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Geography 9th MCQ, All Chapters
Geography 10th MCQ, All Chapters
NCERT Based MCQ with Explanation:
1. What is biodiversity primarily defined as?
(a) The number of ecosystems in a region
(b) The variety of organisms in a specified geographic area
(c) The genetic variation within a single species
(d) The number of endangered species
Explanation: Biodiversity refers to the number and variety of organisms, including plants, animals, and microorganisms, within a specific region. It encompasses species, genetic, and ecosystem diversity, reflecting the richness of life forms.
2. Which factor is the primary cause of weathering mantle variations leading to biodiversity?
(a) Human activities
(b) Input of solar energy and water
(c) Soil composition
(d) Atmospheric pressure
Explanation: Solar energy and water drive weathering processes, creating diverse soil conditions that support varied vegetation. This forms the basis for biodiversity, as different climates foster unique ecosystems and species distributions.
3. How long has biodiversity evolved on Earth according to the chapter?
(a) 1-2 billion years
(b) 2.5-3.5 billion years
(c) 4-5 billion years
(d) 5-6 billion years
Explanation: The chapter states that biodiversity is the result of 2.5-3.5 billion years of evolution. This long period has allowed the development of diverse life forms through natural processes and adaptations.
4. What has caused a rapid decline in biodiversity since the emergence of humans?
(a) Natural disasters
(b) Overuse and extinction
(c) Climate stabilization
(d) Genetic mutations
Explanation: Human activities, such as overuse of resources and habitat destruction, have led to species extinction, causing a rapid decline in biodiversity. This disrupts ecosystems and reduces the variety of life forms.
5. What is the best estimate of the number of species globally?
(a) 2 million
(b) 10 million
(c) 50 million
(d) 100 million
Explanation: The chapter estimates global species numbers between 2 million and 100 million, with 10 million as the best estimate. This reflects the vast, yet uncertain, diversity of life on Earth.
6. Which region is consistently richer in biodiversity?
(a) Polar regions
(b) Temperate regions
(c) Tropical regions
(d) Desert regions
Explanation: Tropical regions, due to favorable climate and resources, support a wide spectrum of biodiversity. The chapter highlights that biodiversity is richer in the tropics compared to polar or temperate regions.
7. What percentage of freshwater fishes in South America are yet to be classified?
(a) 20%
(b) 30%
(c) 40%
(d) 50%
Explanation: The chapter notes that about 40% of freshwater fishes in South America remain unclassified, indicating the ongoing discovery of species and the complexity of cataloging biodiversity in rich ecosystems.
8. What is the average half-life of a species as per the chapter?
(a) 1-4 million years
(b) 5-10 million years
(c) 10-15 million years
(d) 15-20 million years
Explanation: The chapter estimates the average half-life of a species at 1-4 million years, meaning most species persist for this duration before extinction, reflecting the dynamic nature of biodiversity.
9. What percentage of species that ever lived on Earth are extinct today?
(a) 90%
(b) 95%
(c) 99%
(d) 100%
Explanation: The chapter states that 99% of species that ever lived are extinct, highlighting the natural turnover of species over billions of years due to environmental changes and evolution.
10. Which of the following is NOT a level of biodiversity discussed in the chapter?
(a) Genetic diversity
(b) Species diversity
(c) Ecosystem diversity
(d) Population diversity
Explanation: The chapter discusses biodiversity at three levels: genetic, species, and ecosystem diversity. Population diversity is not mentioned as a distinct level, making it the correct exclusion.
Science MCQ, Class 10th, All Chapters11. What does genetic diversity refer to?
(a) Variety of ecosystems
(b) Variation of genes within species
(c) Number of species in an area
(d) Differences between ecosystems
Explanation: Genetic diversity refers to the variation of genes within a species, enabling differences in traits like height or color. This diversity is crucial for healthy breeding and adaptation.
12. Which group do humans genetically belong to?
(a) Homo erectus
(b) Homo sapiens
(c) Homo habilis
(d) Homo neanderthalensis
Explanation: The chapter specifies that humans belong to the Homo sapiens group, with genetic diversity causing variations in physical characteristics, essential for population health and adaptability.
13. What does species diversity measure?
(a) Genetic variations within a species
(b) Number and variety of species in an area
(c) Types of ecosystems
(d) Population size of a species
Explanation: Species diversity measures the richness, abundance, and types of species in a defined area. Areas with high species diversity, like hotspots, support numerous unique organisms.
14. What are areas rich in species diversity called?
(a) Biodiversity zones
(b) Hotspots of diversity
(c) Ecological niches
(d) Genetic pools
Explanation: The chapter defines areas with high species diversity as hotspots of diversity. These regions, often tropical, are critical for conservation due to their rich variety of species.
15. Why is demarcating ecosystem boundaries complex?
(a) Ecosystems are static
(b) Communities and ecosystems have fluid boundaries
(c) Ecosystems lack species diversity
(d) Ecosystems are isolated
Explanation: The chapter explains that ecosystem boundaries are not rigidly defined, as communities and ecosystems overlap and interact, making precise demarcation difficult and complex.
16. Which of the following is an example of ecosystem diversity?
(a) Genetic variation in humans
(b) Grasslands and sholas in a national park
(c) Number of tiger species
(d) Variety of crops
Explanation: Ecosystem diversity involves varied habitats and ecological processes, like grasslands and sholas in Indira Gandhi National Park, as highlighted in the chapter’s example.
17. What role does biodiversity play in human culture?
(a) It restricts cultural development
(b) It shapes genetic and ecological diversity
(c) It has no impact on culture
(d) It only influences economic growth
Explanation: Biodiversity contributes to human culture by shaping genetic, species, and ecological diversity, influencing practices and resource use, as human communities also affect natural diversity.
18. Which ecological role do species play in ecosystems?
(a) They only consume resources
(b) They contribute to ecosystem functions
(c) They prevent nutrient cycling
(d) They reduce ecosystem stability
Explanation: Species perform functions like energy capture, nutrient cycling, and climate regulation, as per the chapter. These roles are vital for ecosystem stability and human survival.
19. How does high biodiversity affect ecosystem stability?
(a) It decreases stability
(b) It has no effect
(c) It increases stability
(d) It causes extinction
Explanation: The chapter states that ecosystems with high biodiversity are more stable, as diverse species enhance resilience to environmental changes, improving the ecosystem’s ability to maintain itself.
20. What is agro-biodiversity also known as?
(a) Genetic diversity
(b) Crop diversity
(c) Ecosystem diversity
(d) Species diversity
Explanation: Agro-biodiversity, or crop diversity, refers to the variety of food crops, as noted in the chapter. It’s a key economic aspect of biodiversity, supporting food security and agriculture.
21. Which economic commodity is NOT directly linked to biodiversity?
(a) Food crops
(b) Medicinal resources
(c) Synthetic chemicals
(d) Forests
22. What is the scientific role of biodiversity?
(a) It provides economic resources
(b) It helps understand life’s evolution
(c) It regulates climate
(d) It supports agriculture
23. Why is it ethically wrong to cause species extinction?
(a) It reduces economic benefits
(b) Every species has an intrinsic right to exist
(c) It only affects humans
(d) It increases biodiversity
24. What is a good indicator of human relationships with other species?
(a) Population growth
(b) Level of biodiversity
(c) Economic development
(d) Technological advancement
25. What has accelerated the loss of biodiversity in recent decades?
(a) Natural evolution
(b) Growth in human population
(c) Species adaptation
(d) Climate stabilization
26. Which regions contain about 50% of Earth’s species?
(a) Polar regions
(b) Temperate forests
(c) Tropical rainforests
(d) Deserts
27. Which natural calamity does NOT directly cause biodiversity loss?
(a) Earthquakes
(b) Volcanic eruptions
(c) Solar flares
(d) Forest fires
28. What are species introduced to a non-native habitat called?
(a) Endemic species
(b) Exotic species
(c) Vulnerable species
(d) Rare species
29. Which animal is listed as hunted for its horn?
(a) Elephant
(b) Rhinoceros
(c) Tiger
(d) Crocodile
30. Which organization classifies threatened species?
(a) World Health Organization (WHO)
(b) International Union for Conservation of Nature (IUCN)
(c) United Nations (UN)
(d) World Wildlife Fund (WWF)
31. What is the IUCN’s Red List primarily about?
(a) Economic resources
(b) Endangered species worldwide
(c) Exotic species
(d) Ecosystem types
32. Which species category is in immediate danger of extinction?
(a) Vulnerable species
(b) Rare species
(c) Endangered species
(d) Exotic species
33. What characterizes vulnerable species?
(a) They are abundant
(b) They face extinction risk if threats continue
(c) They are exotic
(d) They are already extinct
34. What defines rare species?
(a) Large populations worldwide
(b) Small populations in limited areas
(c) High genetic diversity
(d) Widespread distribution
35. Why is biodiversity conservation critical for human existence?
(a) It ensures economic growth
(b) It maintains environmental balance
(c) It prevents natural disasters
(d) It increases population growth
36. What is a key requirement for sustainable biodiversity conservation?
(a) Industrial expansion
(b) Involvement of local communities
(c) Isolation of ecosystems
(d) Increased resource extraction
37. Where was the Convention of Biodiversity signed in 1992?
(a) The UK
(b) Brazil
(c) China
(d) Mexico
38. Which act did the Government of India pass to protect wildlife?
(a) Forest Conservation Act, 1980
(b) Wild Life (Protection) Act, 1972
(c) Environment Protection Act, 1986
(d) Biodiversity Act, 2002
39. How many countries are recognized as mega diversity centers?
(a) 8
(b) 10
(c) 12
(d) 15
40. Which country is NOT a mega diversity center?
(a) Brazil
(b) India
(c) Australia
(d) Russia
41. What primarily defines biodiversity hotspots?
(a) Population density
(b) Vegetation
(c) Climate patterns
(d) Soil types
42. What percentage of Madagascar’s plants and animals are unique?
(a) 65%
(b) 75%
(c) 85%
(d) 95%
43. What threatens biodiversity in the islands of Hawaii?
(a) Volcanic eruptions
(b) Introduced species and land development
(c) Overpopulation
(d) Desertification
44. What is the primary focus of national parks and sanctuaries?
(a) Recreation
(b) Conservation
(c) Hunting
(d) Urban development
45. Which of the following is a role of biodiversity in nutrient cycling?
(a) It prevents nutrient movement
(b) It facilitates nutrient movement
(c) It reduces nutrient availability
(d) It eliminates nutrients
46. What is a consequence of low genetic diversity in a species?
(a) Increased adaptability
(b) Reduced breeding success
(c) Higher population growth
(d) Enhanced ecosystem stability
47. Which ecosystem type is richest in biodiversity?
(a) Deserts
(b) Tropical forests
(c) Tundra
(d) Grasslands
48. What is a major factor in the deterioration of biodiversity?
(a) Sustainable farming
(b) Concept of biological resources
(c) Genetic conservation
(d) Community cooperation
49. Which pollutant is listed as harmful to sensitive species?
(a) Organic fertilizers
(b) Toxic heavy metals
(c) Recycled water
(d) Natural gases
50. What is a key step suggested by the world conservation strategy?
(a) Promote industrial growth
(b) Preserve endangered species
(c) Increase resource extraction
(d) Reduce community involvement