What is the difference between the manner in which movement takes place in a sensitive plant and the movement in our legs?
sensitive plants- they are sensitive to touch, mostly their leaves like a plant chui mui (shows quick fold inward or droop when we touch their leaves). And they do not have special proteins for the movement they show only growth pattern.
Movement in our legs:- this is a voluntary action which depends on our willingness. They have special protein and muscles to contract by which they are able to walk or run. The nerve impulses sends to the brain and the brain sends signals the various body parts for the voluntary or as well as involuntary actions.
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?
How does our body respond when adrenaline is secreted into the blood?
Which part of the brain maintains posture and equilibrium of the body?
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?
One-half of a convex lens is covered with a black paper. Will this lens produce a complete image of the object? Verify your answer experimentally. Explain your observations.
Why do acids not show acidic behaviour in the absence of water?
What are the necessary conditions for autotrophic nutrition and what are its by-products?
The image formed by a concave mirror is observed to be virtual, erect and larger than the object. Where should be the position of the object?
(a) Between the principal focus and the centre of curvature
(b) At the centre of curvature
(c) Beyond the centre of curvature
(d) Between the pole of the mirror and its principal focus.
The refractive index of diamond is 2.42. What is the meaning of this statement?
Describe the structure and functioning of nephrons.
How many 176 Ω resistors (in parallel) are required to carry 5 A on a 220 V line?
Draw the structure for the following compounds.
(i) Ethanoic acid (ii) Bromopentane*
(iii) Butanone (iv) Hexanal.
*Are structural isomers possible for bromopentane?
An object is placed at a distance of 10 cm from a convex mirror of focal length 15 cm. Find the position and nature of the image.
Explain the following terms with one example each.
(a) Corrosion
(b) Rancidity