Question

select the correct answer from each drop - down menu.
coral reefs have a symbiotic relationship with algae. because of human activity, the ocean is absorbing high levels of, which causes an increase in ocean temperature. due to these unfavorable conditions, corals expel algae, leading to.

Explanation:

• First blank: Human activities like burning fossil fuels release large amounts of \(CO_2\). The ocean absorbs \(CO_2\), and this absorption is related to ocean - acidification processes. Also, the heat - trapping nature of \(CO_2\) (as part of the greenhouse effect) contributes to ocean temperature increase.
• Second blank: When corals expel the symbiotic algae (zooxanthellae) living within their tissues, the process is called coral bleaching. The algae give corals their color, and without them, the coral's white calcium carbonate skeleton is visible.

Answer:

First blank: \(CO_2\) (carbon dioxide), Second blank: coral bleaching.