Solution: When two different dice are thrown, the total number of outcomes = 36. Let E1 be the event of getting the sum of the numbers on the two dice is 10. These numbers are (4 ,6), (5,5)...
Why is damage to the ozone layer a cause for concern? What steps are being taken to limit this damage?
The ozone layer is a protective layer in the earth's atmosphere. It prevents harmful UV rays from entering the world as these rays are dangerous and can lead to skin cancer. But air pollution such...
If all the waste we generate is biodegradable, will this have no impact on the environment?
The bio degradable waste decomposes with the help of microorganisms into simple materials that can be used by manufacturers as raw materials. But the following are the consequences on the...
What are the problems caused by the non-biodegradable wastes that we generate?
Problems caused by non-biodegradable wastes: 1. Cannot be decomposed by micro-organisms. 2. As the number increases, dumping becomes a problem. 3. Indestructible waste such as heavy metals can enter...
What is biological magnification? Will the levels of this magnification be different at different levels of the ecosystem?
The biological magnification can be described as a continuous increase in the concentration of non-biodegradable waste in the food chain. As there is an increase in the initial level of the...
Will the impact of removing all the organisms in the trophic level be different for different trophic levels? Can the organisms of any trophic level be removed without causing any damage to the ecosystem?
Yes, the effect of removing all living things at the trophic level will vary from different trophic levels. For example, if all producers are removed, there is a chance of death or migration of top...
What will happen if we kill all the organisms in one trophic level?
If we kill all creatures in one trophic level, the supply of food to the next level will slow down leading to environmental inequality. As a result the animals at higher levels will die which makes...
Which of the following are environment-friendly practices?
a. Carrying cloth bags to put purchases in while shopping
b. Switching off unnecessary lights and fans
c. Walking to school instead of getting your mother to drop you on her scooter
d. All of the above
Answer: d) All of the above Explanation: Using cloth bags instead of plastic bags, turning off the unused lights and fans, walking for a short distance travel instead of using vehicles are all a...
Which of the following constitute a food-chain?
a. Grass, wheat and mango
b. Grass, goat and human
c. Goat, cow and elephant
d. Grass, fish and goat
In the option, (b) Grass, goat and human Grass acts as the producer Goat acts as the primary consumer Man acts as the secondary consumer Hence, option (b) constitutes a food chain.
Which of the following groups contain only biodegradable items?
a. Grass, flowers and leather
b. Grass, wood and plastic
c. Fruit peels, cake and lime juice
d. Cake, wood and grass
The groups (a), (c) and (d) contains only biodegradable items. (a) Grass, flowers and leather (c) Fruit peels, cake and lime juice (d) Cake, wood and grass The group (b) has plastic in it which is a...
How can you help in reducing the problem of waste disposal? Give any two methods.
Methods to reduce the problem of waste disposal: 3 R's: Following 3 R’s can reduce the problem of garbage disposal. 3 R’s stands for reduce, recycle and reuse. Reducing the use of their vehicles and...
What is ozone and how does it affect the ecosystem?
Ozone is a molecule made up of three oxygen atoms and is known as oxygen isotope. The primary function of the ozone layer is to provide extra protection from the sun's harmful rays to the earth....
Give any two ways in which non-biodegradable substances would affect the environment.
The ways in which non-biodegradable substances would affect the environment: 1. They cause air, soil, and water pollution. 2. It can cause bio magnification in the food chain that has led to human...
Give any two ways in which biodegradable substance would affect the environment.
The ways in which biodegradable substances would affect the environment: 1. They keep the environment clean as it decomposes easily. 2. They can easily pass the geochemical cycle with the help of...
Why are some substances biodegradable and some non-biodegradable?
The reason why some substances are biodegradable and some are non-biodegradable is because microorganisms such as bacteria and decomposers as saprophytes have a specific role to play. They can only...
What is the role of decomposers in the ecosystem?
Role of a decomposer in the ecosystem: 1. Acts as an environmental cleaner by decomposing dead plants and animals 2. Helps to regenerate nutrients 3. Provides space for new creatures in the...
What are the trophic levels? Give an example of a food chain and state the different trophic levels in it.
Food or energy transfer occurs at various levels and these levels in the food chain and this is known as trophic levels. Example: Food chain - Grass → Goat → Human 1. Grass - first trophic level 2....
Why is it necessary to remove sulphur from petroleum products?
a. To reduce the emission of sulphur dioxide in exhaust fumes b. To increase the efficiency of automobiles engines c. To use sulphur removed from petroleum for commercial purposes d. To increase the...
The relation between species richness and area for a wide variety of taxa turns out to be a rectangular hyperbola. Give a brief explanation
German naturalist and geologist Alexandar von Humboldt noted that within the region a large number of extinct species with continuous growth are possible, but only reaching a limit. In the...
Explain briefly the ‘rivet popper hypothesis’ of Paul Ehrlich.
The Rivet popper hypothesis is a description of the threat to animals and plants. Paul Ehrlich thought that the aircraft was called an ecosystem and parts of aero aircraft referred to local species....
Though the conflict between humans and wildlife started with the evolution of man, the intensity of the conflict has increased due to the activities of modern man. Justify your answer with suitable examples.
The conflict between humans and wildlife began with the existence of man, and the intensity of the conflict has grown as a result of modern human activities. This is a true statement. Over the...
Can you think of a scientific explanation, besides analogy used by Paul Ehrlich, for the direct relationship between diversity and stability of an ecosystem?
Paul Ehrlich has taken nature as an airplane composed of thousands of cracks showing different species. If every passenger starts to get off the rivet, the plane will not be safe, moreover the...
How can you, as an individual, prevent the loss of biodiversity?
Biodiversity can be saved by enforcing strict conservation strategies and policies with regard to natural resource management. We, the people, must always be aware of the diversity and importance of...
Elaborate how invasion by an alien species reduces the species diversity of an area.
Decreases or extinctions may occur when other species are included with native species. Present species change the entire habitat because many native species only grow in particular. Some attackers,...
What is co-extinction? Explain with a suitable example?
With the extinction of a species, the species of plants and animals that accompany it in this way also cease to exist and this process is known as co-extinction. For example, plant and pollinator...
Species diversity decreases as we move away from the equator towards the poles. What could be the possible reasons?
The diversity of species decreases as we move from the equator to the poles because the sunlight is less visible due to the oblique sunlight but the equator having more direct sunlight rays. Cold...
Describe the consumptive use value of biodiversity as food, drugs and medicines, fuel and fibre with suitable examples.
Biodiversity offers a wide range of goods from agricultural crops to trees and events where exact value and cost can be provided. 1. Food: A large number of wild plants are eaten by humans as 90% of...
What is an ecosystem service? List any four important ecosystem services provided by natural ecosystems. Are you in favor or against levying a charge on the service provided by the ecosystem?
The services provided by the ecosystem are called ecosystem services. Four important environmental services are, 1. Air and water purification 2. Provides shelter and food for wildlife. 3....
Is it true that there is more solar energy available in the tropics? Explain briefly.
Yes, tropical areas really do have a lot of solar energy because sunlight is directed toward the equator and on the other hand, the sunlight in the highlands comes with a more slanted radiation.
Suggest a place where one can go to study coral reefs, mangrove vegetation and estuaries.
The coral reefs are found in marine areas, mangrove vegetation and rivers also found in coastal areas and are located near the sea. I therefore suggest Australia to learn about coral reefs,...
What are sacred groves and their role in biodiversity conservation?
The sacred groves are found on the hills of Kasi and Jaintia in Meghalaya, on the hills of Aravalli in Rajasthan, the Western Ghats in the Karnataka region and in Maharashtra and Sarguja among many...
What is an endangered species? Give an example of an endangered plant and animal species each?
An endangered species is a classified species that is likely to become extinct soon. Examples: 1. An estimated 40,000 Asian elephants are left. 2. The average Bengal Tiger 2,500 remaining. 3....
List any two major causes other than anthropogenic causes of the loss of biodiversity.
The two main causes are Habitat Loss and Fragmentation which is an important cause of extinction of plants and animals and overuse of natural resources by humans.
Humans benefit from the diversity of life. Give two examples.
Humans are heterotrophs that rely on natural sources. The Amazon rainforest provides about 40% of oxygen for humans and some sources are diatoms. Foods such as grains, lumps, fruits all of which are...
How do scientists extrapolate the total number of species on Earth?
The scientists prepare a clear statistical representation of the tropical regions as well as calculate gross estimation of a number of the biomass of the species.
What could be the possible explanation for the greater vulnerability of amphibians to extinction as compared to other animal groups?
Reasons of the extinction of amphibian: 1. Climate change 2. Chytridiomycosis
What criteria should one use in categorizing a species as threatened?
1. The speed of the decline in the population. 2. Certain Geographical regions. 3. The size of the population is observed.
Why are the conventional methods not suitable for the assessment of biodiversity of bacteria?
It is very difficult to distinguish bacteria with our eyes. There are germs that cannot be cultured in normal media which makes it difficult to study their biochemistry. Culture media can be easily...
There is greater biodiversity in tropical /subtropical regions than in the temperate region. Explain.
The great diversity of life is found in tropical and subtropical areas because of its close proximity to the equator.
Is it possible that productivity and diversity of a natural community remain constant over some time, say one hundred years?
No. It is impossible to always preserve the product and the natural community for more than a hundred years. This is because over time the population size increases which leads to the depletion of...
A species-area curve is drawn by plotting the number of species against the area. How is it that when a very large area is considered the slope is steeper than that for smaller areas?
According to Alexander Von Humboldt, as the richness of the species gradually grows when explosions will also increase. This is due to the availability of natural resources which is also...
Discuss one example, based on your day-to-day observations, showing how the loss of one species may lead to the extinction of another.
Example of the loss of one species leading to the extinction of another is the relationship of plant and pollinator. In this case, if one of them disappears leading to the final extinction of the...
Of the four major causes for the loss of biodiversity (Alien species invasion, habitat loss and fragmentation, over-exploitation and co-extinctions which according to you is the major cause for the loss of biodiversity? Give reasons in support.
Reasons for the loss of biodiversity: The loss of habitat and fragmentation is a major cause of this problem because this results in depletion of natural resources leading to food shortages for...
How is the presently occurring species extinction different from the earlier mass extinctions?
The mass extinction which occurred earlier was due to the natural calamities such as flood, volcanic eruption and so on. The recently occurring extinction is a lot faster when compared to the...
What is common to the species shown in figures A and B?
Similarity between the two species in the above figure is that both the species are vertebrates’ The Tiger is from mammalian phylum whereas the snake is from reptilian phylum.
What is common to the species shown in figures A and B?
Similarity between the two species in the above figure is that both the species are angiosperms.
Define the terms (i) Bioprospecting (ii) Endemism
(i) Bioprospecting: The process of discovering plant and animal species in which medicines and other commercial valuables are available is called the bioprospecting. (ii) Endemism: An ecosystem of...
What is the expanded form of IUCN?
The IUCN is an international organization found in France and the expansion of IUCN is, I - International U - Union of C - Conservation of N – Nature
What does the term ‘Frugivorous’ mean?
The term Frugivorous means the birds and animals that eat fruits and is found in the tropical forests.
Define gene pool.
The gene pool is the group of genes in a population of interbreeding organisms that involve each gene at a particular frequency in relative to its alleles.
What is Red Data Book?
The Red Book Data includes records of all endangered species and about 784 species recorded there are 338 vertebrates, 359 invertebrates and 87 are plants.
Why is genetic variation important in the plant Rauwolfia vomitoria?
The plant Rauwolfia vomitoria produces a variety of chemicals that have medicinal properties, the most important of which is the reserpine used to treat mental illness. This alkaloid is extracted...
How does species diversity differ from ecological diversity?
Species diversityEcological diversityThe diversity at the level of species and is resistant to rare disturbances is known as species diversity.The diversity at the level of ecosystem and the changes...
What is the difference between endemic and exotic species?
Endemic speciesExotic speciesEndemic species are local or indigenous species found in a particular geographical area,Exotic species are localized and are derived from one geographical region to...
Explain as to how protection of biodiversity hot spots alone can reduce up to 30% of the current rate of species extinction.
1. The hotspots of biodiversity are the safe and richest region on biodiversity, especially for those species threatened by humans, so their protection could reduce the current rate of extinction....
What does ‘Red’ indicate in the IUCN Red List (2004)?
In the IUCN Red List, the ‘Red’ indicates the species which are endangered and is at a very high risk of going extinct.
According to David Tilman, the greater the diversity, the greater is the primary productivity. Can you think of a very low diversity man-made ecosystem that has high productivity?
1. The agricultural fields are excellent examples of man-made nature. 2. This is known to show very low variability but the output is very high.
What accounts for the greater ecological diversity of India?
The great diversity of ecology in India is due to geographical diversity with various geographical features, e.g. Deserts, rain forests, mangroves, coral reefs, wetlands, estuaries and mountain...
What could have triggered mass extinctions of species in the past?
Causes for mass extinction of species in the past: 1. Natural disasters such as volcanic eruptions, floods, droughts etc. 2. Due to temperature changes 3. Due to the fall of sea level
What characteristics make a community stable?
Characteristics for a stable community: 1. Slight variations in annual production 2. Resistance to occasional interruptions 3. Resistance to external attacks
Which of the following group exhibit more species diversity?
a. Gymnosperms b. Algae c. Bryophytes d. Fungi Answer: d. Fungi Explanation: The fungi is a group of eukaryotic heteromorphic organisms with various forms, sizes, physiology, and reproductive mode....
What is common to the techniques (i) in vitro fertilisation, (ii) Cryo preservation and (iii) tissue culture?
a. All are in situ conservation methods. b. All are ex-situ conservation methods. c. All require ultra-modern equipment and large space. d. All are methods of conservation of extinct organisms...
The historic convention on Biological Diversity held in Rio de Janeiro in 1992 is known as:
a. CITES Convention b. The Earth Summit c. G-16 Summit d. MAB Programme Answer: b. The Earth Summit Explanation: The UNCED, also known as the Rio de Janeiro Earth Summit, Rio Summit, Rio Conference,...
Which of the below-mentioned regions exhibit less seasonal variations?
a. Tropics b. Temperates c. Alpines d. Both (a) & (b) Answer: a. Tropics Explanation: A tropical rain forest is a biome that occurs in regions with high temperatures and high rainfall. This...
The active chemical drug reserpine is obtained from:
a. Datura b. Rauwolfia c. Atropa d. Papaver Answer: b. Rauwolfia Explanation: Reserpine is an indole alkaloid, antipsychotic, and antihypertensive drug used to control high blood pressure and...
Which of the following forests is known as the ‘lungs of the planet Earth’?
a. Taiga forest b. Tundra forest c. Amazon rain forest d. Rain forests of North East India Answer: c. Amazon rain forest Explanation: The Amazon's Tropical Rainforest is known as the planet 'lungs'...
Among the ecosystem mentioned below, where can one find maximum biodiversity?
a. Mangroves b. Desert c. Coral reefs d. Alpine meadows Answer: c. Coral reefs Explanation: A coral reef is an underwater creature. Rivers are composed of colonies of coral polyps held together by...
Which of the following statements is correct?
a. Parthenium is an endemic species of our country. b. African catfish is not a threat to indigenous catfishes. c. Steller’s sea cow is an extinct animal. d. Lantana is popularly known as carrot...
The extinction of passenger pigeon was due to:
a. Increased number of predatory birds. b. Overexploitation by humans. c. Non-availability of the food. d. Bird flu virus infection. Answer: b. Overexploitation by humans Explanation: The main...
What is common to Lantana, Eichhornia and African catfish?
a. All are endangered species of India. b. All are keystone species. c. All are mammals found in India. d. All the species are neither threatened nor indigenous species of India Answer: d. All the...
Which one of the following is an endangered plant species of India?
a. Rauwolfia serpentina b. Santalum album (Sandalwood) c. Cycas beddonei d. All of the above Answer: d. All of the above Explanation: Endangered species are the most endangered species at a very...
Amongst the animal groups given below, which one appears to be more vulnerable to extinction?
a. Insects b. Mammals c. Amphibians d. Reptiles Answer: c. Amphibians Explanation: According to the IUCN regional red listing guidelines, 12% of all the birds species, 23% of all mammals species,...
The one-horned rhinoceros is specific to which of the following sanctuary
a. Bitar Kanika b. Bandipur c. Kaziranga d. Corbett park Answer: c. Kaziranga Explanation: Kaziranga National Park is a name that reflects the popular conservation efforts of endangered species such...
What is common to the following plants: Nepenthes, Psilotum, Rauwolfia and Aconitum?
a. All are ornamental plants b. All are phylogenic link species c. All are prone to overexploitation d. All are exclusively present in the Eastern Himalayas. Answer: c. All are prone to...
Match the animals given in column I with their location in column II:
Column IColumn IIA. Dodoi. AfricaB. Quaggaii. RussiaC. Thylacineiii. MauritiusD. Stellar’s sea cowiv. Australia Column IColumn IIA. Dodoiii. MauritiusB. Quaggai. AfricaC. Thylacineiv. AustraliaD....
Which one of the following is not a major characteristic feature of biodiversity hot spots?
a. A large number of species b. An abundance of endemic species c. Mostly located in the tropics d. Mostly located in the Polar Regions Answer: c. Mostly located in the tropics Explanation: The...
Where among the following will you find pitcher plant?
a. The rain forest of North-East India b. Sunderbans c. The Thar Desert d. Western Ghats Answer: a. The rain forest of North-East India. Explanation: Nepenthes khasiana is a type of pitcher plant...
Which of the following is not an invasive alien species in the Indian context?
a. Lantana b. Cynodon c. Parthenium d. Eichhornia Answer: b. Cynodon Explanation: Non-native species are species that can enter the external ecosystem and compete with habitat, food and other...
Which of the following is not a cause for loss of biodiversity?
a. Destruction of habitat b. Invasion by alien species c. Keeping animals in zoological parks d. Over-exploitation of natural resources Answer: c. Keeping animals in zoological parks. Explanation:...
Which of the following countries has the highest biodiversity?
a. Brazil b. South Africa c. Russia d. India Answer: a. Brazil Explanation: Brazil is one of the world's most biologically diverse countries. One tenth of the world's species live here. India is in...
Can you think of a situation where we deliberately want to make a species extinct? How would you justify it?
Yes, there has been such a situation in which various parasites and microorganisms may need to be eradicated from the earth. Scientists are working hard to eradicate this parasite as these insects...
The species diversity of plants (22 per cent) is much less than that of animals (72 per cent). What could be the explanations to how animals achieved greater diversification?
There is a significant difference in the percentage of plant species (22%) and animal species (72%). The reasons for this difference are, 1. Adapting of animals in changing environments for survival...
Among the ecosystem services are control of floods and soil erosion. How is this achieved by the biotic components of the ecosystem?
The ecosystem consists of two types of substances. They are the abiotic and the biotic elements. While the abiotic components are air, light, water, temperature, soil, etc., the biotic components...
What are sacred groves? What is their role in conservation?
The Sacred groves are known as the tracts of forest restored in the places of worship. These are found in the Western Ghats of Karnataka, Rajasthan, Maharashtra, Madhya Pradesh, and Meghalaya. These...
How is biodiversity important for ecosystem functioning?
Importance of Biodiversity: 1. An ecosystem is more stable when it has a high species diversity when compared to a low species diversity ecosystem. 2. Higher biodiversity causes the environment to...
What are the major causes of species losses in a geographical region?
Biodiversity is the diversity of species found in different ecosystems including the diversity observed in living species from various sources such as air, water and land. However, the world's...
What is the significance of the slope of regression in a species-area relationship?
The slope is very helpful in finding local habitat relationships. Analysis of the geographical relationship in the sub-regions reveals that the rates of recurrence slopes are the same regardless of...
Give three hypotheses for explaining why tropics show the greatest levels of species richness.
As tropical areas receive more solar energy compared to tropical areas, it leads to a higher variety and higher productivity 2. Tropical regions have minimal seasonal variations and low-density...