Connecting Link Between Plants and Animals: Euglena

Introduction:
Euglena is a unicellular organism that belongs to the phylum Euglenozoa. It exhibits characteristics of both plants and animals, making it a connecting link between the two kingdoms. Let's explore why Euglena is considered as a connecting link between plants and animals.

Plant-like Characteristics:
1. Chloroplasts: Euglena possesses chloroplasts, similar to plants, which are responsible for photosynthesis. These chloroplasts contain a green pigment called chlorophyll, enabling Euglena to manufacture its own food through photosynthesis.
2. Starch Storage: Like plants, Euglena stores excess food in the form of paramylon, which is a type of carbohydrate reserve.
3. Flagella: Euglena has one or two flagella that help it move towards light, similar to how plants grow towards sunlight for photosynthesis.

Animal-like Characteristics:
1. Heterotrophic Mode of Nutrition: Euglena can also act as a heterotroph when sunlight is not available. It feeds on organic matter or other small organisms by engulfing them through a process called phagocytosis.
2. Presence of Eyespot: Euglena possesses a light-sensitive structure called the eyespot, which helps it detect the intensity and direction of light. This is similar to how some animals have eyes to perceive their surroundings.
3. Motility: Euglena exhibits motility using its flagella, which is a characteristic feature of many animal species.

Conclusion:
Euglena is considered as a connecting link between plants and animals due to its possession of both plant-like and animal-like characteristics. While it exhibits plant-like features such as chloroplasts, starch storage, and flagella, it also displays animal-like traits such as heterotrophic nutrition, the presence of an eyespot, and motility. This unique combination of characteristics makes Euglena a fascinating organism that bridges the gap between the two kingdoms.