Give an example of a plant hormone that promotes growth.
Auxin is a plant hormone produced in stem tips that helps in cell elongation or expansion. Auxin also helps in the process of phototropism by binding, which helps the plant to grow towards light direction.
Also shows more physiological effects like cell differentiation (shows relative amount of xylem and phloem), inhibits root elongation 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?
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?
Define the following terms.
(i) Mineral (ii) Ore (iii) Gangue
How much energy is given to each coulomb of charge passing through a 6 V battery?
Why should curd and sour substances not be kept in brass and copper vessels?
What will be the formula and electron dot structure of cyclopentane?
What are the different ways in which glucose is oxidised to provide energy in various organisms?
Translate the following statements into chemical equations and then balance them.
(a) Hydrogen gas combines with nitrogen to form ammonia.
(b) Hydrogen sulphide gas burns in air to give water and sulpur dioxide.
(c) Barium chloride reacts with aluminium sulphate to give aluminium chloride and a precipitate of barium sulphate.
(d) Potassium metal reacts with water to give potassium hydroxide and hydrogen gas.
Will current flow more easily through a thick wire or a thin wire of the same material, when connected to the same source? Why?
Will geographical isolation be a major factor in the speciation of an organism that reproduces asexually? Why or why not?
What is the role of the acid in our stomach?
How does binary fission differ from multiple fission?