Inheritance Definition: Meaning, Synonyms, Issues, & Facts

Edited By Irshad Anwar | Updated on Jul 02, 2025 06:17 PM IST

Inheritance is the process by which traits are passed from parents to offspring through genes. It forms the basis of heredity and explains why offspring resemble their parents. The study of inheritance involves knowledge of genetic principles like Mendel's laws, dominant and recessive traits, and variations caused by genetic combinations. In this article, inheritance definition, basic concepts of inheritance, Mendelian Inheritance, Non-Mendelian Inheritance, and Sex-linked Inheritance are discussed. Inheritance is a topic of the chapter Principles of Inheritance and Variation in Biology.

This Story also Contains

Inheritance Definition in Biology
Basic Concepts of Inheritance
Mendelian Inheritance
Non-Mendelian Inheritance
Sex-Linked Inheritance

Inheritance Definition: Meaning, Synonyms, Issues, & Facts

Inheritance Definition in Biology

Biological inheritance is a process in which genetic information is passed from parents to offspring. Put differently, the transfer of traits from one generation into the following takes place through genes, which are described to be the basic units of heredity. Understanding inheritance is therefore important if one needs to understand how traits and characteristics are passed on to cause variations within a species.

Inheritance is the basis for the major field of biology known as genetics, which is tailored to variation and the transmission of traits.

The study of inheritance allows prediction regarding the patterns of traits and accounts for particular disorders genetically transmitted in families due to abnormalities of the genetic material. It also finds application in techniques of genetic engineering for health and agriculture. The basic principles of inheritance form the basis of advances in medicine, biotechnology, and evolutionary biology.

Basic Concepts of Inheritance

The concept of inheritance is described below:

Genes and Chromosomes

Genes are short stretches of DNA that encode proteins, which determine the expression of certain traits. They are located on chromosomes, which are long helices of DNA wrapped around proteins called histones. There are 23 pairs of chromosomes in humans, with each one containing thousands of genes. Chromosomes ensure the proper distribution of genetic material during cell division and hence may be considered responsible for heredity.

Alleles

Alleles are the variants of genes that produce variation in a given trait. Dominant alleles mask the presence of other alleles, although sometimes allele expression is only seen if the organism has two copies of the allele. For example, the allele for purple flowers, P, is dominant over that for the white version, p, at the same locus in pea plants. An individual who contains two copies of the same allele for a given trait is homozygous (PP or pp). An individual who contains different alleles at a particular locus is heterozygous; in this case, that would be Pp.

Genotype and Phenotype

Genotype refers to the genetic constitution of an organism, that is, all its genes and alleles. The phenotype is the expression of the genotype resulting from the interaction of the genotype with environmental factors. In pea plants, the PP or Pp genotype will produce the phenotype known as purple flowers and the pp genotype will produce white flowers.

Also Read:

NEET Highest Scoring Chapters & Topics

Know Most Scoring Concepts in NEET 2024 Based on Previous Year Analysis.

Know More

Mendelian Inheritance

The Mendelian Inheritance is given below:

Laws of Mendelian Inheritance

Gregor Mendel, the Father of Genetics, formulated laws of inheritance based on his experiments with pea plants. The Law of Segregation says that as gametes are made, the two alleles for a given trait separate, and thus each contains just one allele. The Law of independent assortment states that during the formation of gametes, alleles segregate separately, resulting in each possible genetic combination.

Monohybrid Cross

A monohybrid cross is a cross for a single trait. All possible genotypes and phenotypes that will result in offspring from parents of known genotypes can be predicted using a Punnett square. Such as crossing homozygous dominant (PP) with homozygous recessive (pp) will yield all heterozygous offspring (Pp) with the dominant phenotype.

Dihybrid Cross

A dihybrid cross-examines two traits simultaneously. A Punnett square for a dihybrid cross is larger because it includes all possible combinations of alleles for both traits. For instance, crossing plants heterozygous for the seed shape (Rr) and seed colour (Yy) gives offspring in the ratio 9:3:3:1, a result that describes Mendel's Law of Independent Assortment.

Non-Mendelian Inheritance

The Non-Mendelian Inheritance is given below:

Incomplete Dominance

Incomplete dominance is a phenomenon where the expression of the heterozygous phenotype is an intermediate mixture of two homozygous phenotypes. For instance, in snapdragons, crossing the flower colour with red (RR) with white (rr) results in the pink colour in the offspring, Rr.

Codominance

In codominance, both alleles are expressed fully in the heterozygote. The classical example is the ABO blood group system in human beings. For example, I^A and I^Balleles produce A and B antigens on the red blood cells and result in AB blood type.

Multiple Alleles

Multiple alleles refer to the presence of more than two alleles of genes in a population. Inheritance of blood group systems ABO typifies this, whereby three alleles (IA, IB, i) determine four blood types: A, B, AB, O.

Polygenic Inheritance

Polygenic inheritance is a condition where more than one gene controls a particular trait, causing continuous variations. Skin colour in human beings is a polygenic character controlled by several genes which contribute to the gradation of skin colours found amongst the population.

Sex-Linked Inheritance

The Sex-linked Inheritance is described below:

Sex Chromosomes

Sex is determined by the sex chromosomes, X and Y. For sex determination to take place, what is required is that females must have two X's, while males should be XY. These contain genes for sex-linked characteristics.

X-Linked Inheritance

X-linked inheritance refers to genes on the X chromosome. Specific disorders such as colour blindness and haemophilia are more common in males than females since there is only one X chromosome, carrying a single recessive allele of some genes on the X chromosome that expresses the trait.

Y-Linked Inheritance

Y-linked inheritance refers to genes on the Y chromosome. Y-linked genes have a transmission pattern of father to son. Traits controlled by Y-linked genes are very rare and usually involved with male-specific development.

Also Read:

Allele Definition	Gene Definition
Epistasis	Test Cross
Gene Interaction	Gene Mapping

Frequently Asked Questions (FAQs)

1. What is inheritance in biology?

Inheritance in biology refers to the process by which genetic information is passed from parents to offspring.

2. What is inheritance in biology?

Inheritance in biology refers to the passing of traits from parents to offspring through genetic material. It's the process by which characteristics are transmitted from one generation to the next, forming the basis of heredity and evolution.

3. What are the basic principles of Mendelian inheritance?

The basic principles include the Law of Segregation and the Law of Independent Assortment, which describe how alleles separate and assort independently during gamete formation.

4. How does incomplete dominance differ from codominance?

In incomplete dominance, the heterozygous phenotype is intermediate between the two homozygous phenotypes. In codominance, both alleles are fully expressed in the heterozygous condition.

5. What are some examples of sex-linked genetic disorders?

Examples include colour blindness and haemophilia, which are often inherited through the X chromosome.

6. How is genetic testing used in modern medicine?

Genetic testing is used to diagnose genetic disorders, determine ancestry, and inform personalised medicine treatments.

7. What's the difference between genotype and phenotype?

Genotype refers to the genetic makeup of an organism, while phenotype is the observable physical or biochemical characteristics. The genotype determines the potential traits, but environmental factors can influence how these genes are expressed in the phenotype.

8. What role does DNA play in inheritance?

DNA (Deoxyribonucleic Acid) is the molecule that carries genetic instructions for the development, functioning, growth, and reproduction of all known living organisms. It serves as the hereditary material, passing genetic information from parents to offspring.

9. How does meiosis contribute to genetic variation?

Meiosis, the cell division process that produces gametes, contributes to genetic variation through processes like crossing over and independent assortment. These mechanisms shuffle genetic material, creating unique combinations of alleles in offspring.

10. Can acquired characteristics be inherited?

Generally, acquired characteristics (those developed during an organism's lifetime) are not inherited through genetic means. However, recent studies in epigenetics suggest that some environmental influences can affect gene expression in ways that may be passed to offspring.

11. How do environmental factors influence gene expression and inheritance?

Environmental factors can influence gene expression through epigenetic modifications, which can alter how genes are read without changing the DNA sequence. While these changes are not typically inherited in the traditional sense, they can sometimes persist across generations, affecting inheritance patterns.

12. What is meant by "nature vs. nurture" in the context of inheritance?

"Nature vs. nurture" refers to the relative importance of an individual's genetic inheritance (nature) versus personal experiences and environmental factors (nurture) in determining their traits and characteristics. Most traits are influenced by both genetic and environmental factors.

13. What is heterosis or hybrid vigor in genetics?

Heterosis, or hybrid vigor, is the improved or increased function of any biological quality in a hybrid offspring. It often results in offspring that are larger, faster growing, and more vigorous than either parent. This phenomenon is widely used in agriculture to produce more robust crops and livestock.

14. How do transposable elements affect inheritance?

Transposable elements, or "jumping genes," are DNA sequences that can move from one location in the genome to another. They can cause mutations, alter gene expression, and contribute to genome evolution. Their movement can be inherited and can lead to genetic variation within populations.

15. What is genetic drift and how does it affect inheritance in populations?

Genetic drift is the change in allele frequencies in a population due to random chance rather than natural selection. It can lead to the loss of genetic variation, especially in small populations, and can affect the inheritance patterns of traits within that population over generations.

16. How does Mendel's work relate to our understanding of inheritance?

Gregor Mendel's work laid the foundation for our understanding of inheritance. Through his experiments with pea plants, he discovered the basic principles of heredity, including the concepts of dominant and recessive traits, which form the basis of modern genetics.

17. How do dominant and recessive alleles affect inheritance?

Dominant alleles mask the effect of recessive alleles when both are present. For a recessive trait to be expressed, an individual must inherit two copies of the recessive allele. This interaction between dominant and recessive alleles determines many inherited traits.

18. What is meant by "Mendelian inheritance"?

Mendelian inheritance refers to the patterns of inheritance first observed and described by Gregor Mendel. It includes concepts such as dominant and recessive traits, the law of segregation, and the law of independent assortment, which explain how traits are passed from parents to offspring.

19. What is penetrance in genetics?

Penetrance refers to the proportion of individuals with a particular genotype who express the associated phenotype. Complete penetrance means all individuals with the genotype show the trait, while incomplete penetrance means only some individuals with the genotype express the trait.

20. How do polygenic traits differ from single-gene traits in inheritance?

Polygenic traits are influenced by multiple genes, each contributing a small effect, resulting in a continuous range of phenotypes. Single-gene traits, in contrast, are controlled by one gene and often show discrete phenotypes. Height is an example of a polygenic trait, while blood type is a single-gene trait.

21. How do multiple alleles affect inheritance?

Multiple alleles occur when a gene has more than two variants in a population. This can lead to more complex inheritance patterns than simple dominant-recessive relationships, as seen in human blood types where there are three alleles (A, B, and O) for the ABO gene.

22. What is incomplete dominance in inheritance?

Incomplete dominance is a form of inheritance where one allele is not completely dominant over the other. Instead, the heterozygous phenotype is intermediate between the two homozygous phenotypes. An example is the pink color in snapdragon flowers, which is a blend of red and white alleles.

23. How does codominance differ from incomplete dominance?

In codominance, both alleles in a heterozygous genotype are fully expressed, resulting in a phenotype that displays both traits. This differs from incomplete dominance where the phenotype is a blend. An example of codominance is the AB blood type, where both A and B antigens are expressed.

24. How does epistasis affect inheritance patterns?

Epistasis is a form of gene interaction where the expression of one gene is affected by the expression of one or more other genes. This can lead to more complex inheritance patterns, as the phenotype is determined by the interaction of multiple genes rather than a single gene.

25. What is genomic imprinting and how does it affect inheritance?

Genomic imprinting is an epigenetic phenomenon where certain genes are expressed in a parent-of-origin-specific manner. This means that the expression of these genes depends on whether they were inherited from the mother or the father, leading to non-Mendelian inheritance patterns.

26. What is a pedigree and how is it used in studying inheritance?

A pedigree is a diagram that shows the occurrence and appearance of phenotypes within a family tree. It's used to track the inheritance of specific traits, identify patterns of inheritance, and predict the probability of certain genetic conditions in future generations.

27. How do sex-linked traits differ from autosomal traits in inheritance?

Sex-linked traits are associated with genes located on sex chromosomes (typically the X chromosome), while autosomal traits are associated with genes on non-sex chromosomes. Sex-linked traits often show different inheritance patterns in males and females due to the presence of only one X chromosome in males.

28. How do mutations impact inheritance?

Mutations are changes in DNA sequence that can alter gene function. They can be inherited if they occur in germ cells (eggs or sperm) and can introduce new alleles into a population. Mutations are a source of genetic variation and can lead to new traits or genetic disorders.

29. What is genetic recombination and how does it affect inheritance?

Genetic recombination is the exchange of genetic material between chromosomes during meiosis. This process creates new combinations of alleles, increasing genetic diversity in offspring and playing a crucial role in evolution by generating new genetic variations.

30. What is meant by "linked genes" in inheritance?

Linked genes are genes that are located close to each other on the same chromosome. These genes tend to be inherited together more frequently than genes on different chromosomes, as they are less likely to be separated during the process of genetic recombination.

31. What is pleiotropy in genetics?

Pleiotropy occurs when a single gene influences multiple, seemingly unrelated phenotypic traits. This means that a change in one gene can affect various aspects of an organism's phenotype. An example is the gene responsible for sickle cell anemia, which also provides resistance to malaria.

32. How does genetic anticipation affect inheritance patterns?

Genetic anticipation is a phenomenon where certain genetic disorders become more severe or appear at an earlier age in successive generations. This is often associated with the expansion of repeated DNA sequences, as seen in diseases like Huntington's disease.

33. How do chromosomal abnormalities affect inheritance?

Chromosomal abnormalities, such as deletions, duplications, or translocations, can significantly affect inheritance patterns. They can lead to missing or extra copies of genes, altered gene function, or changes in gene regulation, resulting in various genetic disorders or syndromes.

34. What is the difference between vertical and horizontal gene transfer?

Vertical gene transfer is the transmission of genetic material from parent to offspring, which is the typical mode of inheritance in most organisms. Horizontal gene transfer involves the transfer of genetic material between different species or between unrelated individuals of the same species, and is more common in bacteria.

35. How does DNA methylation affect gene expression and inheritance?

DNA methylation is an epigenetic modification that can turn genes on or off without changing the DNA sequence. While DNA methylation patterns are generally reset during gamete formation, some patterns can be inherited, potentially affecting gene expression in offspring.

36. What is genetic mosaicism and how does it complicate inheritance patterns?

Genetic mosaicism occurs when an individual has two or more genetically distinct cell populations arising from a single fertilized egg. This can lead to complex and unpredictable inheritance patterns, as different cells in the body may have different genetic compositions.

37. How do gene interactions like complementation affect inheritance?

Complementation occurs when two different mutant alleles of a gene, each causing a loss of function on its own, can compensate for each other when present together. This can lead to the restoration of the wild-type phenotype in heterozygotes, complicating inheritance patterns.

38. What is the role of non-coding DNA in inheritance?

Non-coding DNA, once thought to be "junk," plays crucial roles in gene regulation, chromosome structure, and evolution. It can affect how genes are expressed and inherited, influencing traits without directly coding for proteins.

39. How do copy number variations (CNVs) impact inheritance?

Copy number variations are segments of DNA that are repeated, and the number of repeats varies between individuals. CNVs can affect gene dosage and function, leading to variations in traits or susceptibility to certain conditions, and can be inherited from parents to offspring.

40. What is meant by "inheritance of acquired characteristics" in Lamarckian evolution?

The inheritance of acquired characteristics, proposed by Lamarck, suggested that traits developed during an organism's lifetime could be passed on to offspring. While this idea is largely discredited in its original form, modern epigenetics has shown that some environmental influences can affect gene expression in ways that may be inherited.

41. How does genetic linkage affect the inheritance of traits?

Genetic linkage occurs when genes are physically close on a chromosome and tend to be inherited together. This can lead to deviations from expected Mendelian ratios and can be used to map the relative positions of genes on chromosomes.

42. What is meant by "inheritance of mitochondrial DNA"?

Mitochondrial DNA is inherited solely from the mother in most species. This non-nuclear DNA inheritance pattern allows scientists to trace maternal lineages and is used in evolutionary studies and forensic investigations.

43. How do gene duplications contribute to evolution and inheritance?

Gene duplications create extra copies of genes, which can then evolve new functions while the original copy maintains its role. This process contributes to genetic diversity and the evolution of new traits, affecting inheritance patterns over evolutionary time.

44. What is transgenerational epigenetic inheritance?

Transgenerational epigenetic inheritance refers to the transmission of epigenetic marks (such as DNA methylation patterns) from one generation to the next, potentially influencing phenotypes in offspring without changes to the DNA sequence itself.

45. How does assortative mating affect inheritance in populations?

Assortative mating, where individuals with similar phenotypes mate more frequently than would be expected by chance, can affect the distribution of traits in a population over generations. This can lead to increased genetic similarity within subgroups of a population.

46. What is the concept of "selfish genes" in inheritance?

The "selfish gene" concept, proposed by Richard Dawkins, suggests that genes are the units of natural selection and act to propagate themselves, sometimes at the expense of the organism. This perspective can explain certain inheritance patterns and evolutionary phenomena.

47. How do genomic imprinting disorders affect inheritance patterns?

Genomic imprinting disorders result from abnormal expression of imprinted genes. These disorders show unusual inheritance patterns because the expression of the gene depends on which parent it was inherited from, leading to parent-of-origin effects.

48. What is the role of non-coding RNAs in inheritance?

Non-coding RNAs, such as microRNAs and long non-coding RNAs, play important roles in gene regulation. They can be inherited and can affect gene expression in offspring, contributing to phenotypic variation and inheritance patterns.

49. How does genetic background affect the expression of inherited traits?

Genetic background refers to all genes in an organism other than the specific gene(s) under study. It can significantly influence how inherited traits are expressed, as genes often interact in complex ways to produce phenotypes.

50. What is meant by "inheritance of epigenetic memory"?

Inheritance of epigenetic memory refers to the transmission of epigenetic marks across generations, potentially allowing offspring to "remember" environmental experiences of their parents or ancestors. This concept challenges traditional views of inheritance and adaptation.

51. How do mobile genetic elements affect genome stability and inheritance?

Mobile genetic elements, such as transposons, can move within the genome, potentially causing mutations or altering gene expression. Their activity can be inherited and contribute to genetic variation and genome evolution over time.

52. What is the concept of "missing heritability" in genetics?

"Missing heritability" refers to the observation that known genetic variants often explain only a small portion of the heritability of complex traits. This suggests that other factors, such as rare variants, epigenetic modifications, or complex gene interactions, may play significant roles in inheritance.

53. How does genetic hitchhiking affect inheritance and evolution?

Genetic hitchhiking occurs when a neutral allele increases in frequency because it is physically close to a beneficial allele on the same chromosome. This process can affect the inheritance and distribution of genetic variants in a population over time.

54. What is the role of gene-environment interactions in inheritance?

Gene-environment interactions occur when the effect of a gene on a trait depends on environmental factors, or vice versa. These interactions complicate inheritance patterns and contribute to the variability in how inherited traits are expressed in different individuals or populations.

55. How do chromosomal inversions affect inheritance patterns?

Chromosomal inversions are structural changes where a segment of a chromosome is reversed end to end. They can suppress recombination in heterozygotes, leading to the inheritance of large blocks of genes together. This can maintain combinations of alleles and affect evolution and speciation.