Question

the great oxidation event (goe) occurred around 2.4 billion years ago when oxygen levels in earths atmosphere significantly increased.
the goe is largely attributed to the proliferation of cyanobacteria, which produce oxygen through photosynthesis.
this increase in atmospheric oxygen allowed for the development of more complex life forms that require oxygen for survival.
however, the goe also led to mass extinctions of anaerobic organisms that thrived in oxygen-poor environments.
the oxygen-rich atmosphere eventually led to the formation of the ozone layer, which protects earth from harmful solar radiation.

the student wants to highlight the positive and negative ecological impacts of the great oxidation event. which choice most effectively uses relevant information from the notes to accomplish this goal?

choose 1 answer:

a the great oxidation event, occurring around 2.4 billion years ago, caused mass extinction of anaerobic organisms due to the development of more complex life forms.

b the proliferation of cyanobacteria during the great oxidation event not only led to an increase in atmospheric oxygen, but also to the development of the ozone layer.

c the great oxidation event enabled the development of complex aerobic life forms while causing mass extinctions of anaerobic organisms.

d following the great oxidation event, the formation of the ozone layer provided protection from harmful solar radiation, fostering a more habitable environment on earth.

Explanation:

Analyze the student's goal

The prompt asks to highlight both the positive and negative ecological impacts of the Great Oxidation Event (GOE).

Evaluate the options

Using the Rhetorical Synthesis knowledge point:

• (A) focuses on the negative impact (mass extinction) but incorrectly attributes it to the development of complex life forms, and fails to clearly present a positive ecological impact.
• (B) mentions two positive outcomes (increase in oxygen, development of the ozone layer) but lacks any negative impact.
• (C) explicitly presents a positive impact (development of complex aerobic life forms) and a negative impact (mass extinctions of anaerobic organisms).
• (D) only highlights positive outcomes (formation of the ozone layer, protection from radiation, habitable environment).

Select the best choice

Option (C) is the only choice that successfully balances and highlights both the positive and negative ecological impacts.

Answer:

• (A) The Great Oxidation Event, occurring around 2.4 billion years ago, caused mass extinction of anaerobic organisms due to the development of more complex life forms.
• (B) The proliferation of cyanobacteria during the Great Oxidation Event not only led to an increase in atmospheric oxygen, but also to the development of the ozone layer.
• (C) The Great Oxidation Event enabled the development of complex aerobic life forms while causing mass extinctions of anaerobic organisms. (Correct answer)
• (D) Following the Great Oxidation Event, the formation of the ozone layer provided protection from harmful solar radiation, fostering a more habitable environment on Earth.