Human influences on the environment

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Question 21
Medium

The passage describes the ecological consequences of human activities on aquatic systems and terrestrial habitats.

Complete the passage by writing a suitable word or words on each dotted line.

The leaching of artificial chemical ................................................................ from agricultural fields into rivers triggers a process called ................................................................ . This nutrient enrichment causes a rapid accumulation of algae on the water surface, forming an algal ................................................................ .

This layer blocks sunlight, meaning submerged plants cannot perform ................................................................ and consequently die. Saprobiontic ................................................................ decompose the dead organic matter, using up dissolved ................................................................ in the water during aerobic respiration. This causes other aquatic organisms, such as fish, to die from lack of oxygen.

On land, the intensive clearing of trees, known as ................................................................ , significantly reduces ................................................................ , which normally returns water vapour to the atmosphere. Furthermore, without tree roots to stabilise the ground, the soil is vulnerable to ................................................................ by wind and rain. This degradation of the physical environment can lead to a severe loss of biodiversity within the terrestrial ................................................................ .

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Human influences on the environment Questions

  1. IGCSE
  2. /Biology
  3. /Human influences on the environment