Question

Which species of green algae, commonly known as stonewort, is often mistaken for a plant?

• A. Chara
• B. Kelp
• C. Gracilaria
• D. Sargassum

Answer 1

Answer:

A. Chara

Chara: The Algae Often Mistaken for a Plant

General Characteristics:

• Chara is a genus of charophyte green algae, commonly referred to as stoneworts.

• These algae are multicellular and exhibit a level of structural complexity that often leads to them being mistaken for true plants.

• Unlike true plants, Chara lacks true roots, stems, and leaves. Its structures are analogous but not homologous to plant organs.

• They possess a central axis (like a stem) with whorls of branchlets (like leaves) at regular intervals, and rhizoids at the base (like roots) for anchorage.

Habitat and Distribution:

• Chara species are typically found in freshwater environments, preferring still or slow-moving water.

• They often inhabit shallow lakes, ponds, and slow streams where sunlight can penetrate to the bottom.

• Some species can tolerate brackish water conditions.

• The genus has a widespread global distribution.

Ecological Significance:

• Chara plays a vital role in aquatic ecosystems. It helps to oxygenate the water and provides habitat and food for various aquatic organisms like fish and invertebrates.

• The calcium carbonate deposits that often encrust stonewort give it a rough, brittle texture and contribute to the formation of calcareous sediments. This characteristic gives them the name "stoneworts."