Chrysophytes, Definition, Types, Characteristics, and Structure

Chrysophytes , often called golden algae, are a group of microorganisms belonging to the kingdom Protista. These unicellular or colonial organisms are predominantly found in freshwater and marine environments. Chrysophytes are primarily photosynthetic, which means they can make their own food using sunlight, similar to plants. However, unlike plants, they do not have specialized roots, stems, or leaves.

Free Study Material for NEET Preparation

Definition of Chrysophytes

Characteristics of Chrysophytes

• Chrysophytes primarily include flagellates from the classes Chrysophyceae and Synurophyceae.
• They are characterized by heterokont flagella (two different types of flagella).
• Chrysophytes have yellow accessory pigments that assist in photosynthesis and give them a golden color.
• They form silicified endogenous resting stages called stomatocysts, which help them survive in unfavorable conditions.
• Around 1,200 species of Chrysophytes have been described so far.
• Many Chrysophytes are mixotrophic, meaning they use both photosynthesis and ingestion of bacteria and small algae to obtain nutrients.

Cell Structure of Chrysophytes

Body Structure and Organization

Types of Chrysophytes

• Diatoms : Known for their unique silica cell walls, diatoms are a primary part of the phytoplankton community and play an essential role in aquatic ecosystems.
• Desmids : A subgroup of green algae, desmids are found mainly in freshwater. They have distinctive, often symmetrical shapes, making them easily recognizable.

Explore - NEET Online Courses by PW

Reproduction of Chrysophytes

• Binary Fission : In this process, a single cell divides into two identical cells, which is the most common mode of reproduction.
• Spore Formation: Under unfavorable conditions, Chrysophytes can form spores that protect them until conditions improve.

 Significance of Chrysophytes

• Diatoms serve as primary producers in aquatic ecosystems, meaning they are a crucial food source for various marine organisms.
• By performing photosynthesis, they contribute significantly to the oceanic food chain, supporting a wide range of marine life.
• In temperate climates, Chrysophytes play a significant ecological role as primary producers in spring, supporting aquatic food webs. Their presence in large numbers during this season supports a variety of aquatic organisms, which rely on them as a food source.
• The presence and diversity of Chrysophytes can serve as indicators of water quality and ecological health.
• Diatoms, a subgroup of Chrysophytes, have significant industrial applications. Their silica-rich cell walls are used to produce diatomaceous earth, which serves as a filtration aid, abrasive, and in various other applications such as pest control.
• Chrysophytes are of interest in scientific research for studying evolutionary biology, ecology, and environmental science.

MCQs of Chrysophytes

Q1. Which one of the following is a characteristic feature of chrysophytes?

1. They are parasitic forms which cause disease in animals
2. They have a protein-rich layer called pellicle
3. They include diatoms
4. They are saprophytic protists

Q2. Chief ‘producers’ in the oceans are;

1. Chrysophyte.
2. Euglenoids.
3. Desmids.
4. Diatoms.

Q3. Diatom shell is made of;

1. silica.
2. lime.
3. magnesium carbonate.
4. none of these.

Answers of MCQs of Chrysophytes