Mudalovers, what do you remember about chromosomes? Yup, one of the materials in Biology lessons at school teaches us about how traits, characteristics and diseases are passed from parents to children. You also remember that the chromosomes in our bodies are in pairs, aka diploid, with a total of 46 or 23 pairs. Are there unpaired chromosomes in our body?
Of course there is, it’s just that if we have unpaired chromosomes, it means there is an abnormality in our body. Because this chromosomal abnormality can impact the function and appearance of the body, you know, Mudalovers.
For example, an abnormal physical appearance, health problems, the body not being able to function as it should, mental disabilities, even death. So, why can chromosomes come in pairs or what is known as diploid? Let’s discuss it together.
Overview of Chromosomes
Talking about diploid cells cannot be separated from discussing the chromosomes themselves. By knowing what chromosomes are, you can more easily understand diploid cells. So what is meant by chromosomes?
In short, chromosomes are a collection of DNA molecules in which all the genetic material of an organism is contained. Simply put, chromosomes are the same as a collection of information that creates a living creature. Humans, for example, have 46 chromosomes or 23 pairs consisting of 22 pairs of autosomes or body chromosomes and the other one is gonosomes or sex chromosomes. Sex chromosomes are further divided into two types, namely X and Y chromosomes.
The combination of the X and Y chromosomes plays a role in determining a person’s gender. For example, if the chromosomes are XY, then it is male, if XX then it is female. The important thing you need to remember about chromosomes is that the number of chromosomes does not determine the quality of a living creature.
Every living creature has a different number of chromosomes, some have less than ten, some have up to thousands. For example, dogs have 78 chromosomes, while chimpanzees have 48. From this number of chromosomes, can we determine whether these two living things are good or bad? Not at all. Because chromosomes will not be better or worse based only on their number or size.
Like a book, a larger number of chromosomes is the same as a book that has many series. Books with more series do not mean they have more or better information than those with fewer series. For example, Tere Liye’s Bumi series which consists of 13 books does not automatically contain more and better information than Dee Lestari’s Supernova series with 6 books.
If you want, you can even think of chromosomes as the number of words in the two book series. Suppose the 13 books in the Earth series have a word count of 1.3 million words while Supernova has 600 thousand words.
Can you judge which one is funnier, more enjoyable, or of better quality from the number of words? No, right? Because each book in each series has different content, so do living creatures.
What is Diploid?
To answer the question above, we will start from the beginning, namely the meaning. So for those of you who don’t know, diploid is a cell that has two complete sets of chromosomes (2n). These two sets of chromosomes come from the parents, one from the father and one from the mother.
Apart from diploids, there are also cells that only have one or half the number of chromosomes of their parent (n). Thus, in this world there are two types of living creatures when viewed from the number of chromosomes in their bodies, namely living creatures with diploid chromosomes and those with haploid chromosomes.
We have 46 diploid chromosomes, aka 23 pairs. This means that if we break it down, in our bodies there are 23 chromosomes from the mother and 23 chromosomes from the father. Apart from that, there are also haploid chromosomes, totaling 23 chromosomes. Haploid chromosomes are found in egg cells (for women) and sperm cells (for men). Therefore, when egg cells and sperm cells unite, they will form a new human who has 46 chromosomes in their body.
Animals are the same as humans, because almost all types of animal cells are diploid. Likewise, all organisms that produce sexually, all have two copies of chromosomes with different origins, namely the father and the mother. That way, all organisms can produce better offspring.
In this world there are also several species that have haplodiploid cells. Usually in this species, males have haploid cells while females have diploid cells.
Read Also : What is a Taproot? Definition, Characteristics, Functions and Examples of Plants
Diploid Example
If you are asked to name examples of diploid cells, don’t panic because all somatic cells in the human and animal body are diploid cells. This means you can name any cell as an example. Because cells are diploid, genetic diversity can occur. Some examples of diploid cells in the human body are muscle cells, skin cells, blood cells, nerve cells, or bone cells. The only cells in the human body that are haploid, meaning they contain only one set of chromosomes, are gametes or sex cells.
Why is there only one set of sex cells for men and women? The goal is that when the reproductive process occurs, the sperm cells and egg cells can fuse to form a diploid cell, also known as a zygote.
Thus, the diploid cells of this zygote can contain genetic information from the hypoloid cells of the father and mother, 50% from the sperm cells and 50% from the cells of the mother. Just imagine if there were two sets of sex cells? The result of the union of diploid sperm cells and egg cells will become diploid cells containing 46 pairs of chromosomes or 92 hiploid cells.
Diploid Number
The diploid number which is usually written as “2n” is the number of chromosomes in the cell nucleus. The human body has 23 pairs of chromosomes so the human diploid cell number is 2n = 46.
Two of the chromosomes in human cells are the chromosomes that determine sex. Women have two X chromosomes which are written as “XX”, while men have one X chromosome and one Y chromosome so they are written as “XY”. These chromosomes were previously referred to as haploid because they only contain one set of chromosomes.
Talking about diploid cell numbers, you need to remember that the number “2n” for each organism is different. For example, like a dog, there are 28 chromosome cells so 2n = 28 which consists of 14 pairs of chromosomes. Meanwhile for elephants, 2n = 56 or 28 pairs of chromosomes.
Diploid Cell Reproduction
Diploid cells in the body can reproduce by the process of mitosis. When this process occurs, the cell will make an identical copy of itself and imitate the DNA which is then distributed evenly between its two daughter cells.
Diploid cells reproduce by the process of mitosis. In mitosis, a cell makes an identical copy of itself allowing the DNA to be replicated resulting in an identical copy of itself.
Somatic cells are produced through this cycle, while gametes from the meiosis cycle. In the meiosis cycle, this “reproduction” process produces four daughter cells instead of two and contains half the number of chromosomes.
Diploid and Haploid Life Cycles
All sexually reproducing organisms, such as humans, have a predominantly diploid life cycle and spend most of their lives as diploid adults. Therefore, almost all cells in the body of this type of organism are diploid, except for sex cells (gametes).
When they reach the sexual maturity phase, organisms with diploid cells will produce sex cells (haploid) through the process of meiosis. Then when fertilization occurs, the two sex cells (haploid) fuse and form a diploid zygote. After that, this diploid zygote will reproduce using the mitotic cycle to produce two daughter cells that are identical to itself. This reproductive process continues to be repeated until the diploid zygote becomes a diploid adult. This is the life cycle of diploid and haploid cells.
What about plants and animals? Most plants and animals consist of diploid cells. Multicellular animals usually have diploid cells throughout their lives. Meanwhile, in multicellular plants, the cell life cycle oscillates between the diploid stage and the haploid stage. This tossing process is known as alternation of generations or a type of life cycle that commonly occurs in vascular plants and non-vascular plants.
Meanwhile, for liverworts and mosses, the main phase of their life cycle is the haploid phase. Then, in flowering plants and gymnosperms, the diploid phase becomes the primary phase. Meanwhile, the survival rate of the haploid phase will be influenced by the diploid generation.
Other organisms, such as algae and fungi, usually spend most of their life cycle as haploid organisms that reproduce through spores.
Read Also : What is Protein? Definition, Function, Types and Examples of Food
Difference between Haploid and Diploid Cells
In the explanation above, it is stated that there are two types of cells, namely haploid and diploid. Each has its own characteristics, but the main difference between these two cells is the number of sets of chromosomes in their nuclei.
In biology, there is a term used to determine the number of sets of chromosomes in a cell nucleus, namely pliody. Where each type of organism has a different number of chromosomes. Eukaryotic organisms, for example, have two types of cells, namely diploid cells and haploid cells.
So what is the difference between haploid cells and diploid cells besides the number of chromosomes in the nucleus? Actually, if you want, you can find the characteristics of each cell in the explanation above. However, especially for those of you who are still confused, here is a brief summary that can help you understand these differences.
Sel haploid
Haploid cells are cells that contain only one complete set of chromosomes. One example of a haploid cell that is often mentioned is sex cells (gametes). Haploid cells originate from the meiosis cycle and they play an important role in the process of sexual reproduction.
When the haploid cells from the father and mother combine, the offspring will have two complete sets of chromosomes which are called diploid cells. A haploid cell has a number of chromosomes in the nucleus that create one set. As humans, for example, have 23 chromosomes, which means 46 diploid cells.
Some people still think that haploid cells and monoploid cells are the same type of cell. In fact, the two have a main difference, namely that haploid cells only have one complete set of chromosomes while monoploid cells have a unique number of chromosomes in biological cells.
In diploid organisms, usually diploid cells consist of complete chromosomes while haploids only have half the number of chromosomes in the cell nucleus. Some organisms, such as algae, have a life cycle that causes the cells in their bodies to become haploid. Apart from that, there are also several organisms, one example of which is the male ant which actually lives as a haploid organism throughout its life.
This is different from humans and many other organisms which only have haploid cells in the sex cells.
Diploid Cells
Diploid cells are cells that have two sets of chromosomes, each of which comes from their parents. So one set of chromosomes comes from the father and another set of chromosomes comes from the mother.
In diploid organisms, these two sets of chromosomes will create two sets of offspring. What a waste of diploid organisms on this earth? The majority of mammals are diploid organisms that have two copies of each chromosome in their cells, including humans.
Diploid cells carry out the reproductive process through the mitotic cycle. This process will later create a very identical copy of the parent cell. In humans, all somatic cells are diploid cells including cells that form muscles, bones, hair, skin and other body parts except egg cells or sperm cells.
Comparison table of diploid cells and haploid cells
| Diploid | Haploid | |
| Understanding | Cells containing two complete sets of chromosomes (2n) | Cells that have one set of chromosomes (n) |
| Cell division and growth | Reproduction uses the mitotic cycle to produce daughter cells that are identical to the parent cell | The result of the meiosis cycle or diploid cell division which gives rise to haploid germ cells. Haploid cells will fuse with other haploid cells in the fertilization process. |
| Example | Blood cells, skin cells, muscle cells | The cells used in the process of sexual reproduction are egg cells and sperm cells (gametes) |
Read Also : What Are Stem Cuttings? Definition and Examples
Conclusion
From the explanation above, it turns out that chromosomes are paired because each parent, namely father and mother, contributes one 23 chromosome. So ideally every creature that reproduces sexually will have paired chromosomes.
However, this does not mean that all living creatures are free from abnormalities in the number of chromosomes. Humans, for example, can have less or more than 46 chromosomes which is caused by the meiosis cycle being disrupted when the egg and sperm cells fuse.
This chromosomal disorder has quite varied impacts, the most severe of which can even cause fetal death before birth. Apart from that, there are also those that cause developmental disorders at birth.
One of the most well-known chromosomal disorders is Down’s Syndrome. Down’s Syndrome itself is a chromosomal abnormality that has trisomy 21. Trisomy itself is an excess of one chromosome (X or Y), so what should be 2 chromosomes 21, becomes 3.
Then there is also a chromosomal disorder called monosomy. This is a disorder where a living creature is missing 1 chromosome. For example, Turner Syndrome, which is a condition where one of the sex chromosomes is missing. While a human should have XY or XX chromosomes, in Turner Syndrome sufferers, the sex chromosomes are actually XO or even just X.
That’s the discussion about diploids and also examples. Hopefully all the discussion above is useful for you. If you want to look for articles about genetics, you can get them at Mudabicara.com.
To support Mudalovers in broadening their knowledge, Mudabicara always provides quality articles so that Mudalovers has useful information.