Question

1. describe evidence the algae in the tank are 600. the decomposition of algae occurs when other organisms perform cellular respiration, decreasing overall dissolved oxygen. - living algae perform photosynthesis, increasing the overall dissolved oxygen. - living algae perform photosynthesis, decreasing the overall dissolved oxygen. cell density - decreases dissolved oxygen overall decrease water color - changes from green to brown.

Explanation:

Step1: Recall algae characteristics

Living algae are green - colored due to chlorophyll and perform photosynthesis which increases dissolved oxygen. Dead algae decompose, other organisms use oxygen for respiration leading to oxygen decrease, and the water color changes as the algae die.

Step2: Analyze given observations

Cell density decreasing can indicate algae death as there are fewer living cells. Overall decrease in dissolved oxygen can be due to algae decomposition. Change from green to brown in water color is a sign that the green - pigmented living algae are dying and decomposing.

Answer:

Cell density decreasing, overall decrease in dissolved oxygen, and change from green to brown in water color are evidence that the algae in the tank are dead.