MEGA Elementary Education Multi-Content Practice Test

What effect on the biosphere has been observed as a result of increased carbon dioxide in the atmosphere?

1. Increased marine temperatures have resulted in the bleaching of corals

2. Increased amounts of nutrients have led to algal blooms

3. Increased alkalinity has impaired the ability of oysters to form strong shells

4. Increased net productivity of phytoplankton has been measured

The correct answer is: Increased marine temperatures have resulted in the bleaching of corals

The increase in carbon dioxide in the atmosphere contributes to global warming, which in turn raises marine temperatures. Warmer waters can lead to coral bleaching, a phenomenon where corals expel the symbiotic algae (zooxanthellae) living in their tissues. This algae is crucial for the corals' color and energy. When stressed by temperature increases, corals become pale as they lose these vital algae, which can ultimately result in coral mortality if the conditions persist. In this context, the connection between rising carbon dioxide levels, increased atmospheric temperatures, and the resultant impact on marine ecosystems through coral bleaching is well-established scientific evidence. This process affects biodiversity and the overall health of marine habitats, underscoring the intricate relationship between atmospheric changes and the biosphere's wellbeing.