WHAT DOES GENETICS STUDY? - BIOLOGY - 2025

The genetic studies heredity from a scientific point of view. Genetics is inherent in human beings and other living organisms, in this way, this science can be divided into numerous categories that vary according to the type of species studied. This is how there is a genetics of human beings, another of plants, another of fruits, and so on.

Heredity is a biological process in which parents pass certain genes on to their children or offspring. Each member of the offspring inherits genes from both biological parents, and these genes manifest in specific characteristics.

Some of these characteristics can be physical (for example, the color of hair, eyes and skin), on the other hand, some genes can also carry the risk of carrying certain diseases such as cancer and disorders that can be passed from parents to their offspring.

The study of genetics can be divided into three fundamental and interdisciplinary fields: gene transmission, molecular genetics, and population genetics. The first type is known as classical genetics, as it studies the way genes are passed from one generation to another.

Molecular genetics, on the other hand, focuses on the chemical composition of genes and how this composition varies from one species to another and over time. Finally, population genetics explores the composition of genes within specific population groups (Knoji, 2017).

Fields of Study of Genetics

The study of genetics today comprises a large number of fields that can be related to each other. These include the following:

• Classical or formal genetics: studies the individual transmission of genes between families and analyzes more complex forms of inheritance.

• Clinical genetics: it is the diagnosis, prognosis and in some cases, the treatment of genetic diseases.

• Genetic counseling: it is an important area of ​​clinical genetics that involves diagnosis, calculation and interpersonal communication to treat some genetic diseases.

• Cancer genetics: it is the study of hereditary genetic factors and sporadic cancer (MedicineNet, 2013).

• Cytogenetics: is the study of chromosomes in health and disease.

• Biochemical Genetics: is the study of the biochemistry of nucleic acids and proteins, including enzymes.

• Pharmaco-genetics: it is the way genes govern the absorption, metabolism and disposition of drugs and their unpleasant reaction to them.

• Molecular Genetics: is the molecular study of genetics, particularly including DNA and RNA.

• Immunogenetics: is the study of genetics related to the immune system, including blood groups and immunoglobulin.

• Behavioral genetics: is the study of genetic factors that affect behavior, including mental illnesses and conditions such as retardation.

• Population genetics: it is the study of genes within groups of populations, including genetic frequency, alleles present only in a group of individuals, and evolution (Hedrick, 2011).

• Reproductive genetics: includes the study of genes and chromosomes in gestational cells and embryos.

• Developmental genetics: studies normal or abnormal development in humans, including malformations (birth defects) and hereditary factors.

• Ecogenetics: study of genes and their interaction with the environment.

• Forensic genetics: it is the application of genetic knowledge, including DNA codes, to legal matters (Biology-Online, 2016).

DNA

Genes in the cell

Genetic information is encoded in the nucleus of the cells of all living organisms.

Genetic information can be considered as the record of information from the parents that is stored in a record book to be later delivered to their offspring (Mandal, 2013).

Chromosomes

Genes depend on chromosomes. Each organism has a different number of chromosomes. In humans, we have 23 pairs of these small cord-like structures that inhabit the nucleus of all cells.

It is said that there are 23 pairs of chromosomes, since in total they make up a group of 46 units, where 23 come from the father and 23 from the mother.

Chromosomes contain genes like a book contains information on its pages. Some chromosomes may contain thousands of important genes, while others may contain only a few.

Chromosomes, and therefore genes, are made of a chemical known as DNA or deoxyribonucleic acid. Chromosomes are long lines of tightly knit DNA strands (Hartl & Ruvolo, 2011).

At one place in its length, each chromosome has a construction point, called the centromere. The centromere divides the chromosomes into two arms: one arm is long and the other is short.

Chromosomes are numbered from 1 to 22 and those that are common to both sexes are known as autosomes.

Also, there are chromosomes to which the letters X and Y are assigned to differentiate the sex of the individual who carries them. X chromosomes are larger than Y chromosomes.

Chemical bases

Genes are made up of unique chemical-based codes that comprise substances A, T, C, and G (Adenine, Thymine, Cytosine, and Guanine). These chemical bases form the combinations and permutations between chromosomes.

Metaphorically speaking, these bases are like the words in a book, operating as independent units that make up the entire text.

These chemical bases are part of DNA. As in a book, when words are put together, the text has a meaning, the DNA bases work in the same way, telling the body when and how it should grow, mature and carry out certain functions.

Over the years, genes can be affected and many of them can develop failure and damage due to environmental factors and endogenous toxins (Claybourne, 2006).

Male and Female

Women have 46 chromosomes (44 autosomes and two copies of the X chromosome) encoded in the cells of their bodies. In this way, they carry half of these chromosomes within their eggs.

Men also have 46 chromosomes (44 autosomes, an X chromosome, and a Y chromosome) encoded in every cell in their bodies.

In this way, they carry 22 autosomes and an X or Y chromosome inside their sperm cells.

When a woman's ovum unites with a sperm, they result in the gestation of a 46-chromosome baby (with a mixture of XX if it is a woman or XY if it is a man).

Genes

Each gene is a piece of genetic information. All DNA in cells is part of the human genome. There are approximately 20,000 genes on one of the 23 pairs of chromosomes found in the nucleus of cells.

To date, 12,800 genes have been traced to specific locations on each chromosome. This database began to be developed as part of the Human Genome Project.

This project was officially concluded in April 2003, without yielding a conclusive number of chromosomes in the human genome.

References

1. Biology-Online. (January 17, 2016). Biology Online. Obtained from Genetics: biology-online.org.
2. Claybourne, A. (2006). Portman Mansions: Evans.
3. Hartl, DL, & Ruvolo,. (2011). Burlington: Headquarters.
4. Hedrick, PW (2011). Genetics of Populations. Sudbury: John and Bartlett Publishers.
5. (2017). Knoji. Obtained from Three Major Fields of Genetics: genetics.knoji.com.
6. Mandal, A. (March 18, 2013). News Medical. Retrieved from What is Genetics ?: news-medical.net.
7. (March 13, 2013). MedicineNet, Inc. Retrieved from Medical Definition of Genetics: medicinenet.com.