Question

case study
the green river valley
the green river valley is home to a diverse ecosystem, including fish, amphibians, birds, small mammals, and a variety of plants. over the past decade, a new factory was built upstream, and chemical runoff began entering the river.
as a result:

• some fish populations declined sharply.
• frogs and other amphibians became less common.
• certain plants near the riverbank died off.
• birds and mammals that relied on fish or plants as food began moving away.

local scientists studied the area and found that the decline in one species caused a chain reaction, affecting multiple organisms and altering the structure of the ecosystem.
the community is now debating whether to implement stricter regulations to reduce pollution and restore the river ecosystem.

6 why is biodiversity important in an ecosystem like the green river valley?
a it provides stability and helps the ecosystem recover from disturbances
b it allows for only one species to dominate
c it prevents sunlight from reaching aquatic plants
d it increases the number of predators only

Explanation:

In an ecosystem like the Green River Valley, biodiversity means having a variety of species. When there's a disturbance (like chemical runoff here), a more diverse ecosystem has different species with different roles. If one species declines (e.g., fish populations), other species with similar functions or that can adapt can help the ecosystem stay stable and recover. Option B is wrong because biodiversity doesn't promote one species domination. Option C is incorrect as biodiversity doesn't prevent sunlight from reaching plants. Option D is wrong since biodiversity affects all trophic levels, not just predators. So A is correct as it matches the role of biodiversity in ecosystem stability and recovery.

Answer:

A. It provides stability and helps the ecosystem recover from disturbances