1. Plant Hormones

2. Can you explain what is happening. Click to reveal the answer. Plant sensitivity The animation shows the growth of a young shoot towards the light.

3. Plant sensitivity The auxins diffuse down the shoot and cause cells behind the tip to elongate. There is greater growth on the shady side of the young shoot. The shoot grows towards the light - this is known as PHOTOTROPISM. Auxins are produced in the shady side of the tip. The animation shows the growth of a young shoot towards the light. Can you explain what is happening. Click to reveal the answer.

4. Experiments Predict what will happen in each of these experiments. Click on each shoot to show its growth response. Normal young shoot Tip removed from shoot Tip covered with a foil cap Tip removed and replaced with an agar block containing auxin Tip removed and replaced on one side with a small agar block containing auxin

5. Can you explain the use of hormones in each diagram. Click to reveal the answer. Applications of plant hormones

6. Can you explain the use of hormones in each diagram. Click to reveal the answer. Fresh fruits are shipped around the world. Plant hormones are used to slow the ripening of the fruit, so they are just ripe as they reach the supermarket. Applications of plant hormones

7. Can you explain the use of hormones in each diagram. Click to reveal the answer. Applications of plant hormones

8. When a gardener takes cuttings from a plant, the base of each cutting is first dipped into a rooting compound to stimulate the growth of roots. Many rooting compounds contain auxin. Can you explain the use of hormones in each diagram. Click to reveal the answer. Applications of plant hormones

9. Can you explain the use of hormones in each diagram. Click to reveal the answer. Applications of plant hormones

10. Auxins can be sprayed onto flowers so that the fruits develop without pollination or fertilisation. These fruits are seedless. Can you explain the use of hormones in each diagram. Click to reveal the answer. Applications of plant hormones

11. Can you explain the use of hormones in each diagram. Click to reveal the answer. Applications of plant hormones

12. Weeds have broader leaves than the grass on a lawn. The weeds will take up more auxin than the grass when the lawn is sprayed. Can you explain the use of hormones in each diagram. Click to reveal the answer. Auxins can be used as herbicides. The weeds will grow too quickly and die.

13. True or false? Gardeners prune to create bushier plants. This is because pruning causes plants to create... 1. more auxin and this enables side shoots to grow 2. less auxin and this enables side shoots to grow 3. more auxin and this inhibits side shoots from growing 4. less auxin and this inhibits side shoots from growing Which of the following statements is true? Click to reveal the answer.

14. True or false? Gardeners prune to create bushier plants. This is because pruning causes plants to create... 1. more auxin and this enables side shoots to grow 2. less auxin and this enables side shoots to grow 3. more auxin and this inhibits side shoots from growing 4. less auxin and this inhibits side shoots from growing Which of the following statements is true? Click to reveal the answer.

15. True or false? Young roots always grow downwards. This is because roots are... 1. positively phototropic 2. negatively hydrotropic 3. positively geotropic Which of the following statements is true? Click to reveal the answer.

16. True or false? Young roots always grow downwards. This is because roots are... 1. positively phototropic 2. negatively hydrotropic 3. positively geotropic Which of the following statements is true? Click to reveal the answer.

17. Plant Hormones The End R Heppell 2000 Beauchamp College Biology Department