IT’S A GREEN WORLD Plants need minerals too

Starter If you were growing geraniums in the lab, list the things they will need to grow well. Light, water, minerals What type of minerals? Nitrates, phosphates, potassium and magnesium

Plants need minerals too Learning objectives Success criteria Explain that mineral deficiencies result in poor plant growth Understand that fertilisers are added in improve crop yields Explain the uptake of minerals by active transport Be able to describe the effect of deficiency of certain minerals on plant growth Relate the information on packets of fertiliser to mineral content Show understanding of active transport by completing w/s B4d6

Not enough minerals! What happens if plants do not get enough minerals? Plants do not grow properly if they are deprived of minerals and begin to look unhealthy. If a plant does not get enough of a mineral it is said to have a mineral deficiency. Do mineral deficiencies affect a plant in the same way?

Mineral deficiency – no nitrogen! Nitrogen is used for making leaves and is probably the most important mineral for plant growth. What is the effect of nitrogen deficiency? upper leaves pale green lower leaves yellow and dead weak stem

Mineral deficiency – no phosphorus! Phosphorus is used for making roots and is important for all the other minerals used by plants. What is the effect of phosphorus deficiency? discoloured leaves small roots

Mineral deficiency – no potassium! Potassium is used for making flowers and fruit, so crops are given extra potassium before they start to fruit. What is the effect of potassium deficiency? poor flower and fruit growth discoloured leaves with dead spots

Mineral deficiency – no magnesium! Magnesium is used for making chlorophyll and so is vital for the process of photosynthesis. What is the effect of magnesium deficiency? upper leaves normal (leaves turn yellow from bottom upwards) lower leaves pale green or yellow

Task – Mineral deficiency Create a table to show the effects of the deficiency of the following minerals on plant growth: Nitrates Phosphates Magnesium Potassium Use p69 of the textbook to help you

Fertilisers 3:6:9 10kg The phosphorus content: By law the manufacturer of a product described as a ‘fertiliser’ must declare the nitrogen, phosphates and potash content on the package. Also any other nutrients that have been added to the product. The phosphorus content: This fertiliser contains 6% P2O5 (phosphates) 3:6:9 10kg NPK Fertiliser The nitrogen content: This fertiliser contains 3% N (nitrogen) The potassium content: This fertiliser contains 9% K2O (potash)

How do minerals enter plants? Like water, minerals enter plants through the roots. However, they do this by different methods. Water passively diffuses with a concentration gradient from the soil into the roots and up the stem. Minerals are usually found in the soil in lower concentrations than they occur in the plant. Why can they not be transported by diffusion? Diffusion cannot take place against a concentration gradient. Instead, minerals enter the roots by active transport.

What is active transport? Active transport uses energy from respiration to move substances against a concentration gradient. soil root hair cell Specific minerals from the soil enter through channels in the cell walls of the root hair cells. The minerals then travel around the plant in the xylem vessels. Plants may take up some minerals in the soil but not others. Why is it important that plants select which minerals to transport? mineral

Active transport

Task Complete B4d6 – Barley seedlings More sulfate ions are absorbed when oxygen is present (almost doubles) Respiration Respiration releases oxygen, which is needed for the active transport of mineral ions In soil, water and air occupy the same space; if there is too much water, there will be less, or not enough, air (oxygen) for respiration

Plenary Transporting minerals

Plants need minerals too Learning objectives Success criteria Explain that mineral deficiencies result in poor plant growth Understand that fertilisers are added in improve crop yields Explain the uptake of minerals by active transport Be able to describe the effect of deficiency of certain minerals on plant growth Relate the information on packets of fertiliser to mineral content Show understanding of active transport by completing w/s B4d6