Find out what do the terms ‘algal bloom’ and ‘red-tides’ signify.
Algal bloom refers to the rapid growth of cyanobacteria (blue-green algae) that often form blooms in polluted water bodies. These organisms are unicellular, colonial or filamentous, and the colonies are generally surrounded by a gelatinous sheath.
Red-tides signify a phenomenon where red dinoflagellates (such as Gonyaulax) undergo such rapid multiplication that they make the sea appear red. The toxins released by such large numbers of dinoflagellates may even kill other marine animals like fishes.
Explanation
The answer draws directly from two sections of the textbook. Algal blooms are mentioned in section 2.1.2 under Eubacteria, specifically regarding cyanobacteria forming blooms in polluted water. Red-tides are explained in section 2.2.2 under Dinoflagellates, where red dinoflagellates like Gonyaulax multiply rapidly and cause the sea to appear red, releasing toxins harmful to marine life.
Solution Steps
Step 1: Identify the definition of algal bloom from the Eubacteria section - cyanobacteria forming blooms in polluted water bodies.
Step 2: Identify the definition of red-tides from the Dinoflagellates section - rapid multiplication of red dinoflagellates making the sea appear red.
Step 3: Combine both definitions into a structured 2-mark answer with proper terminology.