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CHAPTER 13 BIODIVERSITY AND CONSERVATION 13.1 Biodiversity If an alien from a distant galaxy were to visit our planet 13.2 Biodiversity Conservatio... |
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| Class XII |
Biology |
Biology |
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deserts, rain forests, mangroves, coral reefs, wetlands, estuaries, and alpine meadows has a greater ecosystem diversity than a Scandinavian countr... |
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| Class XII |
Biology |
Biology |
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about 7 million. Reprint 2026-27 BIOLOGY Letuslookatsomeinterestingaspectsaboutearth’sbiodiversitybased on the currently available species inventor... |
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| Class XII |
Biology |
Biology |
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figures, we estimate that there are probably more than 1,00,000 plant species and more than 3,00,000 animal species yet to be discovered and descri... |
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| Class XII |
Biology |
Biology |
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about tropics that might account for their greater 219 biological diversity? Ecologists and evolutionary biologists have proposedvarioushypotheses;... |
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| Class XII |
Biology |
Biology |
13 |
tropical forests of different continents, the slope is found to be 1.15. What do steeper slopes mean in this context? 220 13.1.3 The importance of ... |
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| Class XII |
Biology |
Biology |
13 |
Paul Ehrlich. In an airplane (ecosystem) all parts are joined together using thousands of rivets (species). If every passenger travelling in it sta... |
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| Class XII |
Biology |
Biology |
13 |
a study of the history of life on earth through fossil records, we learn that large-scale loss of species like the one we are currently witnessing ... |
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| Class XII |
Biology |
Biology |
13 |
probably millions of species is being cut and cleared for cultivating soyabeansor for conversion to grasslands for raising beef cattle. Besides tot... |
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| Class XII |
Biology |
Biology |
13 |
extinction of the other. 13.2 B IODIVERSITY C ONSERVATION 13.2.1 Why Should We Conserve Biodiversity? There are many reasons, some obvious and othe... |
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| Class XII |
Biology |
Biology |
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bulbul’s song in the morning. Can we put a price tag on such things? The ethical argument for conserving biodiversity relates to what we owe to mil... |
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| Class XII |
Biology |
Biology |
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regions. Although all the biodiversity hotspots put together cover less than 2 per cent of the earth’s land area, the number of species they collec... |
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| Class XII |
Biology |
Biology |
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and its conservation is therefore a collective responsibility of all nations. The historic Convention on Biological Diversity (‘The Earth Summit’) ... |
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| Class XII |
Biology |
Biology |
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that communities with high diversity tend to be less variable, more productive and more resistant to biological invasions. Earth’s fossil history r... |
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| Class XII |
Biology |
Biology |
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world? Reprint 2026-27 BIODIVERSITY AND CONSERVATION 3. Give three hypotheses for explaining why tropics show greatest levels of species richness. ... |
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| Class XII |
Biology |
Biology |
4 |
females; these are the autosomes. A pair of X-chromosomes are present in the female, whereas the presence of an X and Y chromosome are determinant ... |
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| Class XII |
Biology |
Biology |
3 |
CHAPTER 3 REPRODUCTIVE HEALTH 3.1 Reproductive Health – Problems and Strategies 3.2 Population Explosion and You have learnt about human reproducti... |
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| Class XII |
Biology |
Biology |
3 |
schools should also be encouraged to provide right information to the young so as to discourage children from believing in myths and having misconc... |
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| Class XII |
Biology |
Biology |
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the foetus. Research on various reproduction-related areas are encouraged and supported by governmental and non-governmental agencies to find out n... |
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| Class XII |
Biology |
Biology |
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the government was forced to take up serious measures to check this population growth rate. Themostimportantsteptoovercomethisproblemistomotivatesm... |
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| Class XII |
Biology |
Biology |
3 |
the child fully, chances of conception are almost nil. However, this method has been reported to be effective only upto a maximum period of six mon... |
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| Class XII |
Biology |
Biology |
3 |
the uterus and the Cu ions released suppress sperm motility and thefertilisingcapacityofsperms.ThehormonereleasingIUDs,inaddition, Reprint 2026-27 ... |
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| Class XII |
Biology |
Biology |
3 |
Medical Termination of Pregnancy preventconception.Sterilisationprocedureinthemaleiscalled‘vasectomy’ (Amendment) Act, 2017 and that in the female,... |
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| Class XII |
Biology |
Biology |
3 |
of pregnancy before full term is called the pregnancy would medical termination of pregnancy (MTP) or induced abortion. Nearly involve a risk to th... |
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| Class XII |
Biology |
Biology |
4 |
following terms with example (a) Co-dominance (b) Incomplete dominance 14. What is point mutation? Give one example. 15. Who had proposed the chrom... |
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