What is genetic inheritance and why is it important?

What is genetic inheritance?

Geneticinheritance refers to thetransmission of physical, biological, physiological and personality traits through genes(1) from parents to children, thanks to the intervention ofgenetic factors. These characteristics are contained in the genetic material of deoxyribonucleic acid also called DNA. (2)

In this sense, during the crossing of the human species thecharacteristics of the parents contained in the chromosomes(3) are transmitted to the offspring with dominant traits and recessive traits.

By this same mechanism, different diseases are transmitted or inheritedif any gene of the ancestors contains some type of genetic mutation.

Note: All living species differ genetically, because the number of chromosomes they contain in their genetic material is not equal, expressed in their genotype and phenotype.

What is the importance of genetic inheritance?

Here are some of themost outstanding characteristicsof genetic inheritance, which give it great importance in humans:

1. It is key to the existence of life

Genetic inheritance allows animal species and the human species to to exist throughout history, even giving them the Ability to adapt to changes that are occurring in the environment that allow their perpetuity.

To highlight: Human beings and animal species progressively adapt to changes in the environment , transmitting this information to their genes and from there to their offspring, guaranteeing the existence of the species .

2. Allow evolution

As we mentioned before, the adaptability of the human being and of the species in general to the continuous changes that occur in the environment, is conserved in the genes so that they can be acquired by the new generations, in such a way that they guarantee the continuous evolution of the species. .

3. It gives meaning to reproduction

Without inheritance, reproduction does not make much sense, because life as we know it would be submerged in a vacuum, since it could not develop in complexity and diversification, aspiring only to repeat itself without being able to transmit to new descendants, the genetic memory of the species with the traits that identify it.

What are the types of genetic inheritance?

Thanks to scientific studies and advances in the field of genetics , we can currently talk about the following types of genetic inheritance:

1. Autosomal inheritance

Autosomal inheritance (4) is one of the forms of genetic inheritance, in which traits or defects pass from parents to children, that is, they are inherited.

In this type of inheritance, 22 genes from the father join 22 genes from the mother, where the genetic material of both is transmitted to the offspring. Pair 23 is not an autosome chromosome because it is sex-linked.

You should know: At this point there are two types of autosomal inheritance : Autosomal dominant inheritance and autosomal recessive inheritance.

2. Sex-linked inheritance

Sex-linked inheritance refers to the process by which offspring acquire sex. In this sense, the father contains Two “xy” chromosomes in pair 23 and the mother contains two “xx” pairs

This pair 23 is linked to the sexuality of the offspring and sex is defined at the time of fertilization, being determined by the type of sex chromosome carried by the sperm (x or y) at the time of fertilizing the ovum (x).

Note: Females have Two “X” chromosomes, so they will have two copies of each “x”-linked gene. The sex-related diseaseis much more common in men since they have a single copy of the “x” chromosome that carries the mutation.

3. Dominant inheritance

Dominant inheritance (5) in humans refers to the fact that the traits that predominate in the offspring are transmitted by those alleles that have more strength to express themselves phenotypically.

For this to occur, during hereditary transmission, a dominant gene of the pair must always be present, so that it is expressed in the phenotype, for example, skin color, eyes, hair type, among others.

4. Recessive inheritance

Recessive inheritance (6) refers to the manifestation of weak traits in the offspring and they are transmitted only by the alleles that contain weak traits.

You should know: For this to happen, the two alleles that make up the pair within thegene must be recessive.

5. Codominant inheritance

In the case of codominant inheritance (7) , the two dominant genes are expressed at the same time in the phenotype of the offspring and this happens because in both the father and the mother, the information from both genes behaves as dominant.

Note: The particularity in codominant inheritance is that both traits are manifested separately in the phenotype , that is, without mixing.

6. Intermediate inheritance

In intermediate inheritance, as in codominant inheritance , both the allele of the father and the mother are dominant, but with the difference that neither of them is shown as it originally is in the phenotype of the offspring.

To highlight: In this case , an intermediate phenotype is expressed and corresponds to one of the inheritances that are outside the laws of Gregor Mendel. (8)

Key Findings

• Genetic inheritance consists of the transmission of physical, biological, physiological and personality traits through genes.
• The characteristics of genetic inheritance are contained in the DNA of cells.
• Genetic inheritance allows the existence and evolution of species.
• Genetic inheritance gives meaning to the reproductive fact of animal and plant species, allowing their development and diversification.