What are macro-nutrients and why are they called macro-nutrients?
Nutrients required in large quantities are called Macro-nutrients. They are six in number. Since they are required in large quantities, they are known as macro-nutrient. The six macro-nutrients required by plants are nitrogen, phosphorus, potassium, calcium, magnesium, and sulphur.
How do you differentiate between capture fishing, mariculture and aquaculture?
Explain any one method of crop production which ensures high yield.
How do good animal husbandry practices benefit farmers?
What are the desirable characters of bee varieties suitable for honey production?
How do plants get nutrients?
How are fish obtained?
What is genetic manipulation? How is it useful in agricultural practices?
What are the desirable agronomic characteristics for crop improvements?
What factors may be responsible for losses of grains during storage?
Which method is commonly used for improving cattle breeds and why?
Which of the following has more inertia: (a) a rubber ball and a stone of the same size? (b) a bicycle and a train? (c) a five-rupees coin and a one-rupee coin?
State the universal law of gravitation.
Which of the following are matter?
Chair, air, love, smell, hate, almonds, thought, cold, cold-drink, smell of perfume.
A force of 7 N acts on an object. The displacement is, say 8 m, in the direction of the force (Fig. 11.3). Let us take it that the force acts on the object through the displacement. What is the work done in this case?
What is meant by a pure substance?
How does the sound produced by a vibrating object in a medium reach your ear?
In a reaction, 5.3 g of sodium carbonate reacted with 6 g of ethanoic acid. The products were 2.2 g of carbon dioxide, 0.9 g water and 8.2 g of sodium observations are in agreement with the law of conservation of mass.
sodium carbonate + ethanoic acid → sodium ethanoate + carbon dioxide + water
What are canal rays?
State any two conditions essential for good health.
How is our atmosphere different from the atmospheres on Venus and Mars?
Distinguish between speed and velocity.
Why are sound waves called mechanical waves?
Identify the type of tissue in the following: skin, bark of tree, bone, lining of kidney tubule, vascular bundle.
What are the methods of preventing or reducing soil erosion?
What are canal rays?
Explain, why is it difficult for a fireman to hold a hose, which ejects large amounts of water at a high velocity.
Why is sound wave called a longitudinal wave?
Compare the properties of electrons, protons and neutrons.
What is the specific function of the cardiac muscle?
Give two practical applications of reflection of sound waves.