watch a creeper entwining its tendril to the support. Is not it? How do you express your feelings in this situation?
Plants also respond to external stimuli. How do you feel about this?
- A very interesting thing in plants is movement of tendrils.
- All plants show positive response to phototropism.
- But creepers like cucumber, bittergourd the stem is weak and thin. Hence plant cannot grow erect.
- Tendrils play a vital role to make the plant erect. Tendrils are thin thread-like growth on the leaves or stems of climbing plants.
- They grows towards support and wind around them.
- This type of response to make contact or touch is called thigmotropism.
- Nature only finds it’s way to grow and survive on the earth.
Hormones are released at a specific place, specific time for a specific function. Prepare a cartoon on the hormones with a nice caption.
Fill in the blanks.
- The largest region of the brain is ———–.
- A point of contact between two neurons is ———–.
- ———– phytohormone is responsible for cell elongation and differentiation of shoots and roots.
- Thyroxine is responsible for ———–.
- Gibberellins and auxins promote growth in plants while absciscic acid arrests the same. Some situations are discussed here. State which hormones would be needed and why?
a) A gardener wants large dahlias, he should use along with nutrients and other things ———– hormone.
b) In a dwarf plant the branches have to be thickened one would use the ———– hormone.
c) Seeds are to be stored a long time ———– hormone can help.
d) Cutting the apex or tip of plants so that there are several lateral buds ———– hormone can be used.
e) The part of the brain that helps you in solving puzzles is ———–.
- General growth rate and metabolic rate
- a) Auxin b) Gibberellin c) Absciscic acid d) Cytokinins e) Cerebrum
Choose the correct answer.
- A person has loss of control on emotions, which part of brain stops its function ? [ ]
C) Mid brain
- Leaf movement in mimosa helps to [ ]
A) Reduce photosynthesis
B) Protect from grazers
C) Releasing phytohormones
D) Regulate its growth
- Diabetes is related to this gland. [ ]
10th Class Biology 5th Lesson Coordination – The Linking System InText Questions and Answers
10th Class Biology Textbook Page No. 95
What helps us to respond to such signals?
There is a sequence of events that bring about responses. They start from detecting changes in environment.
Why does the living body respond to such signals?
The ability to react to particular stimulus in a particular situation must be of great importance in ensuring the survival of the organism.
10th Class Biology Textbook Page No. 96
What did Galen conclude after his observations?
After the observations of his patient, Galen a Greek physiologist concluded that nerves were of two types – those of sensation and those of action.
Why do you think Galen drew such a conclusion?
According to Galen the blow in the neck of his patient had damaged the nerves of sensation but had not affected its action. Then Galen concluded that nerves were of two types.
10th Class Biology Textbook Page No. 98
Which organ of our body was the detector and which was the effector in Activity -1?
In Activity -1, Eye was the detector and fingers were the effector.
What do you think that the information carried on the afferent and efferent nerves?
The information carried by afferent nerve is “scale is falling”.
The information carried by the efferent nerve is “to hold the scale”.
10th Class Biology Textbook Page No. 99
What other effectors would act under these circumstances?
- Withdraw our hands, when our fingers touch a hot object.
- Closing eyes when bright light is focussed on eyes.
- We sneeze when something enters the nose.
- We cough when inhaled dust or some other circumstances.
What does this tell us about the association nerves?
The sensory nerves in the spinal cord makes connections with other neurons in the grey matter. These neurons are called association neurons or interneurons. The association neurons process the information and generate responses.
10th Class Biology Textbook Page No. 100
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