al cord is to act as a relay station – receiving information from various parts of the body parts below the head and send this information to the brain.
- Similarly, it receives information from brain and sends this information to other parts of the body.
- In addition to this, spinal cord also plays a major role in the RFELEX ACTIONS.
- The message received from the sensory nerve is passed into spinal cord. It is analyzed by the INTER NEURON present in the spinal cord and response is given. It is conveyed to the effector organ through motor nerve. The effector organ shows the response.
- Thus spinal cord saves us from dangerous stimuli through it’s REFLEX ACTIONS.
Draw a picture representing connection between dendrite – dendrite, axon – dendrite. Why do they connect like that?
- The nerve cell is the structural and functional unit of nervous system.
- It consists of more than 100 billion of them, which communicate with each other in a specific manner.
- Dendrites of one nerve cell connects to the other or to the axons of another nerve cell through connect points called as a synapse.
Draw a neatly labelled diagram of Brain and write few points how it is protected.
Protection of Brain :
- Brain is present in the hard bony box called CRANIUM.
- It is covered by three layers called MENINGES.
- The space between the inner layer is filled with fluid called cerebrospinal fluid,
- It serves a shock-absorbing medium and protects brain against shocks/ jerks along with the meninges and cranium.
You are walking in the traffic suddenly you heard a loud sound. How does coordination take place in this situation among respected organs? Draw a block diagram to explain this situation.
Make a model of neuron using suitable materials.
Required materials: A chart, twine thread, fevicol, sticker.
Observe different actions performed by your classmate for a period of 45 minutes. Out of these actions which are controlled by voluntary and involuntary pathways?
- carrying books
- Blinking of eyes
- listening etc.
Its very interesting to 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 phytohormon