Question

1 multiple choice 20 points
what is a common negative effect of environmental changes on ecosystems? (dok 1)
plants grow without sunlight.
animals stop moving.
ecosystems always become more stable.
some species may decrease in number or disappear.
2 multiple choice 20 points
which action helps reduce the impact of human activities on ecosystems? (dok 2)
increasing greenhouse gas emissions which helps to make the earth warmer which can increase the speed of the water cycle, thereby increasing the amount of freshwater on earth.
recycling and conserving natural resources which helps increase sustainability of natural resources for future generations.
using more chemical pesticides because this helps keep pests down in the natural ecosystems along with reducing pest impact on crops.
introducing non - native species because these often help increase biodiversity which helps decrease human impact.

Explanation:

For the first question:

• Plants need sunlight for photosynthesis, so "Plants grow without sunlight" is incorrect.
• Animals do not stop moving due to environmental changes in a general sense as described in the option, so "Animals stop moving" is wrong.
• Ecosystems do not always become more stable with environmental changes; in fact, they often face disruptions, so "Ecosystems always become more stable" is incorrect.
• Environmental changes can lead to habitat loss, resource scarcity etc., which can cause some species to decrease in number or disappear.

For the second question:

• Increasing greenhouse gas emissions is harmful (e.g., causes global warming with many negative impacts like sea - level rise, not a positive for ecosystems in general), so the first option is wrong.
• Recycling and conserving natural resources helps in sustainable use, which is beneficial for reducing the negative impact of human activities on ecosystems.
• Using more chemical pesticides can harm non - pest species (e.g., beneficial insects, soil organisms) and disrupt ecosystems, so the third option is wrong.
• Introducing non - native species can often be invasive and cause harm to native species and disrupt the ecosystem (e.g., outcompeting native species for resources), so the fourth option is wrong.

Answer:

1. Some species may decrease in number or disappear.
2. Recycling and conserving natural resources which helps increase sustainability of natural resources for future generations.