A squirrel is in a scary situation. Its body has to prepare for either fighting or running away. State the immediate changes that take place in its body so that the squirrel is able to either fight or run?
A squirrel is in a scary situation. Its body has to prepare for either fighting or running away. State the immediate changes that take place in its body so that the squirrel is able to either fight or run?
Chemical communication is superior to electrical impulses as a cellular communication mechanism in multicellular organisms for the following reasons:
- Wider Reach: Electrical impulses can only reach cells that are directly connected by nervous tissue. Chemical signals (like hormones) can diffuse or travel through body fluids to reach each and every cell of the organism, regardless of nervous connections.
- Continuous Signaling: After transmitting an electrical impulse, a nerve cell requires time to reset its chemical and electrical mechanisms before it can generate another impulse. Cells cannot transmit electrical impulses continuously. Chemical communication does not have this limitation and can provide steady, persistent signaling.
- Targeted and Coordinated Response: Chemical compounds diffuse around the source, and any cell with specific receptor molecules on its surface can detect and respond to the signal. This allows for highly coordinated, long-lasting, and widespread physiological changes.
Marking Scheme
- 1Explaining that electrical impulses only reach cells connected by nervous tissue, while chemical signals can reach all cells: 1 Mark
- 2Explaining that cells need time to reset after an electrical impulse, whereas chemical signaling allows continuous transmission: 1 Mark
- 3Explaining that chemical signals diffuse and are detected by specific receptors, enabling coordinated and persistent responses: 1 Mark
Hint
Consider the limitations of electrical impulses: do they reach every cell? Can a cell transmit them continuously without a break?
Quick Oral Answer
Chemical communication is better because electrical impulses only reach cells connected by nerves and require cells to reset before sending another impulse. Chemical signals can reach all cells and provide continuous, coordinated responses.
Analysis & Explanation
While electrical impulses are extremely fast, they have significant limitations in multicellular organisms: they are restricted to wired pathways (nerves) and require a refractory period (resetting time). Chemical communication overcomes these limitations by utilizing chemical messengers (hormones or neurotransmitters) that diffuse through tissues or travel via the circulatory system. This allows plants (which lack a nervous system) and animals to coordinate complex, long-term processes like growth, development, and metabolic regulation across the entire body.
Common Mistakes
- 1Only mentioning that plants don't have nerves, without explaining the cellular limitations of electrical impulses in animals.
- 2Failing to mention the 'resetting time' or refractory period of nerve cells.
- 3Not mentioning that electrical impulses cannot reach every single cell of the body.
Interesting Facts
Plants rely entirely on chemical communication (phytohormones) because they lack any nervous system, allowing them to coordinate complex directional growth (tropisms) in response to light, gravity, and water.
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Frequently Asked Questions
How many marks does this question carry in CBSE Class 10 Science 2020?
This question carries 3 marks in the CBSE Class 10 Science 2020 examination.
Which chapter does this question come from in Science?
This question is from the chapter "Control and Coordination" in the CBSE Class 10 Science syllabus.
What topic does this question cover in Science?
This question covers the topic "Chemical Communication" from CBSE Class 10 Science.
What type of question is this in the CBSE Class 10 Science 2020 paper?
This is a Short Answer question from Section B in the CBSE Class 10 Science 2020 paper.