Chapter 5
Our Environment: Energy Flow in the Ecosystem Solution
1) Choose the right option.
(i) There are about 2234 insects, 56 birds and 3 snakes on a mango tree. The pyramid ofenergy would be-
(a) Straight (b) Inverted (c) rectangular (d) uncertain.
Ans: – (b) Inverted.
(ii) Fungi started growing on a moist piece of bread left in the open. After sometime someinsects like houseflies etc. were seen there. The organisms at the last trophic levelwould be-
a) Food (b) bread (c) house fly (d) none.
Ans: – (b) bread.
(iii) There are 3 stages in the life cycle of an insect – egg, larva, pupa, adult. If the stages ofegg, larva and pupa are completed in the body of a particular organism then theinsect’s life cycle is completed in how many ecosystems?
a) 1 (b) 2 (c) 3 (d) 4.
Ans: –(d) 4.
(iv) What will happen if all insect eating birds were removed from a particular cropland area?
(a) Crop production will increase.
(b) Insect infestation will increase
(c) Increase in the number of other birds
(d) No effect.
Ans: – (b) insect infestation will increase.
(v) Cow feeds on grass. Its dung is used to make dung cakes which are used as fuel. The burning of the dung cakes produce smoke that reaches the atmosphere and the ashesare mixed with soil. This adds nutrients for grass to grow. This process is an example of-
(a) Food chain (b) Food web (c) Nutrient cycle (d) Life cycle.
Ans: – (c)Nutrient’s cycle.
(vi) The food chain in a pond starts from some water plants that are eaten by certain fishesthose eaten by others extending finally to humans. The energy here from one trophiclevel to another will-
(a) Gradually decrease (b) gradually increase
(c) will be same (d) will be less sometime and more sometime.
Ans: – (a) Gradually decrease.
(vii) The number of organisms in a garden was estimated as 5567 grasses, 453 shrubs, 23trees and 7769 animals. The primary productivity of this area will be nearly equal to-
(a) Biomass of all organisms of the garden
(b) Biomass of all the plants of the garden
(c) Biomass of the animals of the garden
(d) Biomass of only 5567 grasses.
Ans: – (a) Biomasses of all organisms of the garden.
2) A type of fungi is grown on rice husk. We eat the fungi. Does it show a food chain? Illustrate the food chain. What is the source of energy for this food chain?
Ans: – There are various types of fungi that are help in our daily food processing by different way. For example, for making pizza mushroom also needed sometimes. The fungi decompose the food. Rhizobium is a fungus help in the food chain. Sometimes this fungus returns organic material to the ground which help the crop production.
3) How does energy flow in any ecosystem? Explain in your own words.
Ans: – Energy always flows from one organism to other organisms. As energy transform only one direction it doesn’t flow reverse. From the decompose organisms the plant takes nutrients and it then passes to the animal or the human being. The humans being get energy by this way so energy always circular process.
4) What will happen if only plants and humans are left on earth as living organisms or biotic component?
Ans: – The energy cycle will hamper by this situation. If there are no such decompose bacteria like organisms then the nutrients of the plants would not be formed so the energy would not be formed in the primary section and doesn’t it transform too other. The nutrients cycle would hamper.
5) What will happen if the natural flow of energy in an ecosystem is disrupted? Explain with an example.
Ans: – The natural flow of energy if disrupted then the energy chain would be affected. There will be a shortage of nutrients or sometimes if it goes beyond the control some community would be vanished. If any organisms or the sun, main energy source if absent by any chance the ecosystem would be hampered.
6) How does the availability of energy affect the number of organisms at different trophic levels?
Ans: – The availability of the primary substance always be more than the secondary substance for maintain the balance in the ecosystem. As for example we see that there is huge source of herbivores than the carnivorous. To maintain balance the no of substance is decreasing from primary to tertiary.
7) Site an example where you find the effect of human beings on an ecosystem. Explain why you think so and suggest some means to minimize the same.
Ans: – Day by day the pollution of our environment is increasing. This change leads to the liberated the various toxic gas in the air which cause the different effect on the soil as well as the plant also. The ecosystem will be hampered by these changes which disrupted the energy flow from the primary to the secondary.