Question

1. a factory is releasing large amounts of pollutants into a nearby river. the runoff contains nutrients, which is causing algae to grow and cover the surface of the river. which of the following is one way this will affect plant life in the river? a. the algae will block sunlight and cause a decrease in the variety of aquatic plants. b. the excess nutrients will cause an increase in the number of plants growing in the river. c. the excess nutrients will attract new species into the area, causing plant populations to decrease. d. the algae will increase the amount of carbon dioxide in the water, reducing the variety of aquatic plants.

Explanation:

Aquatic plants need sunlight for photosynthesis. When algae cover the river surface due to nutrient - rich runoff, they block sunlight, which can lead to a decrease in the variety of aquatic plants. Excess nutrients don't necessarily lead to an increase in plant numbers as the algae overgrowth can be detrimental. Attracting new species doesn't directly cause plant populations to decrease in this context, and while algae can affect gas levels, the main issue here is light blockage.

Answer:

A. The algae will block sunlight and cause a decrease in the variety of aquatic plants.