What is the function of receptors in our body? Think of situations where receptors do not work properly. What problems are likely to arise?
Receptors are transducers which exhibits sensitivity in various body parts. When our body receives any external or internal stimuli, it converts stimuli into nerve impulses (action potential) and send these impulses to other neurons, muscle fibres or glands.
If the receptors get damaged they will not detect the stimulus, as well our brain also will not detect the signals which will be harmful for our body (Eg. When we touch an cold or hot object or to getting burnt etc.)
Draw the structure of a neuron and explain its function.
Which signals will get disrupted in case of a spinal cord injury?
How does chemical coordination take place in animals?
Compare and contrast nervous and hormonal mechanisms for control and coordination in animals.
Why is the use of iodised salt advisable?
The brain is responsible for
(a) thinking.
(b) regulating the heart beat.
(c) balancing the body.
(d) all of the above.
How do we detect the smell of an agarbatti (incense stick)?
How do auxins promote the growth of a tendril around a support?
Which part of the brain maintains posture and equilibrium of the body?
How does our body respond when adrenaline is secreted into the blood?
Did Döbereiner’s triads also exist in the columns of Newlands’ Octaves? Compare and find out.
What is a good source of energy?
Why is diffusion insufficient to meet the oxygen requirements of multi-cellular organisms like humans?
What are trophic levels? Give an example of a food chain and state the different trophic levels in it.
What changes can you make in your habits to become more environment-friendly?
What is the importance of DNA copying in reproduction?
If a trait A exists in 10% of a population of an asexually reproducing species and a trait B exists in 60% of the same population, which trait is likely to have arisen earlier?
Why should a magnesium ribbon be cleared before burning in air?
Define the principal focus of a concave mirror.
You have been provided with three test tubes. One of them contains distilled water and the other two contain an acidic solution and a basic solution, respectively. If you are given only red litmus paper, how will you identify the contents of each test tube?
You have two solutions, A and B. The pH of solution A is 6 and pH of solution B is 8. Which solution has more hydrogen ion concentration? Which of this is acidic and which one is basic?
Food cans are coated with tin and not with zinc because
(a) zinc is costlier than tin.
(b) zinc has a higher melting point than tin.
(c) zinc is more reactive than tin.
(d) zinc is less reactive than tin.
What are the differences between the transport of materials in xylem and phloem?
Explain the following in terms of gain or loss of oxygen with two examples each.
(a) Oxidation
(b) Reduction
A doctor has prescribed a corrective lens of power +1.5 D. Find the focal length of the lens. Is the prescribed lens diverging or converging?
In the Modern Periodic Table, which are the metals among the first ten elements?
What are the components of the transport system in human beings? What are the functions of these components?
Can you suggest some changes in your school which would make it environment-friendly?
Why are the small numbers of surviving tigers a cause of worry from the point of view of genetics?
How has the traditional use of wind and water energy been modified for our convenience?