| A | B |
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| Name a stimuli for plants | light, humidity, temperature |
| What are the most frequent reactions of plants | tropisms, nastic movements, and changes in the plant´s vital processes. |
| What are tropisms? | plant responses which consist of directing their growth towards, or away from stimulus. |
| What is phototropism? | a response to light |
| Give an example of a phototropìsm | the shoots of a plant growing towards the light, the roots of a plant growing towards the dark. |
| What is geotropism? | a response to gravity. |
| Give an example of geotropism | toots growing towards the earth. |
| What is Hydrotropism? | the response to the presence of water |
| Give an example of hydrotropism | the roots of a plant growing torwards water in the soil |
| What is Thigmotropism? | the response to contact |
| Give an example of Thigmotropism | in the shoots of creepers, which grow around the objects they touch |
| What are Nastic Movements? | Plant responses which consist of rapid movements of some parts. They are usually reversible. |
| Give two examples of Nastic Movements | Photonasty and Thigmonasty |
| What is Photonasty? | It is the response to light. |
| Give an example of Photonasty | The way leaves or flowers turn, following the sun, or the opening and closing of some flowers depending on whether it is day or night. |
| What is Thigmonasty? | It is the response to contact. |
| Give an example of Thigmonasty | The mimosa shrub folds its leaves when it is touched. THe flytrap, a carnivorous plant, snaps its leaves shut when an insect brushes against it. |
| Some plants react to stimuli by modifying some of their vital processes. Give an example | seasonal changes of many plants, like responses to temperature, light, or the length of day and night (flowering in spring, shedding leaves in autumn, fruits maturing in summer) |
| The sun is positioned directly above the plant, it´s 3:00 pm. What reaction will the plant have when it is 7:00pm? | The leaves will turn to face where the sun is, the west. |
| What is the normal tropism of a plant? | When a seed germinates, the root grows down and the stalk grows upwards. |
| What happens to a plan in terms of tropism if we place a plant horizontally? | The stalk grows upward and the root down (due to gravity) |
| How does temperature affect a tree´s vital processes? | In January, at below 0 degrees, the tree is dormant, with no leaves. In April, with temperatures in the 10 to 13 degree range, it begins to flower. In June and July when temperatures peak at 23 degrees the fruit of the tree matures. In September as the temperature falls to about 12 degrees, the leaves turn color and fall. In December as tempertures drop down again, the tree repeats it´s cycle. |
