The different types of human chromosomes that exist
The types of human chromosomes that exist
The first thing is that human chromosomes can be classified in various ways based on different criteria. For example, there are different chromosomes based on their shape, function, or centromere position. Remember that chromosomes are essential for storing and packaging genetic information in the form of DNA.
When a birth defect needs to be checked, anomaly , genetic mutation or genetic malformation, these details can have a significant impact. Therefore, it's important to make this distinction first…
1. Chromosomes according to their shape
The shape that can be perceived through a microscope allows us to classify chromosomes using two criteria:
- Linear chromosomes . This type of chromosome is arranged in elongated, linear strands of DNA aligned in pairs. The chromosomes of eukaryotic cells are often of this type, and they are found not only in humans but also in plants and animal species.
- Circular chromosomes . Circular chromosomes have only one circular DNA molecule, complemented by other proteins. This chromosome shape is common in bacteria, for example.
A linear chromosome, therefore, implies greater DNA complexity. Hence, they are often found in different proportions depending on the location. We can point out that a linear chromosome presupposes a higher level of evolution in an organism, whereas a circular chromosome is so because it doesn't need to evolve.
2. Chromosomes according to functionality
When a human being reproduces sexually, there are two types of chromosomes: somatic and sex. Both are of crucial importance, although they address different aspects. These are the main characteristics of each:
- Somatic or autosomal chromosomes. Somatic or autosomal chromosomes do not indicate a person's sex. However, they do provide genetic information about other traits, such as skin, hair, or eye color, to name a few. These are the pairs of chromosomes 1 to 22. They therefore transmit a large part of the genetic background of their offspring.
- Sex chromosomes. A sex chromosome does determine the sex of the person or species, male or female. Specifically, this can be determined by the 23rd chromosome pair. This is their main function: gender assignment. Women have a pair of X chromosomes, while men have one X and one Y chromosome.
Let us remember that beings humans have 23 pairs of chromosomes . The first 22 pairs are somatic, while the 23rd pair is sexual. For this reason, the function of these chromosomes in humans, but also in other animal and plant species, is crucial.
3. Chromosomes according to the position of the centromere
The centromere position It is also crucial when classifying chromosomes. Not surprisingly, it is the narrowest and most concentrated area of the chromosome. These are the types:
- Acrocentric chromosome. Acrocentric chromosomes are those with one telomere closer together than the other. The practical consequence is that their shape is irregular, since one arm is much longer than the other. This asymmetrical shape makes them easily distinguishable when examined.
- Metacentric chromosome. A metacentric chromosome is notable for its symmetry. The reason? The centromere is right in the center of the chromosome, and this results in its arms being the same length. We are, therefore, looking at a symmetrical chromosome.
- Submetacentric chromosome. When we talk about submetacentric chromosomes, we refer to those that, although they have the centromere near the center, are slightly tilted to one side. In this case, they are chromosomes with a more symmetrical shape than others.
- Telocentric chromosome. Finally, we must mention telocentric chromosomes, those that have a centromere at one end. This is precisely why they have only one very long arm and another extremely short, almost imperceptible arm.
Knowing all this information is extremely important when it comes to correctly differentiating chromosomes. Not surprisingly, it's a first way to distinguish them and, from there, draw conclusions.
What is the use of knowing the different types of chromosomes?
There are several reasons why it's important to understand the different types of chromosomes we have. We highlight these practical, therapeutic, and other applications:
Diagnose and treat genetic diseases
The first useful element of knowing about chromosomes is that it is much easier Diagnose genetic diseases . It's true that having information from the parents will make it even easier. In some cases, there are mutations that already indicate this possible problem.
And, with the diagnosis, also comes the possible treatment . It should also be noted that the earlier the diagnosis, the better when it comes to taking measures to reverse complicated situations.
Prenatal diagnosis
Another advantage of knowing the human chromosomes is that you can do Prenatal genetic testing . This is especially useful in conditions such as Down syndrome, where there is a duplication of chromosome pairs. Although it is a more expensive technique, it can be performed during pregnancy.
Check for the possibility of genetic alterations
The possibilities or probabilities of genetic alterations are more easily verified if you know the chromosomes. For example, it is possible to perform a genetic compatibility test This allows you to address these issues. And, undoubtedly, if you know the likelihood of mutations in your offspring, you can decide on your family planning.
To better understand the evolution of species
Finally, understanding human chromosomes sheds light on the story of human evolution. Therefore, from a scientific research perspective, it is extremely useful for correctly identifying organisms. In turn, establishing chromosome relationships with other species opens up a field for improving therapeutic treatments.
In summary…
Understanding human chromosomes allows us to learn more about traits, but also about possible genetic diseases. Do you want to take a genetic test with guarantees? Genotics You'll find different options, classified by type, price, and shipping. Learn more!