Download Plant Hormones Video Questions

Coordination & Control 2: Plants
During the Program
1. What are 3 differences between plants and animals responses to environmental change?
2. What is a tropism? What is the difference between positive and negative tropisms?
3. What is the difference between a tropism and a nastic response? What causes nastic
responses?
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4. What is a plant hormone. How do they travel around the plant?
5. List the five main groups of plant hormones.
6. What experiments established the following:
a) That the substance that causes bending in oat coleoptiles is produced in the
coleoptile tip.
b) That a substance or substances travelling down the side of the shoot, away from the
light, causes bending of oat coleoptiles.
7
What is thought to be the effect of auxin on cell walls?
8
What is apical dominance?
9
What 2 cellular processes do Gibberellins stimulate?
10 Where are cytokinins found? How do they travel through a plant?
11 Give 2 possible roles of cytokinins.
12 Give one suggestion of how they are thought to work in conjunction with auxins.
13 In tissue differentiation what do cytokinins control? What about auxin?
14 Why is abscisic acid sometimes called the plant stress hormone?
15 How did ABA get its name? What are its correct roles?
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NOTE: this research is relatively new and has not been substantiated, therefore we
should still learnt that ABA causes the production of the abscission layer in leaves and fruits.
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ABA also causes plants to become dormant eg in winter, regulates the opening and
closing of the stomata
16 How is ABA used in commercial nurseries?
17 What hormone reverses dormancy?
18 How was the effect of ethylene on plants first noticed?
19 List the effects of ethylene.
20 What application does this have for fruit producers and distributors?
Test your Understanding Questions
Multiple Choice Questions
1. Tropism:
A. is the loss of water through the leaves of a plant
B. occurs when a plant moves in response to a stimulus
C. is the wilting that occurs when a plant receives insufficient water
2. A plant tropism where the plant responds towards a stimulus is:
A. positive
B. negative
C. unreliable
3. The growth of plant roots towards the earth is:
A. geotropism
B. gravitropism
C. both of the above
4. Auxins responsible for phototropism are produced in the shoot tip called the:
A. xylem
B. root hairs
C. coleoptile
5. The response of certain plants to touch is:
A. thigmotropism
B. geotropism
C. phototropism
6. Elongation of cells is produced by hormones called:
A. insulin
B. auxins
C. both of the above
True-False Questions
7. Positive phototropism is the bending of a plant towards light. T / F
8. The growth of a plant shoot away from the earth is positive geotropism.
9. The only plant hormones are auxins. T / F
T / F
Short Answer Questions:
1. What is the difference between plant and animal hormones?
2. What makes the way that ethylene acts on plant cells different from all other plant
hormones?
3. The ripening of fruit is associated with the gas ethylene, which increases the rate of
enzymes such as amylase that convert starch into simple sugars. The ripening of fruit is
also linked to oxygen consumption.
a. Oxygen is consumed by plants regardless of whether fruit is ripening, why?
b. Why do plants breakdown starch into simple sugars as part of the fruit ripening
process?
4. When a seed is planted in the soil what type of tropism do the roots display? Why?
5. Which hormone is likely to be found in high concentrations during a drought? Why?
6.
A student set up a series of experiments by covering various parts of the stem to
determine the role of sunlight in plant growth.
A
B
C
D
E
F
a. Which of the plants above would bend towards the light?
b. Why wouldn’t all of the plants bend towards the light?
c. Which hormone is responsible for the growth being monitored in this experiment?
d. Outline what causes the plants to bend towards the light.
7.
a. Auxins are thought to be involved in apical dominance, design an experiment to
test this hypothesis. Use the space below to draw the set-up.
b. What your expected results be in the experiment designed in part a?