Question

Which of the following is NOT involved in cell migration? (A) Dynein (B) Flagella (C) Actin (D) Centrioles

Short answer

Centrioles are not involved in cell migration.

Step-by-step solution

Identify the Keywords

Understand the key terms in the question: cell migration, Dynein, Flagella, Actin, Centrioles.

Define Cell Migration

Cell migration is the movement of cells from one area to another, which is a critical process in development, immune responses, and wound healing.

Analyze Each Option

Evaluate each given option to see if it is involved in cell migration.

Evaluate Dynein

Dynein is a motor protein that moves along microtubules and is involved in transporting cellular cargo, important for cell division but less directly involved in cell migration.

Evaluate Flagella

Flagella are tail-like structures that some cells use for motility in aqueous environments, not typically involved in the conventional cell migration process seen in tissues.

Evaluate Actin

Actin is a protein that forms microfilaments and is crucial for cell shape and movement, playing a major role in cell migration.

Evaluate Centrioles

Centrioles are involved in cell division and the formation of cilia and flagella but do not directly contribute to cell migration.

Compare Options and Conclude

From the evaluation, it is clear that Dynein, Actin, and Flagella (to an extent) have roles in cell locomotion or structure affecting movement, while Centrioles do not.

Key concepts

Dynein

Dynein is a motor protein that plays a crucial role in cellular function. It moves along microtubules, which are part of the cytoskeleton, and helps transport various cellular cargos. This transportation is vital for several cellular processes, particularly during cell division, where dynein helps to position chromosomes correctly.
However, dynein is not directly involved in cell migration. Cell migration mainly relies on the cytoskeleton's actin filaments rather than the microtubules where dynein operates. Thus, dynein's primary roles are in intracellular transport and mitosis, rather than in the active movement of cells from one location to another.

Flagella

Flagella are long, whip-like structures that protrude from the cell body. They are primarily used for locomotion, allowing cells to move through aqueous environments.
For example, sperm cells use flagella for swimming towards the egg during fertilization. While flagella are essential for the movement of certain cells, they are not typically involved in the conventional cell migration process observed in tissues.
Cell migration usually involves cells within a three-dimensional tissue moving by protruding, attaching, and pulling themselves along the extracellular matrix rather than moving freely through a fluid.

Actin

Actin is a highly abundant protein within cells, forming microfilaments that constitute a significant part of the cytoskeleton. It is essential for various cellular functions, including maintaining cell shape, enabling cellular motion (such as cell migration), and division.
In cell migration, actin filaments undergo rapid polymerization and depolymerization at the leading edge of the cell. This process creates protrusions called lamellipodia and filopodia, which attach to the substrate, allowing the cell to pull itself forward.
The dynamic remodeling of actin filaments is critical for cell motility, making actin one of the key players in cell migration.

Centrioles

Centrioles are cylindrical structures located near the cell nucleus in the centrosome. They play an essential role in cell division by helping to organize the microtubule spindle apparatus, which separates chromosomes during mitosis.
Additionally, centrioles are involved in the formation of cilia and flagella, but they do not directly contribute to cell migration. Rather, their primary functions are related to organizing microtubules and ensuring the correct progression of cell division cycles.
Given their specific roles, centrioles are critical for cell division but are not active participants in the process of cell migration.