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Phenotype Vs Genotype- Definition, 10 Differences, Examples

Phenotype Vs Genotype Overview

Phenotype Definition

In genetics, the word “phenotype” is used to describe all the features that may be seen in an organism as a consequence of the interaction between its genotype and its environment.

  • The word “pheno” in the word “phenotype” means to “observe,” hence it is used to describe an organism’s observable traits, such as its height and colour.
  • An organism’s phenotype includes its shape, physical make-up and composition, growth and behaviour, biological and physiological characteristics, and even the output of the organism.
  • In order to determine the variations in DNA sequences across people with different features like height, phenotypes are employed.
  • An organism’s genotype, or how its genome is expressed, and how it interacts with its environment, or environmental factors, determines its phenotype.
  • The phenotype of an organism may be caused by one, both, or both of the factors.
  • Due to morphological, physiological, and environmental changes brought on by ageing, variation in phenotype is seen even within one person.
  • Natural selection, when the ecosystem encourages the survival of fitter people over less fit ones, is based on the variety of phenotypes.
  • Twins are a good example of this phenomenon since identical twins can have distinct phenotypes depending on the environment they are exposed to.
  • Therefore, evolution via natural selection is impossible without phenotypic diversity.
  • A change in phenotype might have effects regardless of an individual’s genetic makeup. This is illustrated by silent mutations, which do not affect the amino acid sequences but change the frequency of guanine-cytosine base pairs.
  • This change modifies the G-C ratio in the genome, enhancing thermal stability and allowing the organism to thrive in high-temperature environments.
  • Blood type, eye colour, hair texture, inherited diseases in humans, pod size and leaf colour, bird beaks, etc., are some instances of phenotypes presented by many species.

Genotype Definition

The genetic makeup of an individual, which consists of heritable genes, is referred to as the genotype in the study of genetics.

  • The two alleles inherited for a particular gene are commonly known as the genotype of an individual.
  • The dominant allele in a genotype is denoted by the letter B, while the recessive allele is denoted by the letter b.
  • The expression of these genes defines the phenotypes, or physical characteristics, of a person.
  • The phenotype, however, is influenced by a variety of variables, including inherited epigenetics and environmental influences, and is not only determined by genotype.
  • As a consequence, neither all individuals with a similar genotype nor all individuals with similar appearances contain the same genotype.
  • Numerous variables, like mutations which modify the incidence of base pairs or the structure of DNA sequences, affect the frequency of base pairs, have an impact on an organism’s genotype.
  • However, the genotype of an individual does not include genes created by a somatic mutation, which is acquired as opposed to inherited. Additionally, the genotypes are unaffected by these alterations.
  • The genotype’s genetic makeup affects how it is expressed in living things. When a dominant allele is present, children will always inherit the dominant characteristics irrespective of the other allele.
  • Except for occasional heritable mutations, the genotype of a character is completely governed by the gene sequences.
  • Thus, unless mutated, a person’s genotype does not change throughout the course of their lifetime.
  • Similar to how genotype is unaffected by phenotype, phenotypic changes in an individual do not result in any changes to genotype.
  • Like phenotypes, genotypes cannot be seen from the outside. Instead, techniques like genotyping should be used.
  • Genotyping is the method that determines a person’s genotype, and it has a range of applications, such as PCR, DNA sequencing, and restriction fragment length polymorphism (RFLP).
  • Multiple species exhibit the genotypes TT, which is the homozygous allele for height; Tt, which is the heterozygous allele for height; and BB, which is the homozygous allele for eye colour.

Key Differences (Phenotype Vs Genotype)

Basis for Comparison Phenotype Genotype
Definition Phenotype is a term used in genetics to refer to all the observable traits in organisms as a result of the interaction of the genotype with the environment. Genotype is a term used in genetics used to refer to the genetic composition of an individual consisting of heritable genes.
Observable Phenotypes are observable traits that can be seen on the body of the organism. Genotypes are present within the chromosomes of the individuals and thus cannot be observed.
Inherited Phenotypes are not inherited. Genotypes are partly inherited from an individual to the offspring as one of the two alleles during sexual reproduction.
Consists of Phenotype consists of various traits like physical form and structure, its development and behavior, its biological and physiological properties, and even the products of the organism. Genotype consists of hereditary characteristics of an organism which may or may not be expressed in the next generation.
Affected by Phenotype is affected by the genotype of the organism and other environmental conditions. The genotype is affected by the genetic composition of the individual, which, in turn, is affected by sexual reproduction. Heritable mutations might also affect the genotype of the organism.
Relation The same phenotype may or may not be expressed from the same genotype. The same genotype always results in the same phenotype, unless heritable mutations.
Determined by Phenotypes can be determined easily by observing the organism. Genotypes are determined by the process of genotyping in various scientific methods like Polymerase Chain Reaction (PCR) and RFLP.
Environmental factors Phenotypes are affected by environmental factors. Genotypes are not affected by environmental factors.
Changes Phenotypes might change during the lifetime of an individual like the color of the hair. Genotypes remain the same throughout the life of the individual.
Examples Examples of phenotypes seen in various organisms include the blood group, eye color, and hair texture as well as genetic diseases in humans, pod size and color of leaves, beak birds, etc. Examples of genotypes seen in different animals include TT as the homozygous allele for height, Tt for the heterozygous allele for height, and BB for homozygous allele for eye color.

Examples of phenotype

Melanin production

  • Human melanin synthesis is governed by specific genes; hence, changes in melanin synthesis are due to differences in genotype.
  • Despite the fact that numerous genes affect how much melanin is dispersed all over the body, just one gene influences how much is created.
  • Consequently, individuals with a specific genotype may develop albinism due to the lack of melanin production.
  • Consequently, albinos exhibit skin that is normally white or pink in colour.
  • Due to the fact that albinism is a phenotype that may be induced by a specific genotype and contains a large gene pool, it is prevalent in several groups.
  • Some animals may even have a high prevalence of albinism.

Mendels’ Peas

  • Mendel investigated many pea phenotypes as part of his research.
  • These characteristics served as the basis for nearly every one of his findings.
  • In the case of the peas’ hue, green and yellow-colored peas were studied. He observed that crossing yellow and green peas yielded peas with equal proportions of each colour. with considerable fluctuation between generations.
  • He calculated the ratios of various traits in many generations using this information.
  • Yellow hue in peas is produced by a specific gene that codes for colour. The colour of the pea turned green while this gene was absent.
  • As a consequence, the colour green is the recessive allele while the colour yellow is the dominant allele.

Examples of a genotype

Eye colour

  • BB is the predominant genotype for brown eyes, which is a dominant heritable trait.
  • In homozygous individuals, the genotype for eye colour will be BB or bb.
  • All other eye colours, including blue, green, and grey, are recessive traits that are exclusive to homozygous-recessive (bb) people.
  • If the genotype is homozygous, the eye colour genes on the two chromosomal sites should be identical.
  • The phenotype of an individual, or the colour of their eyes, is determined by their genotype for that attribute.

Curly hair

  • The genotype for curly hair would be HH or Hh if the dominant trait for hair type is H and the recessive trait is H.
  • The protein responsible for curly hair is encoded by this genotype.
  • If the genotype is HH, the individual will have curly hair. However, if the genotype is heterozygous, the individual will have wavy hair, which lies between curly and straight.
  • Given that straight hair is a recessive trait, the genotype hh would be required for the hair to be straight.
  • The curly hair trait is completely dominant in individuals with the heterozygous situation.

References and Sources

  • 2% – https://biodifferences.com/difference-between-phenotype-and-genotype.html
  • 1% – https://www.britannica.com/science/phenotype
  • 1% – https://www.biologyonline.com/dictionary/phenotype
  • 1% – https://en.wikipedia.org/wiki/Phenotype
  • 1% – https://en.wikipedia.org/wiki/Genotype
  • 1% – https://byjus.com/biology/genotype-and-phenotype-difference/
  • <1% – https://www.spectrumnews.org/news/genetics-identical-twins-not-so-similar/
  • <1% – https://www.slideshare.net/SRMegh/silent-mutation-2
  • <1% – https://www.researchgate.net/publication/329214501_Biparental_Inheritance_of_Mitochondrial_DNA_in_Humans
  • <1% – https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3563493/
  • <1% – https://www.ncbi.nlm.nih.gov/books/NBK7908/
  • <1% – https://quizlet.com/361810829/chapter-22-and-23-darwin-flash-cards/
  • <1% – https://quizlet.com/359071278/genetics-ch-1-flash-cards/
  • <1% – https://quizlet.com/25549586/genetics-flash-cards/
  • <1% – https://quizlet.com/114950720/ch-15-ch-16-study-guide-flash-cards/
  • <1% – https://curlybetty.wordpress.com/2011/05/10/curly-hair-genetics-heredity/
  • <1% – https://biologywise.com/homozygous-vs-heterozygous
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