Definition of Phenotype
- Phenotype is a term that is used in genetics to describe all traits that can be observed in living organisms that result of interactions of the genotype and the environment.
- The word ‘pheno’ within “phenotype” is a reference to “observe so phenotype can be used to describe the observable features of an organism, like its height and color.
- The phenotype that an organism exhibits encompasses the organism’s morphology physical structure and form as well as its behavior and development in relation to its biological and physiological characteristics, and even the results from the animal.
- Phenotypes can be used to determine the difference in DNA sequences of people with different characteristics like height.
- The character of an organism is influenced by two elements which are: its expression in the genome, or its genotype as well as its interaction with environment.
- One or both of these factors can cause the phenotype that an organism exhibits.
- The phenotype of a person can vary in individuals as a result of physiological, environmental, and morphological changes resulting from the aging process.
- The phenotype variation is the foundation of natural selection in which the environment favors the longevity of individuals who are more fit over those who are not.
- This is evident when twins are involved who have identical genotypes may exhibit different phenotypes , if each experiences a different set of circumstances.
- So, without phenotypic variations evolution through natural selection would not be possible.
- The idea of phenotype variations could affect the nature of genetics in an person. One example is the silent mutations which are not able to alter the amino acid sequences, but they alter the frequency of the guanine-cytosine base pair.
- This alteration affects the G-C DNA content and, consequently leads to an increase in the thermal stability, which allows the organism to thrive in extreme temperatures.
- The phenotypes that can be observed in various species include colors of the eyes and hair texture, as also genetic diseases in humans, the size of pods and the color of leaves beak birds, etc.
Examples of phenotype
The production of melanin within humans is controlled by specific genes. Thus the differences in melanin production can be attributed to the different genetic makeup of the species. While different genes regulate melanin’s distribution throughout the body but there is one gene that regulates its production.
Therefore, people with a particular genotype could have no melanin, which results in albinism. People who suffer from albinism typically have white or a shade of pink-colored skin. Albinism is a phenotype that results of a particular genotype and as the albinism gene pool is large, cases of albinism are observed across a wide range of populations. Albinism may even be common in certain animals.
Mendel investigated a variety of types of peas as part of his research. The majority of his discoveries were based on these types of phenotypes. In the case of color of the peas both yellow and green-colored peas were examined. He observed that breeding peas with green and yellow colors resulted into half yellow as well as half-green peas, with some variations over the generations.
On the basis of this, he figured out the proportions of different phenotypes across different generations. Peas’ color is controlled by a specific gene, which produces yellow hue. If there is no gene it is possible that the pea’s color changed to green. This is why this color, yellow is dominant allele and the green color is an recessive variant.
Definition of Genotype
- The term “genotype” is that is used in genetics to describe the genetic structure of an individual that is comprised of genes that are heritable.
- Genotype refers to two alleles that are passed down through one particular gene.
- Genotypes are depicted using alphabetical letters such as Bb. is the letter representing the dominant allele, and B is the recessive allele.
- The physical traits of an individual, referred to as Phenotypes, result from the expression due to the expression and function of genes.
- But the genotype isn’t the sole factor that causes the variation in the character, and the phenotype is also dependent on other factors, such as epigenetic inheritance and environmental factors.
- Therefore, not all people who have the same genotype appear alike, nor do all people who appear similar to each other has the same genotype.
- The genomes of species are affected by a variety of variables, like mutations that alter the frequency of base pairs, or the shape of DNA sequences.
- But, the genes that are formed through somatic mutations which are acquired, not inherited, do not count as the genotype of an individual. They also don’t result in any changes in the genotypes.
- The expression of genetic variants in organisms is influenced by the genetic composition of the gene. If an allele dominant the offspring acquires dominant characteristics regardless from the allele.
- The genetic makeup of a person is based entirely on gene sequences, with the exception of occasionally heritable mutations.
- So, the genotype stays the same throughout the lifetime of an individual , unless altered by mutations.
- Similar to this, changes in phenotypes of the individual aren’t responsible for modifications to the genotype the person since genotype isn’t affected by the phenotype.
- Genotypes and phenotypes cannot be observed from outside. Genotyping is a process that needs to be done.
- The method of determining the genotype an individual is known as genotyping. It is employed for a variety of purposes, including PCR DNA sequencing as well as restrictions fragment length polymorphism (RFLP).
- Some examples of genotypes that can be seen in various animals include TT for the homozygous allele of height Tt for the heterozygous allele of height, and BB for the homozygous the color of the eyes.
Examples of genotype
The most prevalent genetic characteristic for colour of the eyes are brown. This is represented by the BB genotype. Therefore, for homozygous individuals the genotype that determines eye color is either BB or Bb. All other eye colors ranging from blue to green to grey are recessive traits that are only expressed when the genotype is homozygous-recessive, bb.
In the event that the gene is homozygous the genes that determine eye color at the loci of both chromosomes need to be identical. The phenotype of an individual which is the color of the eye in an individual is determined by the resultant genotype of the phenotype.
If we take the hair type’s genotype as dominant trait H and h for recessive trait. The genotype for curly hair could be Hh or HH. This genotype encodes the protein responsible for causing the hair to become curly. When the gene is HH one, then the person would have curly hair. However in the case of heterozygous genotypes hair will be curly, which falls between straight and curly hair.
To make hair straight it is necessary for the genotype to be hh since the recessive nature of straight hair makes it a condition. With complete dominance curly hair can be observed in those who have the heterozygous condition.
Differences between Phenotype and Genotype (Phenotype vs Genotype)
|Basis for Comparison||Phenotype||Genotype|
|Definition||Phenotype is a term that is used in genetics to denote the traits that are visible in living organisms that result of interactions of the genotype and the environment.||Genotype is a term in the field of genetics to refer to the genetic makeup of an individual, which is composed from heritable genetic genes.|
|Observable||Phenotypes can be observed as observable characteristics visible within the physique of an living thing.||Genotypes are found within the chromosomes belonging to people and therefore can’t be detected.|
|Inherited||Phenotypes cannot be inherited.||Genotypes are inherited in part from one individual to their offspring, as one of two alleles that are present during sexual reproduction.|
|Consists of||Phenotype comprises a variety of features like physical shape and structure, as well as its growth and behavior and its physiological and biological characteristics, and even the product that the animal produces.||Genotype refers to the hereditary characteristics of an organism that may or might never be passed on to the following generation.|
|Affected by||Phenotypes are influenced by the genetic makeup of the organism, as well as other environmental factors.||The genotype is affected by genetic composition of an individual which can be affected by the process of sexual reproduction. Hereditary mutations may also alter the genome of the organism.|
|Relation||The same phenotype might be expressed by the identical genotype.||The same genotype will always result in the same phenotype except for heritable mutations.|
|Determined by||Phenotypes can be identified easily by looking at the organism.||Genotypes are identified through using the method of genotyping using different scientific methods such as Polymerase Chain Reaction (PCR) and RFLP.|
|Environmental factors||Phenotypes are influenced by environmental conditions.||Genotypes aren’t affected by environmental influences.|
|Changes||Phenotypes can change over the life of a person as does the color of their hair.||Genotypes are the same throughout the lifetime of an person.|
|Examples||The phenotypes that can be observed in different organisms include colors of the eyes and hair texture, as also genetic diseases in humans, the size of pods and the color of leaves beak birds, etc.||Some examples of genotypes that can be seen in various species include TT as the homozygous allele of height Tt for the heterozygous allele of height, and BB for the homozygous the color of the eyes.|