Biology · Environmental Studies

Ecosystem Nutrition and Energy Flow

1,093 Questions

Ecosystem nutrition and energy flow questions cover trophic levels, food chains, and biodegradable materials. These concepts frequently appear in general science sections of major competitive exams. Review these questions to build a solid understanding of ecological interactions.

Trophic levels conceptFood chain orderAutotrophic nutritionEnergy assimilationScavengers and decomposers

Ecosystem Nutrition and Energy Flow Questions

Multiple choice botany energy flow in an ecosystem biogeochemical cycle nutrient cycles species, communities and ecosystems

The path through which nutrients are passed from one acceptor to the other is called _______.

  1. Biogeochemical cycle

  2. Biochemical cycle

  3. Chemical cycle

  4. None of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The path through which a nutrient travels as it moves from the air, water or soil into the bodies of living organisms and back to the air, water or soil is called a biogeochemical cycle. It is required to maintain the nutrient level in the ecosystem.

Multiple choice zoology environmental factors soil-nature climate factors abiotic components organisms and environment

Aquatic and terrestrial animals need sulphur and nitrogen to

  1. Grow

  2. Transpire

  3. Evaporate

  4. Photosynthesis
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Sulphur and nitrogen are essential nutrients for the synthesis of proteins and other biological molecules required for growth in all living organisms. Other options like transpiration or photosynthesis are specific physiological processes that do not directly explain the fundamental need for these elements.

Multiple choice vernalisation plant growth growth and development plant growth and development biology

The process of vernalisation is

  1. Aerobic

  2. Anaerobic

  3. Unaffected by aerobic or unaerobic conditions

  4. Dependent upon starvation conditions
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Vernalization is the process by which plant can be induced to flower by exposing it to the prolonged cold or winter. The term was coined by Lysenko in 1928. He stated that certain plants can be made to flower by providing low temperature treatment to young plants or moistened seeds. It is an aerobic process and requires metabolic energy obtained from oxygen.

Thus, the correct answer is 'Aerobic'.

Multiple choice development of plants plant growth growth and development plant growth and development biology

Degrowth takes place when 

  1. Anabolism is higher than catabolism

  2. Catabolism is higher than anabolism

  3. Protoplasmic synthesis is more than apoplasmatic synthesis

  4. Apoplasmatic synthesis is more than protoplasmic synthesis
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
Growth is the net sum of two processes i.e., Anabolism( synthesis) and Catabolism(breakdown).
So, if Anabolism>Catabolism then the tissue will show growth.
If, Catabolism > Anabolism then the tissue will show degrowth.
So, the correct answer is 'Option B- Catabolism is higher than anabolism'.
Multiple choice evs forests and life forest - the dwelling place of animals forest and its importance introduction to forests conservation of forest and wildlife wildlife

Study the following statements regarding food chains and select the correct ones.
(i) Removal of $80\%$ tigers from an area resulted in greatly increased growth of vegetation.
(ii) Removal of most of the carnivores resulted in an increased population of deers.
(iii) The length of food chains is generally limited to $3-4$ trophic levels due to energy loss.
(iv) The length of food chains may vary from $2$ to $8$ trophic levels.

  1. (i) and (ii)

  2. (ii) and (iii)

  3. (i) and (iii)

  4. (iii) and (iv)
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

If carnivores, which feed on deer are removed, then the deer population will flourish. Removal of 80% of tigers from an area will cause an increase in the population of herbivores, which would further feed on more vegetation thus, decreasing its growth. The length of the food chain is limited to 3−4 trophic levels as only 10% of energy is transferred to the next trophic level. Hence after 3−4 trophic levels, there is very little or no energy left to sustain more trophic levels.

So, the correct answer is '(ii) and (iii)'.

Multiple choice evs forests and life forest - the dwelling place of animals forest and its importance introduction to forests conservation of forest and wildlife wildlife

Which of the following provides nutrients to the seedling to grow in forest ?

  1. Grubs

  2. Beetles

  3. Bacteria

  4. Decaying animals dung
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The animals living in the forests excrete the nitrogenous wastes which is acted upon by the microbes. The complex materials in the dung is converted into simpler form of nutrients. These nutrients are taken up by the plants and trees in the forests. The new seedling utilises the nutrients from this decayed dung. 

Thus, the correct answer is option D. 

Multiple choice zoology our environment - our concern biomagnification the effects of human activities on ecosystems bioaccumulation and biomagnification

Which of the following statements is related to biological magnification?

  1. There is a progressive increase in biological activities through trophic levels

  2. There is a progressive increase in the level of harmful substances through trophic levels.

  3. There is a progressive increase in the body weight through trophic levels.

  4. There is a progressive increase in the number of organisms through trophic levels.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The toxic substances which cannot be metabolized get accumulated at a particular trophic level. This leads to increase in the concentration of the toxicant at successive trophic levels. This phenomenon is called as biological magnification and well-known for mercury and DDT. Higher the trophic level of an organism in the food chain greater will be the magnification of toxic chemicals.

So, the correct answer is option B.

Multiple choice zoology our environment - our concern biomagnification the effects of human activities on ecosystems bioaccumulation and biomagnification

Which of the following is the correct order of biomagnification of DDT in an aquatic food chain?

  1. Water- $0.003$ ppm, zooplankton- $0.5$ppm, small fish- $0.04$ppm, large fish -$2$ppm, fish eating birds-$25$ppm
  2. Water-$0.003$ppm, zooplankton-$0.04$ppm, small fish-$0.5$ppm, large fish-$2$ppm, fish eating birds-$25$ppm
  3. Water-$0.003$ppm, small fish-$0.04$ppm. zooplankton-$0.5$ppm, large fish-$2$ppm, fish eating birds-$25$ppm
  4. Water-$0.003$ ppm, fish eating birds-$25$ppm, zooplankton-$0.5$ppm, small fish-$0.04$ppm, large fish-$2.5$ppm
  5. Water-$0.003$ppm, large fish-$0.04$ppm, small fish-$0.5$ppm, zooplankton-$2$ppm, fish eating birds-$25$ ppm
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
DDT is not soluble in water, so it will be least in water (0.003 ppm). It is seen that the level of DDT increases as the food chain progresses. It means, the primary consumers (zooplankton) will have more DDT concentration than the producers, the secondary consumers (small fish) will have more than primary consumers and so on. The highest concentrations will be seen in the top carnivore (fish eating bird). This is because the consumers at the successive trophic level consume more than the previous level to fulfil the energy requirements. Due to this, DDT keeps on accumulating in the successive trophic levels in higher concentrations. This process is called the biomagnification. 
Hence, the correct answer is 'Water-0.003ppm, zooplankton- 0.04ppm, small fish-0.5ppm, large fish-2ppm, fish eating birds-25ppm'
Multiple choice biology biogeochemical cycles carbon cycling mineral coal carbon cycle

If the carbon atoms fixed by producers already have passed through three species, the tropic level of the last species would be.

  1. Scavenger

  2. Tertiary producer

  3. Tertiary consumer

  4. Secondary consumer
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

If the carbon atoms fixed by producer already have passed through three species then the trophic level of the last species(i.e., third species) would be tertiary consumer.
Producers $\rightarrow 1^o$ consumers $\rightarrow 2^o$ consumers $\rightarrow 3^o$ consumers.

Multiple choice biology biogeochemical cycles carbon cycling mineral coal carbon cycle

Which of the owing statements regarding the maintenance of carbon cycle in the biosphere are correct?
a. Plant utilize solar energy to convert $CO _2$ and water into cellular materials and produce oxygen that animals consume.
b. Oxygen produced by the plants during carbon assimilation is not a byproduct.
c. Energy used by an animal comes from the oxidation of plant material releasing $CO _2$ that escapes into the atmosphere.
d. All decaying organic matter on the earth is ultimately degraded by molds and bacteria to yield $CO _2$ that escapes into the atmosphere.
Select the correct answer.

  1. $2, 3$ and $4$
  2. $1, 3$ and $4$
  3. $1$ and $2$
  4. $1, 2, 3$ and $4$
Reveal answer Fill a bubble to check yourself
A Correct answer
Multiple choice botany organisms and their environment energy flow in food chain food chain and energy flow energy flow in ecosystem

What happens in biological magnification?

  1. A progressive increase in the level of energy transferred through trophic levels

  2. A progressive increase in the body weight through trophic levels

  3. A progressive increase in the number of organisms through trophic levels

  4. A progressive increase in the amount of harmful substances through trophic levels
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Biomagnification (or bioaccumulation) refers to the ability of living organisms to accumulate certain chemicals to a concentration larger than that occurring in their inorganic, non-living environment, or in the case of animals, in the food that they eat.  The contaminants include heavy metals namely mercury, arsenic, pesticides such as DDT, and polychlorinated biphenyls (PCBs) compounds which are then taken up by organisms because of the food they consume or the intoxication of their environment. These materials are highly present in a variety of household and industrial chemicals. The harmful substances then build up inside the organism’s cells. When organisms in the higher food chain consume the organisms containing the toxins below their trophic levels, the toxins gradually become concentrated in the higher food chain. Because this is a repetitive process in the ecosystem and throughout the entire food chain, the higher organisms are the ones that will accumulate most of the toxins.

So the correct option is 'a progressive increase in the level of energy transferred through trophic levels'.

Multiple choice botany organisms and their environment energy flow in food chain food chain and energy flow energy flow in ecosystem

As energy is passed from one trophic level to another, the amount of usable energy

  1. increases

  2. decreases

  3. remains the same

  4. energy is not passed from one trophical level to another
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
The transfer of energy from one trophic level to next trophic level follows 10 percent law known as Lindeman's law of trophic efficiency which states that the efficiency of energy transferred from one trophic level to the next higher trophic level is about 10%. Rest of the energy is lost in respiration. So the energy decreases as it is transferred to subsequent trophic levels.
So, the correct answer is 'decreases'.
Multiple choice botany ecosystem : structure and function energy flow in food chain food chain and energy flow energy flow in ecosystem

The pyramid of energy is always upright for any ecosystem. This situation indicates the fact that?

  1. Producers have the lowest energy conversion efficiency

  2. Carnivores have a better energy conversion efficiency than herbivores

  3. Energy conversion efficiency is the same in all trophic levels

  4. Herbivores have a better energy conversion efficiency than carnivores
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The pyramid of energy is always upright because energy is lost as heat at each transfer, and producers have the highest energy availability, which decreases as you move up the trophic levels.