Question: From NCERT NEET Derived PYQ AIIMS - 2017
Which one option is incorrectly matched regarding biological magnification of DDT in aquatic ecosystem.
(1) Small fish 0.5 ppm
(2) Large fish 2 ppm
(3) Fish eating birds 25ppm
(4) Zoopkankton 0.003 ppm
Answer ▽
(4) Zoopkankton 0.003 ppm
DDT stands for dichlorodiphenyldichloroethane and is an insecticide. Insecticides are non-degradable substances; hence tend to move into the organisms. Their concentration increases in each successive tropical level. The concentration of DDT starts at 0.003 ppb (parts per billion) in the water. When it moves up in each tropical level, its concentration increases through biological magnification and reaches up to 25 ppm (parts per million) in fish-eating birds.
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Question: From NCERT NEET Derived PYQ
The range of biomagnification of DDT in an aquatic food chain, if starting from 0.003 ppb level in water may go at fish-eating bird level upto:
a. 0.3 ppm
b. 3.0 ppm
c. 25.0 ppm
d. 0.003 ppm
Answer ▽
When the toxic substances enter into the aquatic food chain, they get accumulated in the body of the organisms and cannot be excreted out, and in this way pass from one trophic level to the next trophic level. The concentration becomes highest at the maximum level. When the toxic substances get deposited into the organisms of higher trophic levels, it is called bio-accumulation.
DDT stands for dichlorodiphenyldichloroethane and is an insecticide. Insecticides are non-degradable substances; hence tend to move into the organisms. Their concentration increases in each successive tropical level. The concentration of DDT starts at 0.003 ppb (parts per billion) in the water. When it moves up in each tropical level, its concentration increases through biological magnification and reaches up to 25 ppm (parts per million) in fish-eating birds.
Hence, the correct answer is option (C).
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Question: From NCERT NEET Derived PYQ AIIMS - 2016
One greenhouse gas contributes 14% to total global warming and another contributes 6%. These are respectively identified as
(1) N2O and CO2
(2) CFCs and N2O
(3) methane and CO2
(4) methane and CFCs
Answer ▽
(2) CFCs and N2O
The green house gases are Chlorofluorocarbons (CFC's), Carbon dioxide (CO2), Methane (CH4) and Nitrous Oxide (N2O).
CFCs - 14%
CO2 - 60%
CH4 - 20%
N2O - 6%
So, the correct answer is 'CFC and N2O'.
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Question: From NCERT NEET Derived PYQ AIIMS - 2015
Match the following and select the correct option.
| Column- I | Column- II |
| A. Emphysema B. ADA deficiency C. Eutrophication D. Biomagnification | (i) Increase in the concentration of non-biodegrable substances in food chains (ii) -1 antitrypsin (iii) Bone marrow transplantation (iv) Nutrient enrichment of water body |
(1) A - (iii), B - (ii), C - (iv), D - (i)
(2) A - (ii), B - (iii), C - (iv), D - (i)
(3) A - (i), B - (iii), C - (ii), D - (iv)
(4) A - (iv), B - (ii), C - (iii), D - (i)
Answer ▽
(2) A - (ii), B - (iii), C - (iv), D - (i)
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Question: From NCERT NEET Derived PYQ AIIMS - 2013
A large quantity of urban sewage is drained to nearby village river. Which among the given conditions would happen after mixing of sewage into the river?
(i) Biochemical oxygen demand (BOD) of receiving water body increases.
(ii) Dissolved oxygen of receiving water body decreases.
(iii) It will not cause mortality among fishes and other aquatic creatures
(iv) It will lead to nutrient enrichment of receiving water body.
(1) (i), (ii) and (iii)
(2) (i), (ii) and (iv)
(3) (ii) and (iii)
(4) (iii) and (iv)
Answer ▽
(2) (i), (ii) and (iv)
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Question: From NCERT NEET Derived PYQ AIIMS - 2011
In vehicles, catalytic converters are used
(1) to increase mileage of vehicles
(2) to convert CO2 into carbonates
(3) to increase the efficiency of lead mixed petrol
(4) to convert CO to CO2.
Answer ▽
(4) to convert CO to CO2
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Question: From NCERT NEET Derived PYQ AIIMS - 2011
Which of the following statements is correct ?
(1) Catalytic converter can separate particulate matter of diameter less than 2.5 micrometers.
(2) Histones are acidic in nature that forms core for DNA packaging
(3) Lactobacillus is not present in dough used in idli formation.
(4) Template with polarity 5' 3' has continuous DNA replication.
Answer ▽
(1) Catalytic converter can separate particulate matter of diameter less than 2.5 micrometers.
The catalytic converts help in reducing atmospheric pollution by converting harmful unburnt hydrocarbons into less toxic forms. It converts carbon monoxide into carbon dioxide, nitric oxide to nitrogen gas, and hydrocarbons to carbon dioxide and water.
-Histone proteins are basic proteins that are positively charged in nature. DNA also contains less positively charged proteins called non-histone proteins. Histone proteins are rich in amino acids such as lysine and arginine. These amino acids have positively charged components in their side chains and are responsible for the positive charge of histone proteins.
-Lactobacillus is a gram-positive bacteria that produces lactic acid. It is present in the normal flora of bacteria seen in our gut. Lactobacillus is actually good for our health. It helps us by preventing the growth of certain microbes that are harmful to our health. It also helps in the absorption of some vitamins from the gut.
-DNA replication is the process by which new DNA is synthesized from pre-existing DNA. During replication, DNA is unwound up to a point and it appears to be a Y-shaped structure called the replication fork. Two types of strands are formed during replication. They are leading strand and lagging strand. In the leading strand, DNA replication is continuous and the template has 3’-5’ polarity. On the other hand, in lagging strands, several small fragments are made that are later joined by enzyme DNA ligase.
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Question: From NCERT NEET Derived PYQ AIIMS - 2009
The government of India in 1980s has introduced a concept to work closely with the local communities for protecting and managing forests. The concept is
(1) Forest Research Institutes
(2) Panel of focal communities for forest management
(3) Joint forest Management
(4) Jhum Cultivation
Answer ▽
(3) Joint forest Management
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Question: From NCERT NEET Derived PYQ AIIMS
The thickness of the ozone is measured in terms of:-
(1) P
(2) DU
(3) µ
(4) RA
Answer ▽
(2) DU
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Question: From NCERT NEET Derived PYQ AIIMS
The Montreal Protocol refers to
(1) persistent organic pollutants
(2) global warming and climate change
(3) substances that deplete the ozone layer
(4) biosafety of genetically modified organisms.
Answer ▽
(3) substances that deplete the ozone layer
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Question: From NCERT NEET Derived PYQ AIIMS
Biological Oxygen Demand (BOD) is a measure of
1. industrial wastes poured into water bodies
2. extent to which water is polluted with organic compounds
3. amount of carbon monoxide inseparably
4. amount of oxygen needed by green plants during night.
Answer ▽
2. extent to which water is polluted with organic compounds
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