Introduction to Phenotype and Genotype
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 regions, certain races have broad lips as their dominant Gene.
FAQs on Difference Between Genotype and Phenotype
1. Is it necessary to have Genotype compatibility for marriage? Why?
People who are incompatible based on their Genotype, have a big risk of giving birth to an immature child. A child can be born with serious diseases such as sickle cell disease. It reduces the lifespan of a child. This is the reason why before getting serious with a partner, one should have to pass a Genotype test. There was a high mortality rate in the past among children who were born to parents with incompatible Genotypes. A few Genotypes determine one's traits and the traits of future children. They are AA, AS, AC, and SS These are haemoglobin Genes. Genotype AC is uncommon, together with Genotype SS, it is considered abnormal. In Genetics, it is referred to as sickle cells. AA and AS are normal Genotypes.
2. How is blood type inherited?
Blood type in Humans is inherited similarly to many other traits. Punnett squares are used to determine the Genotype and Phenotype of offspring. There is not a single inheritance pattern that governs all blood types. Recessive blood type is always “O”. It requires two copies of the O Alleles for an offspring to demonstrate the O Phenotype. A and B are blood types and both are dominant. So, as a result, there can be blood type A or B by inheriting two copies of A or B Allele and one copy of the Allele O.
3. What can be considered as the examples of Genotype in Humans?
1. Height: In Human beings, an example of a Genotype, will be the height difference between various individuals. In the Gene makeup of Humans, there are two types of the Gene present in it. The first of these two Genes is the tall variety (T) and the other one is the short variety (s). These Genes (T and s) are also called Alleles. The combination of these two will determine the height of an individual Human being.
There are four ways in which these Genes can be present in a Human body, the four are T.s, s.s, T.T, s.T. The T Gene is considered the dominant in the two, and out of the four combinations, the one having the Gene T will determine that the individual be a pure breed and carry the height of the T Genetic information. Hence, there is only one possibility out of the four in which the resulting offspring will be of short height.
2. Freckles or No Freckles: The position and size of freckles or if a person will develop one or not is determined entirely on the Gene or the information passed from parent to child which is carried in the cell of the Genotype. Dominant Genotypes will determine if the child develops freckles or not.
3. Lactose Intolerance: We will be able to find many children who can’t easily digest milk. This behaviour is the trait of lactose intolerance that is passed from the dominant parent to the child. The probability that the child will also be lactose intolerant is extremely high.
4. Is there any relation between Genotype and Phenotype?
The Genotype and Phenotype are two pretty different concepts but are also very closely related to each other. Phenotypes are the characters of an Organism that are observable or visible by the naked eyes, meanwhile, the Genotypes are the traits that cannot be observed by naked eyes and are inherited from the parents. But the Phenotypes traits can be an outcome of the expression of the Genes of an individual, which are traits of Genotypes. Hence, the Genotype in a way guides much of the Phenotype traits.
Hence, establishing the relationship between Genotype and Phenotype. An example could be the height of an individual, the height of an individual is determined by a difference in the individual's Gene from the other individual and hence is a Genotype, but these differences can be observed with the help of just the naked eye, hence it is also a Phenotype.
5. Give examples of characteristics that are both Genotype and Phenotype?
1. Hair Colour/Eye Colour: Hair colour and eye colour of an individual or a species, depends on the dominant Gene present in them. This distinction of Genes can only be found with the help of intensive laboratory experimentations, hence is a Genotype. But this characteristic is also observable by the naked eye, hence is a type of Phenotype too.
2. Height: the height of an individual is also determined by variations in the Genes of an individual from another individual and hence can be considered as a Genotype. But this difference can also be observed with the help of just the naked eye, hence it is also a Phenotype.
