[Biodiversity] Meaning and Types of Species+ Mock Questions for CSAT

Environment58 Comments

India Yearbook
  1. What is biodiversity?
  2. Keystone species
  3. Sentinel species: frogs
  4. Blue whales
  5. Non-native species
  6. Vultures and diclofenac
  7. What is biodiversity hotspot?
  8. Plant biodiversity and Green Revolution
  9. Cites: convention on international trade

What is Biodiversity?
Biodiversity = biological diversity. It means number and variety of plants and animals. Consider following example:

  • Jungle a has 10 tigers and 100 deers.
  • Jungle b has 20 tigers in 200 deers.
  • Jungle c has 10 lions and 10 tigers, 100 deers and 100 wild buffalos.

Here jungle c has the most biodiversity. [jungle b also has 220 animals but ‘variety’ is less.] Which of the following statement is true?

  1. Biodiversity is high in isolated islands
  2. Biodiversity is low in tropical forests and coral reefs.
  3. Biodiversity is higher in europe compared to south asia.

Well, All statements are incorrect.

  • Isolated islands have limited number of variety in plants and animals compared to tropical rainforest or coral reefs. Because number of competitors and predators are limited.
  • In the subtropical and polar regions of Northern Hemisphere, the climate is very cold, the region had gone through ice-ages = less population =less competition =less predators =less evolution= less biodiversity of plants and animals (compared to African or Brazilian jungle)
  • In general, you will find less variety in plant and animal species in some European country (Ukraine) compared to a tropical country like Vietnam.
  • So, As you move from equator towards the poles, biodiversity decreases. (latitudes)

Talking about Europe, almost all plans eaten today in Europe have originated in the developing countries around the equator.

  • Coffee: Ethiopia
  • Rice: India
  • Wheat: turkey and Afghanistan
  • Soya, cucumber, orange: china

Q. Consider the following statements (UPSC CSAT-2011)
1. Biodiversity is normally greater in the lower latitudes as compared to the higher latitudes.
2. Along the mountain gradients, biodiversity is normally greater in the lower altitudes as compared to the higher altitudes.
Which of the statements given above is/are correct?
(a.) 1 only
(b.) 2 only
(c.) Both 1 and 2
(d.) Neither 1 nor 2
ans. 1st statement is true. (europe vs africa).

Second statement is true. Higher you go= colder atmosphere = less biodiversity.

Keystone species

  • These species determine the ability of a large number of other species to survive.
  • When the keystone species becomes extinct. It has snowballing (=cascading) effect on extinction of other species (just like increase in petrol price on inflation)
  • Examples of keystone species
    • Bees : pollination of fruits and flowers. Albert Einstein once said, “if the honeybee goes extinct, we have four more years on earth”.
    • Plankton : food of many fishes

Sentinel species: frogs

  • They are sensitive indicators of environmental problem.
  • For example, frogs, toads, salamander. They are amphibians (can live in both land and water).
  • Frogs breath through their moist skin, which is very sensitive to pollutants in environment.
  • In amphibians, fertilization is typically external, meaning that the sperm and egg join outside of the female’s body.
  • They lay unprotected eggs (without shell like chicken egg) in water or moist damp places, so their eggs are also very vulnerable to pollution, temperature, humidity change etc.
  • Thus, a rapid decline in the population of frogs thus would indicate a looming environmental problem.
  • (Homework) difference between coldblooded and warm blooded animals.

Blue whales

  • Largest mammals on Earth. Elephents are the largest mammals on land only.
  • International whaling commission (IWC) was set up in 1946 to fix anyone hunting quotas for the countries. Since 1980s IWC called for a halt on whale poaching
  • But Japan, Norway and Ireland are major countries that still continue to indulge in whale hunting, they are unhappy with IWC and cites restrictions.

Q. Which of the following Statements are true?

  • 1.Construction of large dam will increase the biodiversity in the area.
  • 2.Fish and Amphibians are cold-blooded animals.
  • 3.Whale is a cold-blooded fish.
  • 4.Whale dives out of water to regulate its body temperature
  • 5.Polar bear is a cold blooded animal because it goes in hibernation.

Non-native species

  • For example, in the 18th century, rabbits introduced in Australia for sport shooting.
  • Since they were a non-native species in Australia, it meant they had no predators or competitors to control their population. They destroyed a vast range of plants and reduced the forest area.
  • Rats of several species were unintended stowaways* on oceanic voyages, and thus spread around the world.
  • Infected humans took the human immunodeficiency virus (HIV), which caused aids from Africa to the rest of the world.
  • Stowaways= a person who hides aboard a ship or plane in the hope of getting free passage

Bird : Another Sentinel Species

  • Birds are very important for seed dispersal, insect and rodent control, scavenging (vultures), and pollination.
  • Many birds are also sentinel species e.g.Vultures
  • Colombia has more than 1800 species of birds = most bird-diverse country
  • India’s got about 1250 =we rank in top-10 in terms of bird diversity.

Vultures and Diclofenac

  • Diclofenac is a painkiller medicine used mostly for arthritis in humans
  • Veternary Diclofenac is used on cattle, as painkiller, stopping inflammation and fever.
  • When Animals are treated with Diclofenac, this drug keeps accumulating in their body. When these animals die, Vultures eat them = kidney failure =death of vulture.
  • Hence Government of India banned Veternary Diclofenac. Now farmers have to use other expensive drugs instead of Diclofenac.
  • Bigger Why should we care? Let the vultures die! What difference does it make to us or to the environment ?
  • Well, Less vultures= more dead animals for dogs to eat = dog population increases = more problem of rabies.
  • Secondly, vulture’s digestive system can destroy many parasites, but dog’s digestive system cannot. Hence dogs who eat dead animals are more disease carriers than vultures.

What is biodiversity hotspot?

  • It is an area unusually rich in biodiversity of birds and animals, but they are under constant threat of overexploitation. Such an area is called a biodiversity hotspot
  • Example of biodiversity hotspots in India : eastern Himalayas, western Ghats. (more in separate articles)

Plant biodiversity and Green Revolution

  • But under the green revolution program, the government introduced HYV (high yielding variety) seeds. So, instead of 30,000 indigenous varieties of rice, now Indian farmers plant only 12 HYV rice varieties.= reduced biodiversity of rice.

Cites: convention on international trade in endangered animals and plant species.

  • The illegal smuggling of rare species, exotic pets (orangutan), ornamental plants (orchid, cactus) is estimated to be $8 billion per year, which is second only to the illegal weapons smuggling.
  • Cites convention restricts the trade of endangered plants and animals and also the trade of clothing, food, medicine, and souvenirs, produced out of these species.
  • Cites is a step by world’s oldest global environmental organization IUCN = international union for conservation of nature and natural resources (iucn), hq: Switzerland.
  • The same ICUN maintains the red list of threatened species.

Q. Which of the following statements are true?

  • 1.Introduction of high yielding verity of seeds increases biodiversity.
  • 2.“Green Revolution” has increased biodiversity in India.
  • 3.CITES convention regulates the whale poaching.
  • 4.CITES is a convention made by UNESCO.
  • 5.Western Himalaya and Eastern Ghats are examples of biodiversity hotspots.

Mrunal recommends

  1. (free) NCERT, NIOS, TN-Books
  2. Environment by ShankarIAS
  3. Indian Polity M.Laxmikanth (Hindi | English)
  4. Art & Culture by Nitin Singhania (Hindi | English)
  5. Spectrum: Modern History (Hindi | English)
  6. Bipin Chandra: Post Independence
  7. Fast-track to Arithmetic Rajesh Verma
  8. MK Pandey’s Analytical Reasoning
  9. Disha’s Topicwise Paperset (Hindi | English)
  10. School Atlas
  11. Mains: Language papers
  1. (free) NCERT, NIOS, TN-Books 4 History,Geo,Sci
  2. Indian Polity M.Laxmikanth (Hindi | English)
  3. Spectrum: Modern History (Hindi | English)
  4. Maths: Quantam CAT Sarvesh Kumar
  5. Objective General English SP Bakshi
  6. Word Power made Easy -Norman Lowe
  7. Topic wise Solved Paperset by Disha


So far 58 Comments posted

  1. Unknown

    How come this statement can be false..?
    "Biodiversity is normally greater in the lower latitudes as compared to the higher latitudes"

    You only have written that regions near equator (Lower latitude) are more diverse than regions near poles (Higher latitude).

    Please explain

    1. Harikrishnan

      What? Prepare extra hard for english paper please.

      1. Harikrishnan

        Sorry my mistake… But he wrote it as true not false… So i read your comment as true.. So sorry

  2. amitoj

    Thanks for guiding us with this superb blog sir..
    I have one confusion in this article..
    You commented that "As you move from equator towards the poles, biodiversity decreases. (latitudes)", then how come the first statement of the CSAT 2011 question is incorrect?
    Correct me if m wrong…

  3. Mrunal Patel || મૃણાલ પટેલ

    you're right. I mistakenly read the question statement as "Biodiversity is normally lower in the lower latitudes" and hence said "false". thanks for the correction.

  4. Mrunal Patel || મૃણાલ પટેલ

    you're right. I mistakenly read the question statement as "Biodiversity is normally lower in the lower latitudes" and hence said "false". thanks for the correction.

  5. Nishat

    Last question : None of the above is correct….. Am i right sir?

  6. mahendra

    Interval 1:
    2 and 4 are correct…

  7. Nilesh Gawade

    Thanks for the blog, Sir.

  8. mahendra

    Interval 2: 5 AND 4 ….

  9. Sunil Sharma

    Awesome Mrunal.
    I wish our teachers learn from you.

  10. Nishat

    @Mahendra: Bro i think u r wrong…. how come 4 and 5 are correct in interval 2….
    none of them is correct dude…. check ur answer again…

  11. MOOKAMBIKA

    please give a notes on bitarnika and gahirmata biodiversity hotspots

  12. Balamurali Krishna

    Cold blooded (CB) and warm blooded (WB) animals?????

    CB & WB are terms that refer to how an animal regualtes it's temperature.

    Warm blooded animals maintain a constant body temperature via internal (or endothermic) methods, like shivering, sweating, panting and storing and burning fat. In other words, hair and body fat help to insulate the body to slow heat loss, and evaporation of surface moisture cools the body.

    Animals that fall into this category include:

    Mammals Cats Dogs Humans(including ur gf) Giraffes Elephants Bears Beavers Chickens Monkeys
    Badgers moose deer cows calf wolf fox squirl skunck roosters Birds

    Cold Blooded animals use external means to control their body temperature. These ectothermic methods include basking in the sun, hiding in the shade, changes in metabolic rate. Some animals' body temperature even change with their environment. In other words, Cold-blooded animals are not able to regulate internally their body temperatures — their body temperature tends towards the temperature of their surroundings.

    Animals that fall into this category are:

    Fish Insects Spiders Frogs Snakes Geckos Alligators Crocodiles Chameleons
    Toads Turtles Sharks (both reptiles and amphibian are included in this category)

    Difference between Reptiles and Amphibians????

    There are several anatomical (pertaining to body structure) and reproductive differences between reptiles and amphibians. Reptiles include alligators, crocodiles, turtles, and snakes. Amphibians include salamanders, toads, and frogs.

    One difference between the two is the structure of their outer skin. Reptiles are covered with scales, shields, or plates, and their toes have claws. Amphibians, on the other hand, have moist, glandular skins, and their toes lack claws.

    The eggs of reptiles have a thick, hard shell that protects the developing embryo from moisture loss, even on dry land. In contrast, the eggs of amphibians lack a hard outer covering and, thus, must be laid in water or in damp places.

    Finally, young reptiles are miniature replicas of their parents in general appearance, although not always in coloration and pattern. Juvenile amphibians, however, pass through a larval (wormlike), usually aquatic, stage before they metamorphose (change in form and structure) into the adult form.

  13. Balamurali Krishna

    yes 2 is 100% right and 1,3,5 are 100% wrong,

    i m not sure about 4 (since i don live with whales) but i hope with these statements one can eliminate the answer options in prelims..

    1 ——> will decrease biodiverity

    3 ——> whale is a mammal (without sweat gland), mammals lie in warm blood category

    5 ——> Bear is warm blooded animal. During hibernation these animals live off of stored body fat and can drop their body temperatures by as much as 50 degrees Fahrenheit.

    mrunal sir, plz tell d ryt answers.. {{{ computer ji lock kiya jaye }}}}

  14. Balamurali Krishna

    I too agree.. none is correct!

    1. amit

      4.Whale dives out of water to regulate its body temperature

      FRnd i thnk it dives out to breath o2 after which it goes in hibernation…but that can be said as mechanism 2 regulate…kindly temme the ans to ds

  15. swaroop

    good work mrunalji……….

  16. vijayManikanta

    CITES =the Convention on International Trade in Endangered Species of Wild Fauna and Flora, also known as the Washington Convention

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  19. KAPIL

    hi Mrunal plz send me link of all the items related to environment and biodiversity

  20. JUGGERNAUT

    hi mrunal… ur doing yeoman service to aspirants.. great.. but one point.. you have told that biodiverssity is less on islands.. arent islands booming centres of ENDEMISM… take madagascar or australia or our very own narcondam island… arent they biodiverse…

  21. vikas

    Doesn’t Biodiversity and Biodiversity Hotspot Include diversity In Plants as only Birds and Animals have been mentioned above
    Class 11th Geog Last Chapter mentions Plants in Biodiversity and Mentioned that Hotspot Classification is based on vegetation.
    Kindly lp[lp[5glplg[lplo-l-l-r3o- solve the confusion

    1. vikas

      confusion only related to hotspot

  22. shaz

    interval 2:

    only 3 is right

    sir kindly tel the right answers sir

  23. Simran

    Interval 1 : Only 2 correct. Not sure about 4.

    Interval 2: Non correct.

    Please confirm, Mrunal.

    1. raghavendra

      interval 1 :- i am sure whale is warm blooded animal , if it is warm blooded animal why does it have to jump outside to regulate its own temperature ….i think 4 is wrong

      1. Ravneet

        Whale comes out to intake oxygen as it is a mammal, whale doesnt have gills

  24. raghavendra

    interval 1 :- only 2 is corrrect

    interval 2 :- all are false

  25. sangamesh

    please provide information about mangrove

  26. nilesh

    sir can you provide the exact number of Biodiversity hotspot that india have?
    is it “two” or “three”

    1. love shandilya

      2 bio diversity hotspots in india
      western ghats
      eastern himalyas
      but 4 in south asia
      above 2 and
      srilanka
      indoburma= india n myanmar

      1. love shandilya

        sry these r 3 indo burma also included in hotspots in india

    2. Nirvana

      in some books its mentioned 2/3 but as per ministry of environment and forest GOI, there are 4 hotspots;
      western ghats, himalayas, indo burma and sunda islands (it includes the southern most nicobar islands)
      u can check for confirmation

  27. priti

    intervl:only 1 is crct.
    in interval 2 :only 3 is crct.
    and sir rice is the native crop of china as res .c leong and other sources.thnk u sir for ur selfless effoerts for stds like me ;reallly appreciable 🙂

  28. Nallathambi.P

    sir, the polar bears are warm blooded animals.

  29. Tiru

    None of the above is correct, right?

  30. Divya

    1.Introduction of high yielding verity of seeds increases biodiversity.
    2.“Green Revolution” has increased biodiversity in India.
    3.CITES convention regulates the whale poaching.
    4.CITES is a convention made by UNESCO.
    5.Western Himalaya and Eastern Ghats are examples of biodiversity hotspots.

    None of the above is right!

  31. ashutosh

    sir plz provide the link for basic of ecology and environment,

  32. ashutosh

    sir plz provide the link for basics of ecology and environment.

  33. Neha Raturi

    Hello sir,
    Sir iam not in a habbit of reading newspaper daily which irritate me. also i want to know that memorise all this stuff… please guide me ………

  34. lokesh

    sir, u have mentioned bird as sentinel species, how do they determine environment problem

  35. Sumanth

    It’s Iceland , along with Norway, Japan and not Ireland which has objected to IWC’s 1982 moratorium on commercial whaling.

  36. Arun Krishnan

    Their isolation and high availability of empty niches leads to increased speciation. As a result, island ecosystems comprise 30% of the world’s biodiversity hotspots, 50% of marine tropical diversity, and some of the most unusual and rare species.

  37. Abhishek

    Sir pls send answer of interval 1 and 2

  38. KRISHNA

    follow this site you will gradually develop habit of reading general studies

  39. praveen awasthi

    mrunal sir u are really great…whatever u right goes directly in the mind.so lucid manner..thank u so much…….

  40. Achin

    What is Biodiversity Megahotspot

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  42. jayraj

    The same ICUN maintains the red list of threatened species.

    Please sir correct it to IUCN as it can produce confusion among readers.

    Thank you

  43. Siddhartha

    Are you blind ? Where it’s written that the mentioned statement is false? Both statements are true…

  44. poonam khandelwal

    thanks a ton sir!!! short of words

  45. Ayushi

    1.Construction of large dam will increase the biodiversity in the area —> false
    2.Fish and Amphibians are cold-blooded animals. —-> true
    3.Whale is a cold-blooded fish.—>false
    4.Whale dives out of water to regulate its body temperature
    5.Polar bear is a cold blooded animal because it goes in hibernation.—->false

  46. ayushi

    Which of the following statements are true?

    1.Introduction of high yielding verity of seeds increases biodiversity.—->false (it improves quality)
    2.“Green Revolution” has increased biodiversity in India.—–>true
    3.CITES convention regulates the whale poaching.—>false
    4.CITES is a convention made by UNESCO.—->false
    5.Western Himalaya and Eastern Ghats are examples of biodiversity hotspots.—> true

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