Showing 91–100 of 100 questions
in Ecology & Environment
Which of the following is an example of a decomposer in an ecosystem?
A
Grass
B
Earthworm
C
Fungus
D
Deer
Correct Answer:
C. Fungus
EXPLANATION
Fungi are primary decomposers that break down dead organic matter. Earthworms are detritivores, not true decomposers.
The pyramid of numbers is typically inverted in which ecosystem?
A
Grassland
B
Desert
C
Forest with large trees and parasites
D
Aquatic ecosystem
Correct Answer:
C. Forest with large trees and parasites
EXPLANATION
In a forest, one large tree (producer) supports many insects and parasites, creating an inverted pyramid of numbers.
Which of the following represents a density-dependent factor affecting population growth?
A
Earthquake
B
Flood
C
Disease
D
Volcanic eruption
Correct Answer:
C. Disease
EXPLANATION
Disease transmission increases with population density, making it a density-dependent factor. Natural disasters are density-independent.
What is the process by which plants release water vapor through their leaves?
A
Respiration
B
Transpiration
C
Evaporation
D
Condensation
Correct Answer:
B. Transpiration
EXPLANATION
Transpiration is the release of water vapor by plants through stomata in leaves. Evaporation refers to water bodies.
Which gas is primarily responsible for the greenhouse effect in the atmosphere?
A
Nitrogen
B
Oxygen
C
Carbon dioxide
D
Argon
Correct Answer:
C. Carbon dioxide
EXPLANATION
CO₂ is the major anthropogenic greenhouse gas, comprising about 76% of total greenhouse gas emissions, contributing significantly to global warming.
What is the carrying capacity of an environment?
A
The maximum population size that an environment can sustain indefinitely
B
The minimum population needed for survival
C
The rate of population growth
D
The number of births per year
Correct Answer:
A. The maximum population size that an environment can sustain indefinitely
EXPLANATION
Carrying capacity (K) is the maximum population size an environment can support with available resources without degradation.
Which type of succession occurs on a newly formed volcanic island?
A
Secondary succession
B
Primary succession
C
Tertiary succession
D
Cyclical succession
Correct Answer:
B. Primary succession
EXPLANATION
Primary succession occurs on bare, newly exposed surfaces with no pre-existing soil or organisms, such as volcanic islands.
In a food chain, what percentage of energy is typically transferred from one trophic level to the next?
EXPLANATION
The 10% law states that only about 10% of energy is transferred to the next trophic level; the remaining 90% is lost as heat and used in metabolism.
What is the primary source of energy in most ecosystems?
A
Decomposers
B
Consumers
C
Solar radiation
D
Geothermal energy
Correct Answer:
C. Solar radiation
EXPLANATION
Solar radiation captured by photosynthetic organisms is the primary energy source for almost all ecosystems on Earth.
Which of the following is a biotic component of an ecosystem?
A
Soil
B
Decomposers
C
Water
D
Temperature
Correct Answer:
B. Decomposers
EXPLANATION
Decomposers are living organisms that break down dead matter, making them biotic components. Soil, water, and temperature are abiotic components.
