Free Man and His Environment MCQs with Answers

11. In evergreen coniferous trees, presence of small, waxy and needles-like leaves is significant to:

• A. Allow snow to build up on their branches
• B. Produce more wind resistance in cold season
• C. Capture maximum sunlight for photosynthesis
• D. Reduce water loss by evaporation during cold season

Explanation: The waxy coating and needle-like shape help reduce water loss by evaporation during cold season.So option D is correct.Other characteristics are not related to small, needle like leaves, waxy coating in coniferous trees.

12. In addition to frequent fires the factors that maintain grass land biome are:

• A. Acidic soil and low rainfall
• B. High temperature and acidic soil
• C. High rainfall and low temperature
• D. Low rainfall and grazing by animals

Explanation: Grassland biomes are maintained by several factors including low rainfall, which limits tree growth and encourages grasses to thrive. Grazing by animals is another crucial factor as it helps control plant growth and maintain the grassland ecosystem. While high temperatures are common in grasslands, acidic soils are not typical. Hence, the correct answer is low rainfall and grazing by animals. Other options are incorrect because they either include conditions not typical to grasslands or are incomplete in describing factors that maintain the biome.

13. The given diagram shows the location of biomes on the globe.The biome X is identified as

• A. tundra
• B. grassland.
• C. temperate rain forest.
• D. temperate deciduous forest

Explanation: Area labelled X is Greenland(Denmark). The Greenland biome is primarily characterized by a tundra biome with a central polar ice cap. So option A is correct. Option B,C and D do not represent the biome marked.

14. Organism of same species inhabiting in space and time form a

• A. Population
• B. Species
• C. Community
• D. Biosphere

Explanation: A population is a group of organisms of the same species that live in the same area at the same time.

15. Crumpled leaves like structure are found in_ stage of xerarch succession

• A. Crustose lichen
• B. Foliose-lichen
• C. Moss
• D. Herbaceous

Explanation: In this stage the lichens are just like crumpled leaves attached at one point. It produces shade to the crustose lichens as a result of which their growth is reduced or decreased.

16. Which of the following is environmental buffer?

• A. Wild life
• B. Lichens
• C. Herbs
• D. Forest

Explanation: Forests are complex ecosystems characterized by dense vegetation, including trees, shrubs, herbs, and understory plants. Forests serve as important environmental buffers by regulating climate, conserving soil and water resources, mitigating erosion, and providing habitat for diverse wildlife species. They also play a crucial role in carbon sequestration, helping to mitigate climate change by absorbing and storing atmospheric carbon dioxide. Forests are essential for maintaining ecological balance and supporting the health and well-being of both natural and human communities.

17. The diagram shows an aquatic food web. Which one of the following statement is correct?

• A. There are two producers and three herbivores.
• B. There are two primary consumers and two secondary consumers.
• C. There are three producers and two primary consumers.
• D. There are two herbivores and two tertiary consumers.

Explanation: It is correct because there is 2 producers which are phytoplankton and seaweeds and 3 herbivores which eat them.

18. Nitrogen cycle in nature is depicted in the following flowing flow chart.Which option shows denitrification?

• A. A
• B. B
• C. C
• D. D

Explanation: D shows denitrification. Denitrification is a microbial process in which nitrate (NO₃⁻) is converted back into nitrogen gas (N₂) or nitrous oxide (N₂O) under anaerobic conditions. This process helps to return nitrogen gas to the atmosphere, completing the nitrogen cycle and preventing the accumulation of excess nitrates in the environment.

19. Due to lightning, a forest was set on fire and destroyed. The type of succession which will occur then is termed as

• A. Xerach
• B. Secondary
• C. Hydrarch
• D. Primary

Explanation: Secondary succession happens when a climax community or intermediate community is impacted by a disturbance. This restarts the cycle of succession, but not back to the beginning-soil and nutrients are still present.

20. In Nitrogen cycle, conversion of Nitrates into nitrogen is termed as

• A. Ammonification
• B. Assimilation
• C. Nitrification
• D. Denitrification

Explanation: Denitrification is the process that converts nitrate to nitrogen gas, thus removing bioavailable nitrogen and returning it to the atmosphere.