Euglenids possess a pellicle, a collection of microtubules, under their cell membrane that provides support and flexibility. Describe and explain how living Euglena moves. Do the cells alter their shape as they move? Do the cells seem flexible? Can you see the flagella? Try adding some Détain or Protoslo to your slide to slow them down.
The correct answer and explanation is:
Correct Answer:
Living Euglena moves using a whip-like structure called a flagellum, which pulls the organism through the water. Euglena is also capable of a unique movement called euglenoid movement, where the cell changes shape as it glides. Yes, the cells alter their shape during this movement and appear very flexible due to the pellicle under their membrane. With proper lighting and magnification, you can see the flagella, especially after adding Détain or Protoslo to slow them down.
300-Word Explanation:
Euglena is a single-celled, freshwater organism that exhibits both plant-like and animal-like features. Its movement is especially interesting because it uses two main forms of locomotion. The primary method is through a long whip-like tail called a flagellum, which extends from the front of the cell. This flagellum rotates or lashes, pulling the Euglena forward through its watery environment. The movement is smooth and directed, allowing the organism to swim toward light or nutrients.
However, Euglena is not limited to flagellar movement. It also demonstrates a rare form of mobility known as euglenoid movement or metaboly. During this movement, the entire cell alters its shape, appearing to contract and expand as it moves. This shape-changing ability is made possible by the pellicle, a flexible structure formed by protein strips supported by microtubules located just beneath the cell membrane. The pellicle gives the cell both support and flexibility, allowing it to bend and twist as it moves through dense or viscous environments.
When observing Euglena under a microscope, especially if they are swimming quickly, the flagella can be difficult to see. Adding substances like Détain or Protoslo helps by slowing down the cells without killing them. This makes it easier to observe the flagellum and the body’s shape changes. The flagellum may appear as a thin thread moving in a whip-like motion at the front of the cell.
In summary, Euglena moves using both a visible flagellum and flexible body movements. The pellicle plays a key role in allowing these organisms to remain mobile and adaptable.