The process by which genetically controlled characteristics pass from parents to offspring.
All of the qualities and characteristics which are passed down from parents.
Acquisition of characteristics and conditions by transmission (of genetic material) from parents to offspring; the total genetic makeup of an individual.
The transfer of characteristics, traits and disorders from parents to children by means of genes carried in the chromosomes of the germ cells.
The sum total of all that is inherited; that which is the result of genetic material (DNA) contained within the ovum and sperm.
Hereditary transmission is the process through which characteristics and disorders are passed from parents to their children by the influence of genes. Genes, the units of DNA (deoxyribonucleic acid) found in a person’s cells, are responsible for governing all aspects of the body’s growth and functioning. Half of a person’s genes are inherited from the mother, and the other half come from the father.
Genes are arranged into chromosomes, which are long, thread-like structures located in the cell nucleus. Most characteristics are governed by genes that come in pairs, with one gene inherited from each parent. Individuals have 22 pairs of chromosomes, known as autosomes, with each chromosome in a pair carrying one of the paired genes. Apart from the autosomes, there are also two sex chromosomes: females possess two X chromosomes, while males have one X and one Y chromosome.
A significant number of physical traits, disorders, and certain mental abilities and personality aspects are inherited. The inheritance of normal traits and disorders can be categorized into three groups: those controlled by a single pair of genes on autosomal chromosomes (unifactorial inheritance), those controlled by genes on the sex chromosomes, and those influenced by the combination of many genes (multifactorial inheritance, such as height).
Each of the gene pairs that control a trait can exist in several different forms, known as alleles.
For instance, the genes controlling eye color come in two main alleles, coding for blue and brown eye color. The brown allele is dominant over the blue allele, effectively masking it, and the blue allele is considered “recessive” to the brown allele. Each parent passes only one gene of the pair controlling a trait to their child. For example, if someone has a brown/blue combination for eye color, there is a 50 percent chance of passing on the blue gene and a 50 percent chance of passing on the brown gene to any child. These genes combine with the genes from the other parent, following dominant or recessive relationships, to determine the child’s eye color. Some genetic disorders are also inherited in a unifactorial manner, such as cystic fibrosis and achondroplasia.
Sex-linked inheritance is influenced by the two sex chromosomes, X and Y. The most apparent illustration of this inheritance is an individual’s gender. The presence of genes on the Y chromosome determines male gender, which is exclusive to males.
In males, any genetic defects on the X chromosome are more apparent since there is no second, normal X chromosome to conceal these faults, as is the case in females. Genetic defects on the X chromosome can lead to conditions such as color vision deficiency, hemophilia, and other sex-linked inherited disorders, which predominantly affect males.
Certain disorders, like diabetes mellitus and neural tube defects, may be caused by multifactorial inheritance in combination with environmental influences, such as diet and exposure to diseases or toxins.
The inheritance of traits passed down from parents to their offspring.