Advertisements
Advertisements
प्रश्न
Will the levels of biological magnification be different at different levels of the ecosystem?
Advertisements
उत्तर १
उत्तर २
The level of these harmful substances will go on increasing from one trophic level to the next. When certain harmful substances enter the food chain at the level of primary producers, they get concentrated many times at each subsequent trophic level.
APPEARS IN
संबंधित प्रश्न
Give reason to justify the following: The existence of decomposers is essential in a biosphere.
Give reason to justify the following: Flow of energy in a food chain is unidirectional.
"Our food grains such as wheat and rice, the vegetables and fruits and even meat are found to contain varying amounts of pesticide residues." State the reason to explain how and why it happens?
Which category of organisms forms the starting point of a food chain?
Name one decomposer.
Can the organisms of any trophic level be removed without causing any damage to the ecosystem? Will the impact of removing all the organisms in a trophic level be different for different trophic levels?
At which trophic level a person is feeding when he is eating bread.
Write one or two word for the following statement/definition :
Organisms which depend on the producers for food either directly or indirectly
What is a food chain?
Which of the following represents a possible food chain found in a pond :
| Primary producers |
Primary consumers | Secondary consumers |
| (a) green algae | fish | mosquito larvae |
| (b) fish | green algae | mosquito larvae |
| (c) mosquito larvae | fish | green algae |
| (d) green algae | mosquito larvae | fish |
A food chain occurring in the sea which provides food for many people can be written as :
phytoplankton → zooplankton → X → Y
What could be X?
What would happen to the number of rabbits and grass plants if the number of foxes decreased?
Fill in the following blank with suitable word :
Pesticides enter the food chain at the ...........level
Explain why, the flow of energy in the ecosystem is said to be unidirectional.
Calculate the amount of energy that will be available to big fish in the following food chain, if 10,000 J of energy is available to small algae from the sun :
Small algae → Zooplankton → Fish → Big fish
Your mother always thought that fruit juices are very healthy for everyone. One day she read in the newspaper that some brands of fruit juices in the market have been found to contain certain level of pesticides in them. She got worried as pesticides are injurious to our health.
(a) How would you explain to your mother about fruit juices getting contaminated with pesticides?
(b) It is said that when these harmful pesticides enter our body as well as in the bodies of other organisms they get accumulated and beyond a limit cause harm and damage to our organs. Name the phenomenon and write about it.
Bacteria and fungi are called decomposers.
Which group of organisms are not constituents of a food chain?
- Grass, lion, rabbit, wolf
- Plankton, man, fish, grasshopper
- Wolf, grass, snake, tiger
- Frog, snake, eagle, grass, grasshopper
DDT was sprayed in a lake to regulate breeding of mosquitoes. How would it affect the trophic levels in the following food chain associated with a lake? Justify your answer.
Study the picture given below showing three food chains (a), (b) and (c) and answer the following questions:
- Name the type of ecosystems that exist in food chains (b) and (c).
- The first trophic level in all food chains is producers. Why? What percentage of solar energy do these producers capture for their use?
- Why are the arrows shown in the diagram in one direction only and not vice versa? Justify.
