1. Which statement best defines biodiversity?
ⓐ. It is the number of individual organisms present in one habitat.
ⓑ. It is the total biomass produced by plants in an ecosystem.
ⓒ. It is the combined diversity at different levels of biological organisation.
ⓓ. It is the total number of food chains operating in a community.
Correct Answer: It is the combined diversity at different levels of biological organisation.
Explanation: Biodiversity is a broad concept that includes variation at more than one biological level. It covers genetic differences within species, differences among species, and differences among ecosystems. Because it includes all these levels together, it cannot be reduced to only population size or biomass. This wider meaning makes biodiversity central to understanding living variety on Earth.
2. The term “biodiversity” was popularised by
ⓐ. Edward Wilson
ⓑ. Charles Darwin
ⓒ. Robert May
ⓓ. Alexander von Humboldt
Correct Answer: Edward Wilson
Explanation: Edward Wilson is widely associated with bringing the term “biodiversity” into common scientific use. The idea refers to the total variety of life considered across different biological levels. Knowing the name helps connect the term with its formal scientific framing. It also distinguishes the concept from older, narrower ways of describing biological variety.
3. Which pair is correctly matched?
ⓐ. Genetic diversity — variety of ecosystems in a region
ⓑ. Species diversity — variation among strains of rice
ⓒ. Ecological diversity — variation in reserpine content within one species
ⓓ. Genetic diversity — variation among strains of rice
Correct Answer: Genetic diversity — variation among strains of rice
Explanation: Genetic diversity refers to variation within a species. Different strains of rice belong to the same crop species, but they differ genetically in important traits. By contrast, species diversity deals with the variety of species, and ecological diversity deals with the variety of ecosystems. Matching the example to the correct level is essential because these three levels are related but not identical.
4. Variation in reserpine content among different populations of Rauwolfia vomitoria is an example of
ⓐ. ecological diversity
ⓑ. genetic diversity
ⓒ. species diversity
ⓓ. community diversity
Correct Answer: genetic diversity
Explanation: Rauwolfia vomitoria shows differences within the same species, not between different species or ecosystems. Such intraspecific variation reflects differences in genes across populations. Chemical traits like reserpine content can therefore reveal genetic diversity. This is why the example is used to show variation within a species rather than variation among habitats.
5. Protection of biodiversity requires conservation of
ⓐ. genetic, species, and ecological diversity
ⓑ. cellular, tissue, and organ diversity
ⓒ. structural, functional, and behavioural diversity
ⓓ. terrestrial, aquatic, and aerial diversity
Correct Answer: genetic, species, and ecological diversity
Explanation: The main levels of biodiversity are genetic diversity, species diversity, and ecological diversity. These levels represent variation within species, among species, and among ecosystems. Conserving only one level gives an incomplete picture of biological richness. Effective conservation therefore aims to preserve all three together.
6. Which statement correctly distinguishes genetic diversity from species diversity?
ⓐ. Genetic diversity compares ecosystems, whereas species diversity compares genes.
ⓑ. Genetic diversity is measured only in forests, whereas species diversity is measured only in grasslands.
ⓒ. Genetic diversity concerns variation within a species, whereas species diversity concerns variety among species.
ⓓ. Genetic diversity occurs only in wild organisms, whereas species diversity occurs only in domesticated organisms.
Correct Answer: Genetic diversity concerns variation within a species, whereas species diversity concerns variety among species.
Explanation: The difference lies in the level at which variation is being considered. Genetic diversity exists among individuals or populations of the same species, while species diversity refers to the number and variety of different species in an area. Confusing these two levels leads to wrong interpretation of examples. A crop with many varieties shows genetic diversity, not species diversity.
7. A plant breeder preserves over 50,000 rice strains mainly to safeguard
ⓐ. only the number of species in a field
ⓑ. only the area under cultivation
ⓒ. only the age of the crop plant
ⓓ. variation within a species
Correct Answer: variation within a species
Explanation: Different rice strains represent differences within the same species. Those differences provide a pool of useful traits such as disease resistance, yield stability, or tolerance to stress. Such variation is the essence of genetic diversity. Preserving it is valuable because it supports adaptation, selection, and long-term crop improvement.
8. Which example best represents species diversity?
ⓐ. Several strains of rice grown in one region
ⓑ. Different amphibian species found in one mountain region
ⓒ. Different populations of Rauwolfia showing chemical variation
ⓓ. Different ecosystem types present within one country
Correct Answer: Different amphibian species found in one mountain region
Explanation: Species diversity refers to the variety of species present in a given area. When the example speaks of different amphibian species, the comparison is among species rather than within one species. Rice strains and Rauwolfia populations show genetic diversity instead. Different ecosystem types would represent ecological diversity.
9. Different populations of the same medicinal plant may show different medicinal value mainly because
ⓐ. every ecosystem produces identical genes
ⓑ. all individuals in one species are chemically uniform
ⓒ. gene-level variation can alter important traits within a species
ⓓ. species diversity always removes intraspecific differences
Correct Answer: gene-level variation can alter important traits within a species
Explanation: Traits such as chemical composition can vary because populations carry different genetic combinations. That variation may change the quantity of useful compounds produced by the same species. The Rauwolfia example is important for this reason. It shows that biodiversity at the genetic level can have practical biological and medicinal significance.
10. Which statement about biodiversity is correct?
ⓐ. It is not limited to counting species alone.
ⓑ. It refers only to the number of ecosystems in a country.
ⓒ. It refers only to variation in inherited characters.
ⓓ. It excludes differences found within a species.
Correct Answer: It is not limited to counting species alone.
Explanation: A common mistake is to treat biodiversity as if it means only species richness. In reality, biodiversity also includes genetic variation within species and ecological variation among habitats and communities. Species count is important, but it is only one part of the larger idea. The broader definition is what makes the concept biologically meaningful.
11. The presence of about 1,000 varieties of mango mainly illustrates
ⓐ. species diversity
ⓑ. genetic diversity
ⓒ. ecological diversity
ⓓ. habitat diversity
Correct Answer: genetic diversity
Explanation: Mango varieties belong to the same species but differ in inherited characteristics such as flavour, size, colour, or growth traits. Such variation within a species is a classic example of genetic diversity. The example does not refer to multiple species or multiple ecosystems. It shows how much biological variety can exist even before moving beyond a single species.
12. Loss of ecological diversity would most directly mean loss of
ⓐ. different genes within a single species
ⓑ. different varieties within a crop plant
ⓒ. different populations of the same organism
ⓓ. different habitats and ecosystem types in a region
Correct Answer: different habitats and ecosystem types in a region
Explanation: Ecological diversity refers to the variety of ecosystems, habitats, and communities present in an area. When this level declines, the region loses different kinds of environmental settings rather than just genes or species identities. Forests, wetlands, grasslands, and deserts together reflect ecological diversity. Its loss reduces the range of living conditions that support many forms of life.
13. Which example best shows intraspecific variation across the geographical range of a single species?
ⓐ. Different ecosystem types present in one country
ⓑ. Different populations of Rauwolfia vomitoria showing variation in reserpine content
ⓒ. Greater amphibian richness in one mountain chain than another
ⓓ. Presence of coral reefs, wetlands, and alpine meadows in one region
Correct Answer: Different populations of Rauwolfia vomitoria showing variation in reserpine content
Explanation: Intraspecific variation means variation within the same species. Rauwolfia vomitoria remains one species, but its populations differ in the amount of reserpine they contain. That difference reflects genetic diversity spread across its distributional range. The other options describe diversity among ecosystems or among species rather than within one species.
14. Which pair is correctly matched?
ⓐ. Genetic diversity — deserts, mangroves, and coral reefs in one country
ⓑ. Ecological diversity — different varieties of mango within one species
ⓒ. Species diversity — variation in reserpine content among Rauwolfia populations
ⓓ. Species diversity — greater amphibian richness in Western Ghats than in Eastern Ghats
Correct Answer: Species diversity — greater amphibian richness in Western Ghats than in Eastern Ghats
Explanation: Species diversity refers to variation in the number and kinds of species in a region. A comparison of amphibian richness between Western Ghats and Eastern Ghats is therefore a species-level comparison. Genetic diversity would involve variation within a single species, such as rice strains or mango varieties. Ecological diversity would involve differences among ecosystems like deserts, wetlands, and forests.
15. Which country is used as an example of high ecosystem diversity because it includes deserts, rain forests, mangroves, coral reefs, wetlands, estuaries, and alpine meadows?
ⓐ. India
ⓑ. Greenland
ⓒ. Colombia
ⓓ. Norway
Correct Answer: India
Explanation: India is used as a strong example of ecological diversity because many very different ecosystem types occur within its boundaries. These include dry deserts, tropical rain forests, mangroves, coral reefs, wetlands, estuaries, and alpine meadows. Such variety shows diversity at the ecosystem level rather than only at the species level. It highlights how one country can contain many contrasting ecological settings.
16. Which of the following best illustrates ecological diversity?
ⓐ. Presence of many varieties of mango in cultivation
ⓑ. Chemical variation among populations of a medicinal plant
ⓒ. Occurrence of deserts, estuaries, wetlands, and coral reefs in one country
ⓓ. Greater number of amphibian species in one hill region than another
Correct Answer: Occurrence of deserts, estuaries, wetlands, and coral reefs in one country
Explanation: Ecological diversity refers to the variety of habitats, communities, and ecosystem types in a region. A country containing deserts, estuaries, wetlands, and coral reefs clearly shows ecosystem-level variation. Mango varieties and chemical variation within one species belong to genetic diversity. A difference in amphibian richness between two regions is a species-diversity example.
17. The statement “Western Ghats have greater amphibian diversity than Eastern Ghats” refers mainly to
ⓐ. genetic diversity
ⓑ. species diversity
ⓒ. ecological diversity
ⓓ. physiological diversity
Correct Answer: species diversity
Explanation: The comparison is based on how many different amphibian species occur in the two regions. That makes it a species-diversity statement rather than a genetic one. Genetic diversity would compare variation within one amphibian species, not among many amphibian species. Ecological diversity would compare ecosystem types rather than species richness.
18. A region contains tropical rain forests, mangroves, coral reefs, wetlands, estuaries, and alpine meadows. This most directly indicates high
ⓐ. genetic isolation
ⓑ. species extinction
ⓒ. population uniformity
ⓓ. ecological diversity
Correct Answer: ecological diversity
Explanation: The listed features are all different kinds of ecosystems. Their coexistence in one region shows diversity of habitats and ecological settings. That is the core meaning of ecological diversity. It does not directly measure gene variation within a species or the number of species present in each ecosystem.
19. Which statement best explains why thousands of rice strains are considered evidence of biodiversity?
ⓐ. They represent inherited variation within a single crop species.
ⓑ. They show that rice occurs in many different ecosystems.
ⓒ. They prove that rice has more species than most plant groups.
ⓓ. They show that rice is found only in tropical countries.
Correct Answer: They represent inherited variation within a single crop species.
Explanation: Different strains of rice belong to one crop species but differ in inherited traits. Such variation within a species is the essence of genetic diversity. These differences may affect yield, resistance, maturity, or tolerance to environmental stress. Preserving many strains is therefore important because it protects the genetic resource base of the crop.
20. Which option is the best example of genetic diversity?
ⓐ. Greater amphibian species richness in Western Ghats than Eastern Ghats
ⓑ. Presence of deserts and mangroves within the same country
ⓒ. About 1,000 varieties of mango found within one country
ⓓ. Large number of bird species in a tropical forest
Correct Answer: About 1,000 varieties of mango found within one country
Explanation: Many mango varieties reflect variation within a single species, so this is a genetic-diversity example. The focus is on inherited differences among varieties, not on multiple species or multiple ecosystems. In contrast, amphibian richness and bird richness refer to species diversity. Deserts and mangroves in one country illustrate ecological diversity.
