The cell is the smallest unit of life that formed life. The human body is consists of trillion cells. They provide structure for the body, absorb nutrients from food, convert those nutrients into energy, and do specialized functions. So, if you wonder why do cells divide, continue reading this text.
But before we go to the topic of cell division, let me further give you an overview of cells. What are they made of and what are their individual function.
Major Parts of the Human Cells
Cells have many parts, with individual special functions. Organelles are a number of these parts that are specialized structures that perform individual tasks in the cell. The human cells contain the following major parts.
- Cytoplasm – is the material outside of the nucleus.
- Cytoskeleton – is a dynamic network of interlinking protein filaments present in the cytoplasm.
- Endoplasmic reticulum (ER) – plays an important function in the organic process.
- Golgi apparatus – packages proteins into vesicles before secretion. Thus, plays a key role within the secretory pathway.
- Lysosomes and peroxisomes – contain enzymes that break down fatty acids and amino acids.
- Mitochondria – the powerhouse of all cells
- Nucleus – contains the genetic material (DNA) of eukaryotic organisms.
- Plasma membrane – is found in all cells that separate the interior of the cell from the outside environment.
- Ribosomes – functions to synthesize proteins that are needed for many cellular functions.
Cell Division – Why Cells Divide?
To understand why cells divide, one must know what cell division is. Cell division is the process where a single cell, generally called the parent cell, divides into two daughter cells called mitosis.
Five Stages of Cell Division:
- Prophase: The mitotic spindle forms and the chromatin condense, exposing the chromosomes. This is the longest phase of cell division.
- Prometaphase: This is the mitotic phase following prophase and preceding metaphase.
- Metaphase: The chromosomes align in a plane across the mid cell of the mitotic spindle.
- Anaphase: Stage when sister chromatids separate and daughter chromosomes move towards opposite spindle poles.
- Telophase: This is the 5th and last stage of mitosis. It is when daughter chromosomes reach and poles. New nuclei envelop forms around each of them.
3 Major Reasons Why Cells Divide :
1. Cell Reproduction
Binary fission occurs in organisms that undergo asexual reproduction. It produces an organism called bacteria which duplicates their genetic material and divides it into two parts.
Each part has a copy of the genetic material that repeats this process. It then multiplies into a colony of organisms that resemble each other genetically.
Cell reproduction is the process where human reproduction is based as well as the basis for the generation of life in other classes of organisms.
2. Cell Growth happen when cells divide
Cell division helps organisms grow by either increasing cell number or their size. It grows continuously dividing to increase the size of the organism.
Until the cell reaches adulthood, they grow as the cells divide. At the stage of adulthood, nerve cells and heart cells can no longer have the ability to divide.
3. Cell Repair
Growth factors that are present in the extracellular matrix stimulate tissue repair. It contains materials such as water, minerals, and compounds to help in the repair. If the injury is minor, the tissue has the ability to regenerate itself through mitosis. However, with serious injuries, regeneration does not occur and scarring occurs.
Factors That Influence Cells to Divide
Cell division does not occur continuously. This happens in a controlled way when required. Internal and external factors exist that regulate when cells divide.
1. Internal Factors
During the interphase stage, internal factors determine if cell division should take place or not.
For mitosis to occur, internal factors present can stop the division process before it begins. It can also stop the cells from further dividing when the process has already started.
Governed by internal and external factors, checkpoints exist in each stage of cell division. These internal factors regulate when cells need to divide and when they don’t.
Main internal factors during checkpoints :
- Checks if cells have enough materials on hand. These materials should be properly divided into two functional daughter cells. Otherwise, cell division will be halted.
- The DNA would have to break down into two daughter cells. Each must also contain an equal amount of DNA and should not be damaged.
2. External Factors
External factors affect internal factors. The process may or may not continue until problems are repaired. Some external factors that influence internal factors are:
- Toxins – damaged cell DNA caused by toxins prevents cell division from taking place.
- Viruses – it replicates by hijacking a cell during division. It can also attack the DNA of cells. If recognized at a checkpoint, cell division will not take place.
- Drugs – cancer drugs block internal factors that regulate the process of cell division. The cell division process cannot go on when blocked.
- Radiation – change DNA molecules, affecting their genetic sequences. Cells either repair the DNA, or stop the division, or the cell could die.
- Raw materials – cells won’t grow enough for the division to start if nutrients required for cell division are not available.
Conclusion:
- The cell is the smallest unit of life that formed life.
- Cells divide for the basic functionality of life to happen. It aids reproduction, growth, and repair.
- In normal cell division, parent cells divide into their daughter cells during mitosis.
- Then it moves into the interphase stage that would determine if the cycle would continue or not.
- Normal cell division helps for the replacement of dead cells in living organisms.
- The cells of little babies continue to divide rapidly to aid growth. This rapid cell division would stop as the child goes into adulthood.
- The effects of errors of mitosis on living organisms can range from being unharmful to being deadly. It will depend on the magnitude of the errors. Cancer is an example of the result of errors in cell division.
Isn’t it interesting to know how this smallest unit of life is critical to the cycle of life? They need to undergo a process to determine if they can continue growing or not.
Another interesting topic that tells life forms and survival is about the bees. Read it from my previous post here.
