Question 15 of 18intermediate💡 UnderstandShort Answer3 marks

What are the major causes of species losses in a geographical region?

Correct Answer

The major causes of species losses in a geographical region are:

  1. Habitat loss and fragmentation: Destruction of natural habitats, particularly tropical rain forests due to deforestation and over-exploitation of resources, has proved disastrous for biodiversity.

  2. Over-exploitation: Merciless hunting and poaching of animals like tigers, elephants, rhinoceros, crocodiles, minks and birds for their horn, tusks, and hides has rendered certain species endangered.

  3. Biological invasions (Exotic species): Introduction of species which are not natural inhabitants of the local habitat causes extensive damage to the natural biotic community.

  4. Pollution: Pesticides and pollutants such as hydrocarbons and toxic heavy metals destroy weak and sensitive species.

  5. Co-extinctions: When one species becomes extinct, associated species also face extinction.

  6. Natural calamities: Earthquakes, floods, volcanic eruptions, forest fires, and droughts cause damage to flora and fauna.

Exercise: EXERCISES | Q: 5 | (Page 11)
For More Understanding

Explanation

The textbook context explicitly lists the causes of high extinction rates which include: habitat (particularly forests) loss and fragmentation, over-exploitation, biological invasions and co-extinctions. Additionally, the context mentions natural calamities (earthquakes, floods, volcanic eruptions, forest fires, droughts), pollution (pesticides, hydrocarbons, toxic heavy metals), introduction of exotic species, and poaching/hunting as major causes. The context also notes that present extinction rates are 100 to 1000 times higher due to human activities.

Solution Steps

  1. Step 1: Identify the explicitly stated causes from the text - habitat loss and fragmentation, over-exploitation, biological invasions, co-extinctions

  2. Step 2: Add supporting causes mentioned - natural calamities, pollution, poaching

  3. Step 3: Organize into a structured 3-mark answer with key terms highlighted

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