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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Weeds are unwanted plants in a cultivated field. In this context, consider the following statements:
1. The weeds compete for food, space and light.
2. Weeds are responsible for affecting the growth of the crop.
3. Timely sowing of crops and crop rotation help in weed control.
Which of the statement(s) given above is/are correct?
The ‘scattering of light’ is responsible for which of the following phenomena in nature?
1. Tyndall effect.
2. Colour of water in deep sea.
3. Blue colour of the sky.
4. Rainbow formation.
Select the correct answer using the code given below.
Vectors are living organisms that can transmit infectious pathogens between humans, or from animals to humans. The commonest vectors we all know are mosquitoes. Which among the following vector borne diseases are caused by mosquitoes?
1. Yellow Fever
2. Lymphatic Filariasis
3. Zika Fever
4. Japanese Encephalitis
Select the correct answer using the code given below:
With reference to heterotrophic eukaryotic organisms, Fungi, consider the following statements:
1. All fungus are parasites as they use host organism for food.
2. Lichens have a symbiotic relationship of blue-green algae and fungus.
3. Yeasts and mushrooms are varities of fungus.
Select the correct answer using the code given below:
Read the following statements carefully and select the correct answer from codes given below:
1. Working of electric motors involves the electric effect of electric current.
2. Working of electric generators involves the magnetic effect of moving magnets.
Which of the statement(s) given above is/are correct?
In the Animal Kingdom, which of the following groups of organisms shows the highest level of cellular organisation?
1. Annelids
2. Sponges
3. Coelenterates
Choose the correct answer by using the codes given below:
In context of cells in the human body, consider the following statements:
1. The shape and size of cells are related to the specific function they perform.
2. A cell is able to live and perform all its functions because of its components known as organelles.
3. All cells present in human body have the same organelles.
Select the correct answer using the code given below:
Consider the following statements about the ‘fuel obtained from plastic waste’:
1. It has low octane rating.
2. Lead content is absent in it.
3. It is known as green fuel.
Which of the statements given above is/are correct?
Some countries now use alcohol as an additive in petrol. In context of this, consider the following statements:
1. Addition of alcohol increases the burning efficiency of petrol and reduces knocking.
2. Petrol added with small quantities of alcohol becomes more stable and doesn’t become too hot in warm areas or too cold in freezing temperatures.
3. Alcohol is a cleaner fuel which gives rise to only carbon dioxide and water on burning in sufficient oxygen.
Which of the statements given above is the correct reason for using alcohol as an additive in petrol?
In the question given below, there are two statements marked as Assertion (A) and Reason (R). Read the statements given below carefully:
Assertion (A): The Sun at the sunrise or the sunset appears red whereas at noon, the Sun appears white.
Reason (R): Light from the Sun near the horizon passes through larger distance in the earth’s atmosphere than the light from the Sun overhead.
Choose the correct answer using the codes given below: