Free Forest Ecology MCQs with Answers

• A. Upright
• B. Linear
• C. Irregular
• D. Inverted

Explanation: In a grassland, numerous grasses support fewer herbivores, which in turn support still fewer carnivores, so the pyramid of numbers is…

• A. Decomposers
• B. Producers
• C. Tertiary consumers
• D. Primary consumers

Explanation: In the usual grazing food chain, producers form the largest population because they are the first and most numerous trophic level…

• A. Only the plants
• B. Only the living organisms
• C. Both biological and non-biological processes
• D. Only the animals

Explanation: The carbon cycle includes biological processes such as photosynthesis, respiration and decomposition, as well as non-biological processes…

• A. Law of limiting factors
• B. Liebig's law of minimum
• C. Laws of thermo dynamics
• D. Shelford's law of tolerance
• E. Biogenetic law

Explanation: Energy flow in living systems follows the first and second laws of thermodynamics: energy is conserved but becomes progressively less…

• A. Only the herbivores will die
• B. All the animal will die
• C. Only the carnivores will die
• D. It will not matter to anyone because chemosynthetic bacteria will produce food for all

Explanation: Green plants are the main producers and energy entry point for most food chains, so their disappearance would eventually deprive…

• A. Grasshopper, rat, snake
• B. Grasshopper, frog, snake
• C. Millipedes, centipedes, sparrow
• D. Earthworm, hen, rat

Explanation: A valid sequence is green plants → grasshopper → frog → snake → hawk, with each organism serving as food for the next.

• A. A producer
• B. A primary consumer
• C. A tertiary consumer
• D. A secondary consumer

Explanation: The lamb is a herbivore and therefore a primary consumer; the crocodile becomes a secondary consumer when it eats the lamb.

• A. Food web
• B. Predator-prey relationship
• C. Succession
• D. Pyramid of numbers

Explanation: A pyramid of numbers represents the numbers of organisms at successive trophic levels, usually showing many prey supporting fewer…

• A. The end of the food chain and are decomposers
• B. Second link of the food chain and are herbivorous
• C. Third link of the food chain and are tertiary consumers
• D. First link of the food chain and are known as primary producers

Explanation: Bacteria break down dead animals and return nutrients to the environment, so they function as decomposers at the terminal stage of the…

• A. Web of food
• B. Food chain
• C. Biomass
• D. Interdependence

Explanation: A plant being eaten by a herbivore and then by a carnivore shows a linear transfer of food and energy, which is a food chain.

• A. Secondary consumers
• B. Producers
• C. Primary consumers
• D. Top consumers in this food chain

Explanation: Phytoplankton are producers, and water fleas feed on them, placing the water fleas at the first consumer level as primary consumers.

• A. Productivity control
• B. Food chain mechanism
• C. Any of these
• D. Feedback mechanism

Explanation: Feedback mechanisms regulate populations because changes in producers affect consumers, while consumer pressure feeds back to control…

• A. Chemical cycle
• B. Biogeochemical cycle
• C. Geological cycle
• D. Geochemical cycle

Explanation: A biogeochemical cycle moves an element between living organisms and nonliving components such as soil, water and the atmosphere.

• A. Carnivores
• B. Secondary consumers
• C. Primary consumers
• D. Primary producers

Explanation: Most zooplankton feed on phytoplankton, so they occupy the primary-consumer level in aquatic food chains.

• A. All the atmospheric gases
• B. Only carbon, hydrogen and oxygen
• C. All the above components
• D. Energy only

Explanation: The main contribution from outer space to an ecosystem is solar energy, which powers photosynthesis and therefore most ecosystem food…

• A. Three types
• B. Two types
• C. Four types
• D. Five types

Explanation: The three standard ecological pyramids are pyramids of numbers, biomass and energy.

• A. Food chains
• B. Food web
• C. Both (a) & (b)
• D. None of the above

Explanation: An ecosystem contains feeding relationships that can be represented as individual food chains, while interconnected chains form a food…

• A. Tropical rainforest
• B. Temperate grassland
• C. Tropical deciduous forest
• D. Desert shrub

Explanation: Primary productivity depends strongly on water availability, and desert shrubs are limited by severe aridity.

• A. Free energy
• B. Potassium
• C. Nitrogen
• D. Carbon

Explanation: Free energy enters ecosystems mainly as sunlight and is degraded as heat during transfers, so it flows in one direction.

• A. Scavenger
• B. Herbivore
• C. Carnivore
• D. Saprophyte

Explanation: Primary consumers obtain their energy directly by eating producers, so they are herbivores.