1. Environmental biology primarily studies:
(A) Structure of DNA only
(B) Interactions of organisms with their environment
(C) Human anatomy only
(D) Chemical reactions in labs
2. Abiotic components of an ecosystem include:
(A) Sunlight, water, temperature, and soil
(B) Plants and animals only
(C) Microbes only
(D) Decomposers only
3. Biotic components include:
(A) Soil and water only
(B) All living organisms
(C) Air only
(D) Minerals only
4. Population in environmental biology refers to:
(A) A group of individuals of the same species living in a habitat
(B) All species in a habitat
(C) Only plants
(D) Only animals
5. Habitat is defined as:
(A) Food chain
(B) Group of species
(C) Place where an organism lives
(D) Energy flow
6. Niche refers to:
(A) Only its population size
(B) Only its habitat
(C) Functional role of a species in an ecosystem
(D) Only its diet
7. Producers are:
(A) Autotrophs that produce organic compounds from sunlight
(B) Herbivores only
(C) Carnivores only
(D) Decomposers only
8. Consumers include:
(A) Water only
(B) Plants only
(C) Microbes only
(D) Organisms that feed on other organisms
9. Decomposers are important because they:
(A) Recycle nutrients back into the ecosystem
(B) Produce sunlight
(C) Consume water only
(D) Absorb oxygen only
10. Primary consumers are:
(A) Omnivores
(B) Carnivores
(C) Detritivores
(D) Herbivores
11. Secondary consumers feed on:
(A) Producers only
(B) Primary consumers
(C) Detritus only
(D) Water only
12. Tertiary consumers feed on:
(A) Microbes only
(B) Producers only
(C) Secondary consumers
(D) Detritus only
13. Ecological pyramids represent:
(A) Trophic structure and energy flow
(B) DNA sequences only
(C) Soil nutrients only
(D) Temperature variations
14. Pyramid of numbers shows:
(A) Nutrient cycling
(B) Total biomass
(C) Energy only
(D) Number of organisms at each trophic level
15. Pyramid of biomass shows:
(A) Number of species only
(B) Total mass of organisms at each trophic level
(C) Energy flow only
(D) Water content only
16. Pyramid of energy shows:
(A) Number of organisms only
(B) Energy flow through trophic levels
(C) Soil nutrients only
(D) Water content only
17. Biogeochemical cycles describe:
(A) Only photosynthesis
(B) Movement of elements through biotic and abiotic components
(C) Only respiration
(D) Protein synthesis only
18. Carbon cycle involves:
(A) Photosynthesis, respiration, and decomposition
(B) Nitrogen fixation only
(C) Sulfur cycle only
(D) Water cycle only
19. Nitrogen fixation is carried out by:
(A) Viruses only
(B) Animals only
(C) Fungi only
(D) Rhizobium and cyanobacteria
20. Denitrification converts:
(A) Nitrogen to ammonia only
(B) Nitrates to nitrogen gas
(C) Proteins to amino acids only
(D) Oxygen to ozone
21. Phosphorus cycle does not include:
(A) Soil and water
(B) Atmospheric phase
(C) Rock weathering
(D) Decomposition
22. Oxygen is replenished in the environment by:
(A) Respiration only
(B) Photosynthesis
(C) Combustion only
(D) Decomposition only
23. Aquatic ecosystems include:
(A) Grasslands only
(B) Deserts only
(C) Forests only
(D) Freshwater and marine ecosystems
24. Freshwater ecosystems include:
(A) Tundra only
(B) Oceans only
(C) Rivers, lakes, ponds, and wetlands
(D) Deserts only
25. Marine ecosystems include:
(A) Oceans, coral reefs, and estuaries
(B) Lakes only
(C) Rivers only
(D) Grasslands only
26. Terrestrial ecosystems include:
(A) Lakes only
(B) Oceans only
(C) Rivers only
(D) Forests, deserts, grasslands, and tundra
27. Biomes are:
(A) Ponds only
(B) Large regions with similar climate, vegetation, and organisms
(C) Desert patches only
(D) Microorganisms only
28. Temperate forests are characterized by:
(A) Deciduous trees and seasonal climate
(B) Cacti and dry conditions
(C) Mangroves only
(D) Tundra vegetation
29. Desert ecosystems have:
(A) Dense forests only
(B) High rainfall only
(C) Coral reefs only
(D) Low rainfall and drought-resistant plants
30. Grasslands are dominated by:
(A) Aquatic plants only
(B) Trees only
(C) Cacti only
(D) Grasses and herbaceous plants
31. Tundra ecosystems are:
(A) Humid tropical forests
(B) Hot and dry
(C) Cold, with permafrost and sparse vegetation
(D) Desert only
32. Coral reefs are formed by:
(A) Calcium carbonate secreting organisms
(B) Trees only
(C) Mangroves only
(D) Cacti only
33. Keystone species are:
(A) Microbes only
(B) Species with no ecological role
(C) Species with a large impact on ecosystem structure
(D) Plants only
34. Invasive species are:
(A) Native species only
(B) Endangered species only
(C) Non-native species that disrupt local ecosystems
(D) Microbes only
35. Ecological succession is:
(A) Soil formation only
(B) Instant species replacement
(C) Gradual change in species composition over time
(D) Photosynthesis only
36. Primary succession occurs on:
(A) Rivers only
(B) Abandoned farmland only
(C) Forest floors only
(D) Bare land with no previous life
37. Secondary succession occurs on:
(A) Deserts only
(B) Newly formed rocks only
(C) Oceans only
(D) Previously inhabited land after disturbance
38. Climax community refers to:
(A) Microbial colony only
(B) Initial stage of succession
(C) Temporary ecosystem
(D) Stable, mature community at the end of succession
39. Biodiversity refers to:
(A) Variety of life in all forms and levels
(B) Only plant species
(C) Only animal species
(D) Only microbial species
40. Genetic diversity is:
(A) Number of ecosystems
(B) Variation in genes within a species
(C) Species diversity only
(D) Soil diversity only
41. Species diversity refers to:
(A) Genetic variation only
(B) Number of species in an area
(C) Ecosystem types only
(D) Soil microorganisms only
42. Ecosystem diversity refers to:
(A) Variety of ecosystems in a region
(B) Number of species only
(C) Number of genes only
(D) Microbial populations only
43. Endangered species are:
(A) At risk of extinction
(B) Abundant species
(C) Keystone species only
(D) Invasive species only
44. Conservation biology aims to:
(A) Sequence DNA only
(B) Produce antibiotics only
(C) Ferment alcohol only
(D) Preserve biodiversity and maintain ecosystem functions
45. Ecological footprint measures:
(A) Biomass only
(B) Energy in food chain only
(C) Human impact on the environment
(D) Soil nutrients only
46. Greenhouse gases include:
(A) CO₂, CH₄, and N₂O
(B) O₂ and N₂ only
(C) H₂O only
(D) NaCl only
47. Global warming is caused by:
(A) Decomposition only
(B) Photosynthesis only
(C) Respiration only
(D) Excess greenhouse gases
48. Acid rain is caused by:
(A) SO₂ and NOₓ emissions
(B) CO₂ only
(C) O₂ only
(D) Water only
49. Ozone layer depletion is due to:
(A) CFCs and halons
(B) CO₂ only
(C) Oxygen only
(D) Nitrogen only
50. Sustainable development aims to:
(A) Focus only on agriculture
(B) Exploit all natural resources
(C) Focus only on industry
(D) Meet current needs without compromising future resources