Microtubules are absent in Mitochondria.

The correct answer is option 'A' because microtubules are not found in mitochondria. Microtubules are structural components of eukaryotic cells that are composed of tubulin proteins. They play a crucial role in various cellular processes such as cell division, cell movement, and intracellular transport. However, mitochondria do not possess microtubules.

Mitochondria are membrane-bound organelles found in most eukaryotic cells. They are often referred to as the "powerhouses" of the cell due to their role in producing energy. Mitochondria have a double membrane structure and contain their own DNA and ribosomes. They are involved in cellular respiration and generate ATP, which is the main source of energy for the cell.

Microtubules, on the other hand, are hollow cylindrical structures made up of tubulin protein subunits. They provide structural support to the cell and are involved in maintaining cell shape and integrity. They also form the mitotic spindle during cell division, which is essential for the accurate separation of chromosomes.

Microtubules are found in various parts of the cell, including the cytoplasm, cilia, flagella, and centrioles. They are responsible for the movement of organelles and vesicles within the cell and also play a crucial role in flagellar and ciliary movement. In the case of flagella, microtubules form the axoneme, which is the structural core responsible for flagellar movement.

However, mitochondria do not possess microtubules. They have their own specialized systems for intracellular transport and movement. Mitochondria are able to move within the cell by using molecular motors, such as kinesin and dynein, which transport them along the cytoskeleton. These molecular motors interact with microtubules, but the microtubules themselves are not present within the mitochondria.

In summary, microtubules are absent in mitochondria. While microtubules are important for various cellular processes and are found in structures such as flagella and centrioles, they are not present within mitochondria.

Mitochondria
Microtubules are absent in mitochondria. Mitochondria are membrane-bound organelles found in most eukaryotic cells. They are often referred to as the "powerhouses" of the cell because they are responsible for generating most of the cell's energy in the form of ATP (adenosine triphosphate).

Microtubules
Microtubules are hollow, cylindrical structures made up of tubulin proteins. They play a crucial role in various cellular processes, including cell division, cell shape maintenance, intracellular transport, and organelle positioning. Microtubules form the structural framework of the cell, providing stability and support.

Flagella
Flagella are whip-like structures that protrude from the surface of certain cells. They are responsible for cell motility and movement. Flagella consist of a bundle of microtubules surrounded by a membrane. The microtubules in the flagella provide the structural support and allow for movement by sliding past each other.

Spindle Fibres
Spindle fibers are a type of microtubule that play a critical role in cell division. During mitosis and meiosis, spindle fibers help separate the chromosomes into two daughter cells. They attach to the chromosomes and pull them apart to ensure that each daughter cell receives the correct number of chromosomes.

Centriole
Centrioles are cylindrical structures found in animal cells, usually located near the nucleus. They are involved in the organization of microtubules and play a crucial role in cell division. Centrioles are made up of nine triplets of microtubules arranged in a specific pattern.

Explanation
Microtubules are absent in mitochondria. Unlike other organelles such as flagella, spindle fibers, and centrioles, mitochondria do not possess microtubules. Instead, they have their own unique structural organization. Mitochondria have an inner and outer membrane, with the inner membrane being highly folded to form cristae. These cristae provide a large surface area for ATP synthesis. While microtubules are essential for various cellular processes, they are not present in mitochondria.

In conclusion, microtubules are absent in mitochondria. They are, however, present in other cellular structures such as flagella, spindle fibers, and centrioles, where they play crucial roles in cell motility, cell division, and intracellular transport.