Inherited Traits

Inherited Trait is a fundamental concept in genetics that explains how genes are passed from parents to offspring. Genes are the instruction that tells our bodies how to grow and develop properly and, to an extent, determine what we exhibit. Inherited traits are responsible for shaping the biological identity of an individual. These are the characters that are passed down from one generation to the next generation. This article explores the concept of inherited traits with the help of Mendel’s experiment and its applications in the field of genetics.

What are Inherited Traits?

Inherited traits are the traits that are transmitted by the parents to their offspring during the process of fertilization. For if the parents have brown and black eyes, then the offspring may inherit a brown or black or a combination of both. Inherited traits are controlled by genes and the complete set of genes within an organism’s genome is called its genotype.

The complete set of observable traits that make up the structure and behavior of an organism is called its phenotype. Traits can be physical attributes, such as skin color or height, or they can be intellectual or cognitive abilities, such as intelligence, empathy, or creativity.

Examples of Inherited Traits

Some examples of inherited traits from parents are:

• Hair color (Black/brown/blonde, etc.).
• Texture and type of hair (Rough/smooth or Straight/curly).
• Dimples.
• Ability to roll tongue.
• Use of left hand/right hand.
• In females, menstruation onset and menopause.
• Sleep pattern.
• Color blindness.
• The shape of the nose.
• Skin color and texture.
• Blood group.

Types of Inherited Traits

There are two types of inherited traits. This depends on the dominance or recessive nature of the trait. In case the copies are not identical to each other, the characteristics or the trait, which is expressed phenotypically is referred to as dominant trait while the other is referred as recessive trait.

Dominant Trait	Recessive Trait
Dominant traits are always expressed when the connected allele is dominant, even if only one copy exists.	On the other hand, recessive traits are expressed only if both the connected alleles are recessive. If one of the alleles is dominant, then the associated characteristic is less likely to manifest.
Examples in humans: Almond shaped eyes, Right handedness, Detached earlobes.	Round eyes, Left handedness, Attached earlobes.

How do Traits Get Expressed?

The DNA present in the cell is responsible for making the proteins. The section of this DNA is known as a gene. These are responsible for the expression of a trait. The genes are present in the chromosomes and depend on the type of gene of the organism it can be expressed as a visible trait. Heritable traits are passed down through DNA that is transferred from the parent to the offspring. Humans, and many animals, have two copies of each chromosomes, called diploid. During the production of gametes, or sex cells, the genetic information is divided in half and only one copy of each chromosomes is packaged into the sex cells.

What are Acquired Traits?

Acquired traits are the characters which are acquired by an organism over the period of its lifetime. They do not get transferred to the next generation. e.g. loss of muscles, loss of weight etc. An acquired trait is the character developed in an individual as a result of environmental influence. These traits are not coded by the DNA of a living organism and therefore cannot be passed on to future generations.

Difference Between Acquired and Inherited Traits

The following table lists the differences between acquired and inherited traits:

Acquired Traits	Inherited Traits
Traits or characteristics which are influenced by environmental factors and cannot be inherited.	Characteristic feature that are inherited from previous generation.
Cannot pass on from one generation to another.	Pass on from one generation to another.
Do not take part in evolution.	Take part in evolution.
No change in genes or DNA is involved.	Occurs due to change in genes or DNA.
Ex: Acquiring knowledge, loss of weight.	Ex: color of eyes, skin color.

Rules for the Inheritance of Traits Mendel’s Contribution

Gregor Johann Mendel, often referred to as the ‘Father of Genetics’ has framed laws of inheritance. He had used pea plants for his experiments which are easy to grow and have greater number of visible characteristics like tall/dwarf, white/violet, wrinkled seeds.

• During his experiments there were some factors controlling the traits, which are now known as genes.
• And genes are present as a pair for a specific trait and are known as alleles.
• The tallness in a plant as a dominant trait, is denoted by ‘T’ and shortness in the plant would be a recessive trait, denoted by ‘t’ . thus the plant will be tall if it’s allele are ‘TT’ or ‘Tt’ .
• When the alleles of the genes have the same allele for a trait, they are termed as homozygous. Ex: ‘TT’ or ‘tt’ .
• And when the alleles of the genes have the different alleles for a trait, they are termed as heterozygous. Ex: Tt.
• The morphological expression of a single character is termed as the phenotype. Ex- tallness or shortness.
• Whereas the genetic constitution or the allele pair for a specific trait is termed as the genotype.
• He uses a statistical method known as Punnett square for predicting the possible genotype and phenotype of the offspring.

He conducted his experiment to find two types of inheritance namely:

Monohybrid Inheritence

Mendel took a tall (TT) and (tt) pea plant, crossed it to get the offspring. The first generation or F1 were all found to be tall showing only one of the trait of the parent. Then he self-pollinated the parent and the F1 plants. The offspring came out to be all tall, but the offspring of the F1 plants, the F2 generation did not have all tall plants. A quarter of them were short, which indicates that both traits of the parent was inherited by F1 generation. So, the genotype is – 1:2:1 and the phenotype is – 3:1. The inheritance of a trait by a pair of single alleles of a gene is termed as monohybrid inheritance.

Dihybrid Inheritence

When a pea plant with a two different traits; a plant with round green color seed (RRyy) is crossed with wrinkled yellow seed (rrYY) plant. The F1 generation turned out to have round yellow seed, RrYy, which showed the dominant traits to be round shape and yellow color. When the F1 generation were self pollinated, the F2 generation had greater variations than the parent and new combination also came up. So, the genotype is 9 different and the phenotype is 9:3:3:1. The inheritance of different trait by two pairs of alleles for it is termed as dihybrid inheritance.

Conclusion – Inherited Traits

Inherited traits are a proof to the continuity of life and the interconnectedness of generations. The study of genetics has allowed us to find the mysteries encoded in our DNA, offering insights into our physical, physiological, and behavioral characteristics. Mendel concluded that traits were not blended but remained distinct in subsequent generations, which was contrary to scientific opinion at the time. Mendel didn’t know about genes or discover genes, but he did speculate that there were 2 factors for each basic trait and that 1 factor was inherited from each parent.

FAQs on Inherited Traits

What Determines the Inherited Traits of an Organism?

Inherited traits are determined by an individual’s deoxyribonucleic acid (DNA).

What is the Role of DNA in Inheritance?

It is important in case of heredity. It packs in all the genetic information and passes it on the next generation

What are 5 Inherited Traits?

Five inherited traits are Hair color, ability to roll tongue, use of left hand /right hand, color blindness, blood group.

What do you mean by Law of Dominance?

When offspring of cross breed parent only show dominant characters in F1 generation, it is known as Law of Dominance.

Why are Acquired Traits not Inherited?

Acquired traits are changed on a phenotype level but not on a genotype level. Since these changes are not present in the genes, they can not be passed from one generation to the next.

What Determines the Process by which Traits and Characteristics are Inherited?

The rules of heredity determine the process by which traits and characteristics are reliably inherited.

Name the Plant Mendel Used for his Experiment?

Mendel selected garden pea (pisum sativum) for his series of hybridization experiments.