Which of the following is not a biotic component of an ecosystem ?
Rainfall is not a living organism
If a grasshopper is eaten by a frog, then the energy transfer will be from
Which of the following is not biodegradable ?
Plastic bags are synthetic materials. These are not degraded by bacteria.
Which group of organisms are not constituents of a food chain?
(i) Grass, lion, rabbit, wolf
(ii) Plankton, man, fish, grasshopper
(iii) Wolf, grass, snake, tiger
(iv) Frog, snake, eagle, grass, grasshopper
The organisms in an ecosystem are related through food requirements. This relationship is called food chain. In option (i) grass is eaten by rabbit, rabbit is consumed by wolf and lion eats wolf. In option (iv) grasshopper eats grass, frog eats grasshopper, snake eats frog and eagle consumes snake. In option (ii) grasshopper is found in terrestrial ecosystems not aquatic ecosystems. In option (iii) there is no herbivore animal to consume grass. Thus, the correct answer is option C.
The average value for the amount of organic matter that is present at each step and reaches the next level of consumers is
As per standard 10% rule.
Excessive exposure of humans to UV-rays results in
(i) damage to immune system
(ii) damage to lungs
(iii) skin cancer
(iv) peptic ulcer
UV rays or ultraviolet rays can affect human health in many ways like causing skin cancer or weakening immune system. Excessive exposure to UV rays can lead to skin cancer because the UV rays cause damage to the DNA in skin cells.
As human beings occupy the top level in any food chain, the maximum concentration of insecticides get accumulated in our bodies. This phenomenon is known as
Concentration of chemicals like insecticides in living system is called biological magnification.
In the garden ecosystem, which of the following are producers?
An ecosystem includes
An ecosystem includes both living and non-living organisms.
Which of the following is an autotroph?
Which one of the following is an artificial ecosystem ?
Crop field is an artificial ecosystem.
In a food chain, the third trophic level is always occupied by
The third trophic level in a food chain is always occupied by carnivores.
Which of the following is a logical sequence of food chain
In a given food chain, suppose the amount of energy at fourth trophic level is 5 kJ, what will be the energy available at the producer level ?
Grass → Grasshopper → Frog → Snake → Hawk
According to 10% rule, energy available at producer level will be 5 x 10 x 10 x 10 = 5000 kJ.
Which of the following statements about food chain and energy flow through ecosystem is false?
There are many food chains which are interconnected to form the food web and so one organism can feed at different trophic levels in the different food chain. There is a 0gradual decrease in the energy of the increasing trophic levels due to the loss of energy with each transfer. The producers are the organisms which can synthesize food and the organisms which feed on the other sources are known as consumers. The detrivores are the organisms which feed on the dead matter of the organisms which belong to all the trophic levels.
Organisms of a higher trophic level which feed on several types of organisms belonging to a lower trophic level constitute the
Organisms of a higher trophic level which feed on several types of organisms belonging to a lower trophic level constitute the food web.
First link in any food chain is usually green plants because
Depletion of ozone is mainly due to
Depletion of ozone layer is mainly due to chlorofluorocarbon compounds.
A food chain comprising birds, green plants, fish and man. The concentration of harmful chemical entering the food chain will be maximum in
Every food chain in the ecosystem begins with………. which are the original source of food.
All green plants and few blue-green algae which can produce food by photosynthesis are called the producers.