Design an experiment to demonstrate hydrotropism.
Hydrotropism is a part of tropism process that shows in plants. The growth and movement of plant roots towards or away from moisture is hydrotropism.
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?
What kind of mirror – concave, convex or plain – would be best suited for use in a solar cooker? Why?
What processes would you consider essential for maintaining life?
What are the advantages and disadvantages of using a solar cooker? Are there places where solar cookers would have limited utility?
Compare and contrast fossil fuels and the Sun as direct sources of energy.
Why is vegetative propagation practised for growing some types of plants?
What determines the rate at which energy is delivered by a current?
What would be the electron dot structure of carbon dioxide which has the formula CO2?
What are the limitations of extracting energy from—
(a) the wind? (b) waves? (c) tides?
How is a voltmeter connected in the circuit to measure the potential difference between two points?
Two conducting wires of the same material and of equal lengths and equal diameters are first connected in series and then parallel in a circuit across the same potential difference. The ratio of heat produced in series and parallel combinations would be –
(a) 1:2 (b) 2:1 (c) 1:4 (d) 4:1