Respiration And Photosythesis - 3rd Year Flashcards
Show the word equation for photosynthesis.
Sunlight
Carbon dioxide + Water —————> Glucose + Oxygen
Chlorophyll
Draw a diagram of a plant showing where all the materials are input and all the products are released.
Draw diagram (on revision sheet)
Describe an experiment to show how a leaf can be tested for starch.
- Place the leaf in boiling water for 30 seconds.
- Then place the leaf in boiling ethanol.
- Then dip the leaf in water.
- Finally spread the leaf onto a white tile and add iodine to test for the presence of starch.
Describe an experiment to show how the intensity of light affects the rate of photosynthesis.
Place a piece of pond weed in a beaker of water below a funnel. After, place a strong light close to the plant. You should notice bubbles of gas escaping. The closer the light is, the greater the number of bubbles.
Describe an experiment that show what factors affect germination.
Prepare 4 test tubes with 10 cress seeds in cotton wool, Labeled A,B, C and D.
For tube A: Keep the cotton wool dry
For tube B: Moisten the cotton wool with water
For tube C: Cover the seeds and cotton wool with water and add a layer of oil on top
For tube D: Moisture the cotton wool and place the tube in a Fridge (19*C)
Keep tubes A,B, at room temperature. After 3-5 days, ensure the cotton wool in tubes B and D stay moist. Compare the number of germinated seeds in each tube.
Describe an experiment to show how the direction of light affects plant growth.
Phototropism is the way a plant changes how it grows due to light. The shoots of the plant grow towards the light. This is controlled by hormones in the plant. We can show this by growing some seeds in a box with a small hole on one side, The plants will grow towards the light.
Describe the word equation for respiration.
Glucose + Oxygen ————> Carbon Dioxide + Water + Energy
Describe how respiration is different to breathing.
Breathing is the inhalation of Oxygen and exhalation of carbon dioxide and water by your lungs whereas respiration is a chemical reaction that happens in every cell in the body using food and Oxygen to produce energy. It is defined as the release of energy from food.
Describe an experiment to show how temperature affects the rate of respiration.
Yeast is added to a sugar solution and the gas is collected. The higher the temperature the greater the amount of Carbon Dioxide collected. The rate of respiration increases with temperature.
