Plants and Minerals Gr C: Explain the importance of Mg ions and N ions to plants. Gr B: Analyse the effects of magnesium and nitrate ions deficiency. Gr A: Create an investigation to test deficiency. Entrance Activity Discuss in groups how we can tell whether or not a plant is healthy or not? Key Words Magnesium ion Nitrogen ion Ammonium ion Fertiliser Deficiency Fertiliser A chemical used to enhance plant growth and/or health. Natural Fertiliser: Animal manure and compost. Artificial Fertiliser: NPK (N) Nitrogen (P)Phosphorus (K) Potassium What are the advantages of using fertilisers? • Fertilisers increase crop growth rate, producing a much healthier plant. • Improve total crop yield. What are the disadvantages of using fertilisers? • Fertiliser can affect the local habitat if it enters local streams and pools. • Causes algae blooms and increase the growth rate of some unwanted plants. Magnesium is absorbed from the soil as magnesium ions (Mg2+). Magnesium forms part of the chlorophyll molecule. What do you think will happen to the plant without magnesium and how do you think it will appear? Nitrogen is absorbed through the soil as nitrate ions (NO3-) or as ammonia ions (NH4+). Nitrogen is required for a lot of molecules in the plant, especially protein molecules. A deficiency in nitrogen causes the plant to have a stunned growth. The plant will also become extremely weak and the leaves can begin to wilt and die. Magnesium and Nitrogen In one paragraph, summarise all of the information regarding nitrogen and magnesium in plants. Try to include: • What each nutrient is used for. • How the plant changes with deficiency. Plants and Minerals Gr C: Explain the importance of Mg ions and N ions to plants. Gr B: Analyse the effects of magnesium and nitrate ions deficiency. Gr A: Create an investigation to test deficiency. Entrance Activity Discuss in groups how we can tell whether or not a plant is healthy or not? Key Words Magnesium ion Nitrogen ion Ammonium ion Fertiliser Deficiency Look at the plants below and write a conclusion of the results. Compare the full nutrient plant, the –Mg plant, and the – N plant. Which is the healthiest and why? Plants and Minerals Gr C: Explain the importance of Mg ions and N ions to plants. Gr B: Analyse the effects of magnesium and nitrate ions deficiency. Gr A: Create an investigation to test deficiency. Entrance Activity Discuss in groups how we can tell whether or not a plant is healthy or not? Key Words Magnesium ion Nitrogen ion Ammonium ion Fertiliser Deficiency Hydrogencarbonate indicator solution Hydrogencarbonate indicator solution responds to changing carbon dioxide levels in the environment. This can be used to see whether or not a plant requires Carbon dioxide for photosynthesis CO2 levels increase (pH drops) Starting colour CO2 levels decrease (pH rises) Independent variable: Light Levels Dependent variable: Rate of photosynthesis (measured by CO2 change) Control variables: Activities 1) Identify the different variables in the experiment shown above. 2) Illustrate the set up of the experiment in your books. 3) Make a prediction of what the test tubes will look like after three hours. Leaf size (mass) Volume of indicator Indicator starting colour Volume of air in test tube Plenary 1) What is hydrogen-carbonate used for? (1mark) 2) Describe two methods of measuring the amount of photosynthesis taking place? (2 marks) 3) What is the function of a palisade cell, and how is it adapted for its function? (2 marks) 4) What is an independent variable? (1 mark) 5) Which variables need to be controlled when testing how light affects the rate of photosynthesis. (3 marks)
