[Biology Class Notes] on Difference Between Genotype and Phenotype Pdf

Genotype can be described as the Genetic makeup of an Organism. As Humans are diploid Organisms, they have two Alleles at each Genetic position, with one Allele inherited from each parent. Phenotype refers to the physical properties of an Organism, which can be observed with our eyes. These include the Organism’s appearance, development, behavior, height, color of eyes, hairs, etc. The concept of Genotype and Phenotype was introduced by Johannsen in 1909, in his textbook on Heredity research.

He further developed this concept in a paper named “The Genotype Conception of Heredity” in 1911. An Organism’s Genotype affects its Phenotype. Change in the Environment also affects Phenotype.

Comparison Chart Between Genotype and Phenotype

Factors Affecting Genotype And Phenotype

The Genotype of a person can be affected by the Environment in which the person lives and the internal Environment of a person’s body such as Hormones and Metabolism. Phenotype is affected by the Genotype of a person.

Genotype In Biology

In biology, Genotype can be considered as the variation in Genes, which determines certain characteristics. Gene is basically a part of DNA that encodes some traits, these different traits are just called a Genotype.

The precise arrangement of the Nucleotides in a Gene can differ between copies of the same Gene. Nucleotides are each composed of various Phosphate groups such as sugar and a base. Thus, Genes can exist in various forms across the different species, or even between the individuals of the same species.

Genotype helps to determine the heredity potentials and limitations of an individual from the Embryonic stage through Adulthood. Among Sexually Reproducing Organisms, a Genotype contains the entire complex of Genes inherited from both parents.

Examples of Genotype

Example 1

In the pea plant, the possible Genotypes for the flower- color Gene was red – red, red- white, and white- white.

Example 2

Considering the Genotype for height in a species of a pea plant, T is for tall variety and s small variety. T and s can be known as Alleles as they are the variations in the same character, called “height of a pea plant”. If T is dominant, four possible combinations will be Ts, ss, TT, sT. It is considered that pure breed of plants is TT and ss, then the probability of offspring being short is 1 in 4.

Phenotype In Biology

Physical characters of an individual that are observable, is the Phenotype of that individual. The main difference between the Phenotype and that of the Genotype is that the Genotypes are inherited from the parents but Phenotypes are majorly not inherited from the parents of the offspring. Also, a Phenotype can be influenced by Genotypes and many other factors like the surrounding Environment and lifestyles. Like the colour of some animals changes according to their diet, like flamingos get their pink colour from the Organisms in their diets.

Examples of Phenotype

• Sound of your voice 

• Length of a fox’s tail

• Colour of stripes on the cat

• An individual’s shoes size

• Size and shape of the spots on the dog’s back

Types of Genotype

A combination of Alleles situated on corresponding chromosomes determines a person’s specific traits. The Genes responsible for traits such color of the skin can be the example of a Genotype.

There are three types of Genotypes. They can be distinguished based on Alleles of a person.

• Homozygous dominant, PP

• Heterozygous, Pp

• Homozygous recessive pp

The ability to survive intensive breeding depends on adjusting the system of a Genotype to different conditions. Different species have different Genotype adaptability, hence there is a constant natural selection.

The Strongest Genotype

The Genotype having more dominant Genes are considered as strongest. Dark hair, Right handedness, Brown eyes, Broad eyebrows, Left thumb crossing, Long eyelashes, Left arm over right, Broad lips, etc.  In hot climate reg
ions, certain races have broad lips as their dominant Gene.