Consider the following statements about ‘Biochemical Oxygen Demand’ (BOD):
1. It is the amount of oxygen required by bacteria to break down the organic matter present in a certain volume of a sample of water.
2. Highly polluted water have BOD value of less than 5 ppm.
Which of the statements given above is/are correct?
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Compass is an important tool used for navigation since old days. In this context, consider the following statements:
1. The compass needle is a magnet which align itself in a particular direction.
2. The compass needle always points towards the magnetic south pole of the earth.
Which of the statement(s) given above is/are correct?
Match the following pairs with reference to common air pollutants and its effect/impact on plants and animals:
Pollutant | Associated Effect |
1. Sulphur dioxide | A. Aging in plants. |
2. Oxides of nitrogen | B. Reduces oxygen carrying capacity of blood. |
3. Hydrocarbons | C. Red haze in the traffic. |
4. Carbon monoxide | D. Stiffness of flower buds. |
Select the correct answer using the code given below.
Read the following statements carefully in the context of ‘particulate pollutants’?
1. Smoke particulates consist of gaseous or mixture of gaseous and liquid particles formed during combustion of organic matter.
2. Dust is composed of fine solid particles produced during crushing, grinding and attribution of solid materials.
3. Mists are produced by particles of spray liquids and by condensation of vapours in air.
4. Fumes are generally obtained by the condensation of vapours during sublimation, and boiling.
Which of the statements given above are correct?
Which of the following statement(s) is/are correct?
1. The B-lymphocytes in human body produce an army of proteins in response to pathogens into our blood to fight with them.
2. The T-lymphocytes mediate cell-mediated immunity (CMI) which is responsible for the graft (transplanted body-part) rejection.
Select the correct answer using the code given below.
Unicellular organism are unique because they are made up of a single cell only. Which of the following is/are examples of unicellular organisms?
1. Amoeba
2. Yeast
3. Bacteria
Select the correct answer using the code given below:
In the context of ‘immunity’ in human body, which of the following statements is/are correct?
1. Skin on our body is an example of innate immunity.
2. Acquired immunity is characterised by memory.
3. Injecting the microbes deliberately during immunisation induce passive immunity.
Select the correct answer using the code given below.
Consider the following statements with reference to the ‘magnetic field’ of a bar magnet:
1. Magnetic field is a quantity that has both direction and magnitude.
2. Inside the magnet, the direction of field lines is from its south pole to north pole.
3. Magnetic field-lines of two different magnets can intersect each other.
Which of the statement(s) given above is/are correct?
Consider the following statements:
1. The motion of the moon around the earth is due to the centrifugal force.
2. The moon rotates around its axis due to the gravitational pull of the earth.
Which of the statement(s) given above is/are NOT correct?
Consider the following statements about ‘Acid Rain’:
1. Oxides of sulphur and nitrogen are major contributors to acid rain.
2. Acid rain is good for agriculture as it provides nitrogen for the growth of plants.
3. When acid rain flows into the river, it increases the pH level of river water.
Which of the statements given above is/are correct?
Read the following statements carefully:
1. Motion of the moon around the earth.
2. Tides in open seas.
3. Rotation of earth.
4. Motion of planets around the Sun.
Which of the events given above are result of force of ‘Gravitation’?