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100 questions in this collection · Page 1 of 10
Question 1 of 100
📘 CLASS XII
Biodiversity And Conservation
Consider the following statements regarding the species diversity of major taxonomic groups of organisms on Earth:
I. There are more than 20,000 species of ants on our planet. II. Beetles are represented by approximately 3,00,000 species. III. There are nearly 30,000 species of orchids. IV. Fishes comprise about 28,000 species.
Which of the statements given above are correct?
According to NCERT, there are more than 20,000 species of ants, about 3,00,000 species of beetles, about 28,000 species of fishes, and nearly 20,000 species of orchids. Therefore, statement III is incorrect while statements I, II and IV are correct.
Question 2 of 100
📘 CLASS XII
Biodiversity And Conservation
Read the following statements about the term biodiversity:
I. It describes the combined diversity at all levels of biological organization. II. The term was popularized by the eminent sociobiologist Edward Wilson. III. Heterogeneity exists only at the species and genetic levels, but not at the macromolecular level within cells.
Which of the statements given above is/are correct?
Edward Wilson popularized the term biodiversity to describe the combined diversity at all levels of biological organization, ranging from macromolecules within cells to biomes. Hence statement III is incorrect, while statements I and II are correct.
Question 3 of 100
📘 CLASS XII
Biodiversity And Conservation
Consider the following statements regarding genetic diversity:
I. A single species might show high diversity at the genetic level over its distributional range. II. The medicinal plant Rauwolfia vomitoria growing in different Himalayan ranges shows variation in the potency and concentration of the active chemical reserpine. III. India has more than 1,000 genetically different strains of rice and 50,000 varieties of mango.
Which of the statements given above are correct?
India has more than 50,000 genetically different strains of rice and about 1,000 varieties of mango. Statement III reverses these figures and is therefore incorrect. Statements I and II are correct.
Question 4 of 100
📘 CLASS XII
Biodiversity And Conservation
With reference to species and ecological diversity, identify the correct statements:
I. The Western Ghats have a greater amphibian species diversity than the Eastern Ghats. II. Ecosystem diversity in Norway is much greater than that in India due to Norway's unique alpine biomes. III. Ecological diversity represents biological heterogeneity at the ecosystem level.
Which of the following is correct?
Statement II is incorrect because India possesses much greater ecosystem diversity than Norway, including deserts, rain forests, mangroves, coral reefs, wetlands, estuaries and alpine meadows. Statements I and III are correct.
Question 5 of 100
📘 CLASS XII
Biodiversity And Conservation
Study the following statements regarding global species inventories and estimates:
I. According to the IUCN (2004), the total number of plant and animal species described so far is slightly more than 1.5 million. II. Species inventories are significantly more complete in tropical countries than in temperate countries. III. Robert May estimated the global species diversity at about 7 million.
Which of the statements given above are correct?
Statement II is incorrect because species inventories are generally more complete in temperate countries than in tropical countries. Statements I and III are correct.
Question 6 of 100
📘 CLASS XII
Biodiversity And Conservation
Read the following statements regarding the proportion of major taxa in global biodiversity:
I. Animals comprise more than 70 per cent of all recorded species. II. Plants (including algae, fungi, bryophytes, gymnosperms and angiosperms) comprise no more than 22 per cent of the total. III. Among animals, insects are the most species-rich taxonomic group, making up more than 70 per cent of the animal total.
Which of the statements given above are correct?
All three statements are correct. Animals constitute more than 70% of recorded species, plants (including algae, fungi, bryophytes, gymnosperms and angiosperms) account for no more than 22%, and insects form more than 70% of all animal species.
Question 7 of 100
📘 CLASS XII
Biodiversity And Conservation
Consider the following statements about fungal and vertebrate species diversity:
I. Fungi are more species-rich than all vertebrate species combined. II. The number of fungi species is more than the combined total of fishes, amphibians, reptiles and mammals. III. Conventional taxonomic methods show that fungi comprise exactly 22 per cent of global animal species.
Which of the statements given above are correct?
Statements I and II are correct because fungi outnumber all vertebrate species combined. Statement III is incorrect because fungi are not animals, and the 22% figure refers to the broader plant grouping used in NCERT, not animal species.
Question 8 of 100
📘 CLASS XII
Biodiversity And Conservation
Why do global estimates of biodiversity exclude figures for prokaryotes? Consider the following statements:
I. Conventional taxonomic methods are not suitable for identifying microbial species. II. Many prokaryotic species are simply not culturable under laboratory conditions. III. If biochemical or molecular criteria are accepted for delineating species, prokaryotic diversity might run into millions.
Which of the statements given above are correct?
All three statements are correct. Conventional taxonomic methods are inadequate for identifying microbial species, many prokaryotes cannot be cultured in laboratories, and if molecular or biochemical criteria are used, prokaryotic diversity may run into millions of species.
Question 9 of 100
📘 CLASS XII
Biodiversity And Conservation
Study the statements regarding India's share of global biodiversity:
I. India has only 2.4 per cent of the world's land area. II. India's share of the global species diversity is an impressive 8.1 per cent. III. India is recognized as one of the 12 mega diversity countries of the world.
Which of the statements given above are correct?
All three statements are correct. Although India occupies only 2.4% of the world's land area, it harbours about 8.1% of global species diversity and is one of the 12 mega-diversity countries.
Question 10 of 100
📘 CLASS XII
Biodiversity And Conservation
Read the following statements about the recorded species in India:
I. Nearly 45,000 species of plants have been recorded from India. II. The number of recorded animal species in India is twice the number of plant species. III. Applying Robert May's global estimate, only about 22 per cent of India's total species have been recorded so far.
Which of the statements given above are correct?
All three statements are correct. India has about 45,000 recorded plant species and nearly 90,000 recorded animal species. Based on Robert May's estimate, these represent only about 22% of the total species expected to occur in India.