Cyanobacteria threaten humans and wildlife. But these algal blooms may also have a good side. Which two details from the text show this?
A These tiny life forms made Earth’s first breathable air.
B Slimy green algae can easily take over a lake.
C They feed on nitrogen and not phosphorous.
D Huge algal blooms fertilized by iron pull greenhouse gases out of the atmosphere.
E Scientists think didymo has been there all along in its harmless state.
Cyanobacteria threaten humans and wildlife. But these algal blooms may also have a good side. Which two details from the text show this?
Share
The correct answers are:
A) These tiny life forms made Earth’s first breathable air.
D) Huge algal blooms fertilized by iron pull greenhouse gases out of the atmosphere.
Explanation:
Detail A highlights the historical significance of cyanobacteria in producing oxygen, which is essential for life on Earth. Detail D emphasizes the positive role of algal blooms in sequestering greenhouse gases, contributing to climate regulation. Both details show that despite the potential threats posed by cyanobacteria, they have beneficial aspects as well.