Case study ( 4 Marks )

Question 14 Marks

Read the following text carefully and answer the questions that follow:
Mixtures are constituted by more than one kind of pure form of matter. Sodium chloride is itself a pure substance matter. The solution is a homogeneous mixture of two or more substances. Lemonade, soda water etc. are all examples of solutions. Alloys are mixtures of two or more metals or a metal and a non-metal and cannot be separated into their components by physical methods. A solution has a solvent and a solute as its components. The component of the solution that dissolves the other component in it (usually the component present in a larger amount) is called the solvent. The component of the solution that is dissolved in the solvent (usually present in lesser quantity) is called the solute.

i. In a water-sugar solution: Identify solute and solvent?
ii. What is the size of the particles of a solution?
iii. What is pure substance?
OR
What do you mean by Alloy?

Answer

i. Water is solvent and sugar is solute.
ii. 1 nm in diameter
iii. Pure substances are substances that are made up of only one kind of particle and have a fixed or constant structure.
OR
The meaning of the term 'alloy' is a substance formed from the combination of two or more metals. Alloys can also be formed from combinations of metals and other elements. ex- steel.

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Question 24 Marks

Read the following text carefully and answer the questions that follow:
A farmer has grown wheat on his field consecutively two times but when the third time he grows wheat on the same field the quality of the wheat was not up to the desired level. To improve the quality of his crops he uses chemical fertilizer but the condition of the crop became worse. One of his friends told him to grow a different variety of crops after wheat so as to grow two or three crops in a year with good harvests and use biological manure in place of chemical fertilizers which he prepares by animal excreta and plant waste to get the good quality of crops. He also told him about the good storage of his grains to protect them from the biotic and abiotic losses as in agriculture storage losses are very high.
i. What are the bases on which the next crop is decided to grow in the same field also name the process?
ii. What is the advantage of using biological manure over chemical fertilizers?
iii. Is it possible for the farmer to grow two crops at the same time if yes what is the requirement?
OR
Enlist the biotic and abiotic losses?

Answer

i. The availability moisture and irrigation facilities decide the chose the crop to be cultivated after one harvest and the process knows as crop rotation.
ii. Biological manure help in improving soil structure, enriching the soil with nutrient also reduce the risk of water pollution which is a major problem with chemical fertilizers.
iii. Yes, it is possible to grow two crops simultaneously at the same but the two crops are chosen to grow should have a different nutrient requirement.
OR
Biotic losses caused by - insects, rodents, fungi, mites, and bacteria and abiotic losses are inappropriate moisture and temperature in place of quality.

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Question 34 Marks

Read the following text carefully and answer the questions that follow:
The animal body are covered by epithelial tissue. The epithelial tissue cover most of the organ and cavity with in the body. It also form barrier to keep different body systems separate. The skin, the lining of the mouth, lining of the blood vessels, lung alveoli and kidney tubules are all made of epithelial tissue. The oesophagus and lining of mouth are covered with squamous epithelium. Skin help in protecting the body. The columnar cell have hair-like projection called cilia. Cuboidal epithelium form lining of the kidney tubules and duct of salivary gland.
i. What type of cell are present where absorption and secretion occur?
ii. Skin helps in the protection of body explain?
iii. How cilia clear mucus?
OR
What is glandular epithelium?

Answer

i. Tall epithelial cell.
ii. Skin epithelial cell are arranged in many layer to prevent wear and tear.
iii. Cilia can move and their movement pushes the mucus forward to clear it.
OR
The multicellular gland formed due to the inward folding of a portion of epithelial tissue is called the glandular epithelium.

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Science Case study ( 4 Marks )

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