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Based on the table given below, identify the type of natural selection taking place.
| Size of the seeds | % of germination |
| Small | 75% |
| Medium | 15% |
| Large | 75% |
Concept: Ecosystem Services
Given below are the features of Seed A and Seed B. Study them carefully and answer the question that follows.
| SEED A | Papery endosperm, swollen cotyledon, perisperm develops from nucellus, suspensor, haustoria substitute endosperm. |
| SEED B | Swollen endosperm, papery cotyledons or absent, perisperm does not develop from nucellus, suspensor and haustoria do not substitute endosperm. |
Identify the type of Seed A and Seed B. Cite one example of each of Seed A and Seed B.
Concept: Ecosystem Services
| In a forest ecosystem, a large population of insect feeds upon a banyan tree. Several small birds feed upon these insects. The small birds are fed upon by big-sized birds. |
- With respect to this ecosystem, draw a pyramid for each biomass and a pyramid of number.
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If 20,000 Kcal energy is available at the level of insects, calculate the amount of energy available at the level of big-sized birds.
Concept: Ecological Pyramids
Give one significant contribution of the given scientist
E. Wilson
Concept: Biodiversity
Define Ramsar Sites.
Concept: Biodiversity
Define Biodiversity.
Concept: Biodiversity
Define Eutrophication.
Concept: Biodiversity
Explain the chemiosmotic hypothesis for ATP synthesis.
Concept: Biodiversity
Study the graph given below and answer the following questions:

- Explain the ecological principle represented by the graph and write a mathematical expression for the same.
- What will happen if the slope of the line ‘b’ becomes steeper?
Concept: Importance of Biodiversity
The table given below shows the Area, Y-intercept and regression coefficient of the continents namely, Africa and Europe. Study the table carefully and answer the questions that follow:
| Africa | Europe | |
| Area (A) | 62,000 km sq. | 65,000 km sq. |
| Y-intercept | (C) 10 | 20 |
| Regression coefficient (Z) |
1 | 1 |
- Calculate the species richness (S) of each continent.
- Which of these continents shows a higher biodiversity?
- State any two factors that cause an increase in biodiversity.
Concept: Biodiversity
Name any two factors responsible for the loss of biodiversity in a geographical region.
Concept: Loss of Biodiversity
Samson and Dorothy surveyed two islands, ‘A’ and ‘B’. They recorded the relevant data in the following format in their research folder:
| Parameter | Island A | Island B | |
| (a) | Area (A) | 45 × 103 Km2 | 12 × 105 Km2 |
| (b) | Regression co-efficient (Z) | 1 | 1 |
| (c) | Y-intercept | 20 | 10 |
- Derive the species-richness for each island.
- Which island exhibits greater biodiversity? Support your answer with a reason.
Concept: Biodiversity
What do you mean by Biochemical Oxygen Demand (BOD)?
Concept: Environmental Issues >> Water Pollution
State any four measures to control noise pollution.
Concept: Environmental Issues >> Noise Pollution
Discuss the various In-situ and Ex-situ strategies for conservation of biodiversity.
Concept: Deforestation and Its Causes
The level of air pollution is very high in a city. Suggest any four measures which should be taken by the government to control it.
Concept: Prevention and Control of Air Pollution
|
The scientists from a research institute collected samples of water from sewage pipes of two different cities, A and B. On analysis, the BOD value of the sample from city A was found to be 500 mg/L. The BOD value of the sample from city B was 200 mg/L. |
- Which one of the two cities needs a sewage treatment plant?
- Briefly discuss the steps involved in the treatment of sewage.
- What will be the effect of sewage treatment on the value of BOD?
Concept: Eutrophication
