zones are the phloem vessels. • The inner green zones are the cambium. • The red, green and blue zone are called the vascular bundles.

13. Photosynthesis • Photosynthesis is where carbon dioxide and water are changed into glucose and oxygen in sunlight by the chlorophyll inside the chloroplast.

14. Respiration • Respiration takes place day or night. • The glucose and oxygen products from photosynthesis are used to produce energy in the cells. • The products of respiration are carbon dioxide and water.

15. Lungs of the World • Plants produce oxygen and are sometimes called the lungs of the world. • This is a poor explanation of how they work. • They take water and carbon dioxide and produce glucose and oxygen for the plant. The excess oxygen is passed into the atmosphere for animals to breathe.

16. No Green plants • Without green plants life on this planet would cease to exist. • Animals cannot survive without oxygen. • Then new plants could not survive without carbon dioxide from animals.