If you are someone who was a slight idea about genetics and DNA, you must know that it is nowhere as simple as it sounds. You must have also read the term spindle fiber. It is known that animal cells have spindle fibers, but what about plant cells? Do plant cells have spindle fibers?
The plants do have spindle fibers and we have written a comprehensive answer to your question, as well as all the important things you must know about spindle fibers in plant cells. So, without further ado, let us jump into the main topic!
What are Spindle Fibers?
In simple terms, spindle fibers are made of proteins, and it is responsible for keeping the genetic content of the cell separate. When an organism grows, cell division takes place. Spindle fibers are formed during mitosis, a type of cell division where one mother cell divides and produces two identical daughter cells.
Microtubules are present in this protein structure, and it is made by the centrioles of the cell. Initially, microtubules are referred to as filaments, but after cell division starts, they are called microtubules.
Centrioles are structures that look like a pair of wheels, and they are found in the part of the cell, which is known as the centromere area. In animals the centrioles are present, so they organize the microtubules in their spindle fibers.
However, plants do not have centrioles, so how are the microtubules organized in the spindle fiber? Let’s address a common misconception now. Since plant cells do not have centrioles a lot automatically assume that they also don’t have spindle fibers.
There is a part of the cell called the centromere. This area in plant cells is responsible for organizing microtubules properly in the protein structure we are discussing. The centromere is located around the nuclear envelope, and it has centrosomes that help in making the spindle fibers.
Are there Spindle Fibers in Plant Cells?
If you have gone through the last section, you should already know that plant cells have spindle fibers. As we have mentioned the centrosomes make the spindle fibers in a plant cell. Somatic cells in plants undergo mitosis, and spindle fibers are made when mitosis occurs. To be more precise, mitosis begins in the nucleus of somatic cells.
There are 6 main stages of mitosis in plant cells. These stages are:
- Preprophase
- Prophase
- Prometaphase
- Metaphase
- Anaphase
- Telophase
If you look at diagrams comparing mitosis of plant cells and animal cells, you will see that they are, in fact, quite similar. There is just an extra stage in plant cell mitosis, which is the preprophase before the prophase.
In the preprophase, the centrosomes start organizing the microtubules, so the spindle fibers start to form. However, they are not visible till the prophase. The centrosomes move to opposite sides, so spindle poles are created.
During the prometaphase, you will see that from the two spindle poles, long filaments made of protein (the microtubules) will begin to come out.
What does it do in Plant Cells?
When the microtubules, also known as kinetochore microtubules, appear in the prometaphase, they start to latch onto the chromosomes’ kinetochores.
Now let’s look at what the spindle fibers do in the metaphase. In this phase, more chromosomes get attached to the microtubules, so it gets denser, and the chromosomes start to get aligned properly in the metaphase plate. This continues to the telophase as well till the two daughter nuclei are created entirely.
After the two daughter nuclei are formed, the spindle fibers start to break down as the cell divides to form two new daughter cells.
Is it Important?
Although the spindle fiber is not a very large structure, it does have a very important job and is present in both plant and animal cell structures. It ensures that all the chromosomes are equally separated from the daughter cells. Without the spindle fiber, the two daughter cells would not have each of the same chromosomes. Actually, without the formation of these protein structures, mitosis would not have been possible at all!
Final Words
Learning about cell structures and organelles can get intimidating very quickly because of all the technical terms involved. However, if you take your time to understand every term, we can assure you that you will be able to grasp everything we’ve said here.
We hope you still don’t think that plants don’t have spindle fibers because they don’t have centrioles; they have centrosomes to save the day!
Related Posts:
How Does A Cell Wall Protect A Plant Cell | A Barrier Against External Threats
Do Plant Cells Have Cell Walls? Functions & Importance
Do Plant Cells Have Chromosomes? Find Out Everything Here
From Water to Sunlight: The Raw Materials for Photosynthesis
What Is Plant Embryo? Everything You Need to Know