An example of colonial alga isA. SpirogyraB. ChlorellaC. VolvoxD. Ulothrix

The correct answer is: C) Volvox
A colonial alga refers to an alga that exists as a group of individual cells that are physically connected and often work together to carry out the life processes. The colony can be made up of thousands of individual cells, with some cells specialized for reproduction and others for locomotion or nutrition.
1. Volvox:
• Volvox is a well-known example of a colonial alga. It consists of a spherical colony made up of thousands of individual cells.
• Each cell in the colony has two flagella (tail-like structures) that help the colony move through water.
• The cells in Volvox are interconnected by a gel-like matrix, and some cells are specialized for reproduction, while others are specialized for movement.
• The colony of Volvox can be considered as an advanced form of colonial organization in algae, with both vegetative cells and reproductive cells working together to ensure the survival and propagation of the colony.
2. Why Other Options Are Incorrect:
• A) Spirogyra:
o Spirogyra is a filamentous alga, not a colonial alga. It consists of long, unbranched chains of cells, but these cells are not organized into a colony like in Volvox. Instead, they form long filaments.
• B) Chlorella:
o Chlorella is a unicellular green alga that exists as individual cells, not as a colony. Each Chlorella cell functions independently, and it does not form colonies of cells.
• D) Ulothrix:
o Ulothrix is another filamentous alga, like Spirogyra. It forms long chains of cells arranged end to end, rather than creating a colony of interconnected cells.
Volvox is the classic example of a colonial alga, where many individual cells work together as part of a colony. Therefore, the correct answer is C) Volvox.