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Genotype-phenotype distinction

 

 
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Genotype-phenotype distinction
 
 
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The genotype-phenotype distinction is drawn in genetics
Genetics

Genetics , a discipline of biology, is the science of heredity and Genetic variation in living organisms. The fact that living things inherit traits from their parents has been used since prehistoric times to improve crop plants and animals through selective breeding....
. "Genotype
Genotype

The genotype is the trait we can't see. The genotype is the Genetics constitution of a cell, an organism, or an individual usually with reference to a specific character under consideration....
" is an organism's full hereditary information, even if not expressed. "Phenotype
Phenotype

A phenotype is any observable characteristic or trait_ of an organism: such as its morphology , development, biochemical or physiological properties, or behavior....
" is an organism's actual observed properties, such as morphology
Morphology (biology)

The term morphology in biology refers to form, structure and configuration of an organism. This includes aspects of the outward appearance as well as the form and structure of the internal parts like bones and organs....
, development
Development

Development may refer to:...
, or behavior
Behavior

Behavior or behaviour refers to the action s or reactions of an object or organism, usually in Relational theory to the environment. Behavior can be conscious or Unconscious mind, overt or covert, and voluntary or involuntary....
. This distinction is fundamental in the study of inheritance of trait
Trait (biology)

A trait is a distinct variant of a phenotype character of an organism that may be inherited, environmentally determined or somewhere in between....
s and their evolution
Evolution

In biology, evolution is change in the heritability trait of a population of organisms from one generation to the next. These changes are caused by a combination of three main processes: variation, reproduction, and selection....
.

The genotype represents its exact genetic makeup — the particular set of gene
Gene

A gene is the basic unit of heredity in a living organism. All living things depend on genes. Genes hold the information to build and maintain their cell and pass genetic trait to offspring....
s it possesses. Two organisms whose genes differ at even one locus
Locus (genetics)

In the fields of genetics and evolutionary computation, a locus is a fixed position on a chromosome such as the position of a genetic marker that may be occupied by one or more genes....
 (position in their genome
Genome

In classical genetics, the genome of a diploid organism including eukarya refers to a full set of chromosomes or genes in a gamete; thereby, a regular somatic cell contains two full sets of genomes....
) are said to have different genotypes.






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The genotype-phenotype distinction is drawn in genetics
Genetics

Genetics , a discipline of biology, is the science of heredity and Genetic variation in living organisms. The fact that living things inherit traits from their parents has been used since prehistoric times to improve crop plants and animals through selective breeding....
. "Genotype
Genotype

The genotype is the trait we can't see. The genotype is the Genetics constitution of a cell, an organism, or an individual usually with reference to a specific character under consideration....
" is an organism's full hereditary information, even if not expressed. "Phenotype
Phenotype

A phenotype is any observable characteristic or trait_ of an organism: such as its morphology , development, biochemical or physiological properties, or behavior....
" is an organism's actual observed properties, such as morphology
Morphology (biology)

The term morphology in biology refers to form, structure and configuration of an organism. This includes aspects of the outward appearance as well as the form and structure of the internal parts like bones and organs....
, development
Development

Development may refer to:...
, or behavior
Behavior

Behavior or behaviour refers to the action s or reactions of an object or organism, usually in Relational theory to the environment. Behavior can be conscious or Unconscious mind, overt or covert, and voluntary or involuntary....
. This distinction is fundamental in the study of inheritance of trait
Trait (biology)

A trait is a distinct variant of a phenotype character of an organism that may be inherited, environmentally determined or somewhere in between....
s and their evolution
Evolution

In biology, evolution is change in the heritability trait of a population of organisms from one generation to the next. These changes are caused by a combination of three main processes: variation, reproduction, and selection....
.

The genotype represents its exact genetic makeup — the particular set of gene
Gene

A gene is the basic unit of heredity in a living organism. All living things depend on genes. Genes hold the information to build and maintain their cell and pass genetic trait to offspring....
s it possesses. Two organisms whose genes differ at even one locus
Locus (genetics)

In the fields of genetics and evolutionary computation, a locus is a fixed position on a chromosome such as the position of a genetic marker that may be occupied by one or more genes....
 (position in their genome
Genome

In classical genetics, the genome of a diploid organism including eukarya refers to a full set of chromosomes or genes in a gamete; thereby, a regular somatic cell contains two full sets of genomes....
) are said to have different genotypes. The transmission of genes from parents to offspring is under the control of precise molecular mechanisms. The discovery of these mechanisms and their manifestations began with Mendel and comprises the field of genetics
Genetics

Genetics , a discipline of biology, is the science of heredity and Genetic variation in living organisms. The fact that living things inherit traits from their parents has been used since prehistoric times to improve crop plants and animals through selective breeding....
.

It is the organism's physical properties that directly determine its chances of survival and reproductive output, while the inheritance of physical properties occurs only as a secondary consequence of the inheritance of genes. Therefore, to properly understand the theory of evolution via natural selection
Natural selection

Natural selection is the process by which favorable heritable trait become more common in successive generations of a population of Reproduction organisms, and unfavorable heritable traits become less common, due to differential reproduction of genotypes....
, one must understand the genotype-phenotype distinction.

The mapping
Mapping

Mapping may refer to:*The making of maps, as in cartography, surveying, and photogrammetry;In biology and neuroscience:*Gene mapping, the assignment of DNA fragments to chromosomes...
 of a set of genotypes to a set of phenotypes is sometimes referred to as the genotype-phenotype map.

An organism's genotype is a major (the largest by far for morphology
Morphology (biology)

The term morphology in biology refers to form, structure and configuration of an organism. This includes aspects of the outward appearance as well as the form and structure of the internal parts like bones and organs....
) influencing factor in the development of its phenotype, but it is not the only one. Even two organisms with identical genotypes normally differ in their phenotypes. One experiences this in everyday life with monozygous (i.e. identical) twins. Identical twins share the same genotype, since their genomes are identical; but they never have the same phenotype, although their phenotypes may be very similar. This is apparent in the fact that their mothers and close friends can always tell them apart, even though others might not be able to see the subtle differences. Further, identical twins can be distinguished by their fingerprint
Fingerprint

A fingerprint is an impression of the friction ridges of all part of the finger. A friction ridge is a raised portion of the epidermis on the palmar or digits or plantar skin, consisting of one or more connected ridge units of friction ridge skin....
s, which are never completely identical.

The concept of phenotypic plasticity
Phenotypic plasticity

The ability of an organism with a given genotype to change its phenotype in response to changes in the environment is called phenotypic plasticity....
 describes the degree to which an organism's phenotype is determined by its genotype. A high level of plasticity means that environmental factor
Environmental factor

In epidemiology, environmental factors are those determinants of disease that are not transmitted genetics. Apart from the true Monogenic genetic disorders, environmental factors may determine the development of disease in those genetically predisposed to a particular condition....
s have a strong influence on the particular phenotype that develops. If there is little plasticity, the phenotype of an organism can be reliably predicted from knowledge of the genotype, regardless of environment
Environment (biophysical)

The biophysical environment is the symbiosis between the physics environment and the biological life forms within the environment, and include all variables that comprise the Earth's biosphere....
al peculiarities during development. An example of high plasticity can be observed in larva
Larva

A larva is a young form of animal with indirect developmental biology, going through or undergoing metamorphosis .The larva can look completely different from the adult form, for example, a caterpillar differs from a butterfly....
l newt
Newt

A newt is a salamander that lives in the water as an adult. Newts occur in the Pleurodelinae subfamily , found in North America, Europe and Asia....
s1: when these larvae sense the presence of predators such as dragonflies
Dragonfly

A dragonfly is a type of insect belonging to the order Odonata, the suborder Epiprocta or, in the strict sense, the infraorder Anisoptera....
, they develop larger heads and tails relative to their body size and display darker pigmentation. Larvae with these traits have a higher chance of survival
Survival skills

Survival skills are techniques a person may utilize for an indefinite duration in order to survive a dangerous situation . Generally speaking, these techniques are meant to provide the basic human needs for human life: fire, water, food, shelter, habitat, AND the needs to think straight, to signal for help, to navigate safely'...
 when exposed to the predators, but grow more slowly than other phenotypes.

In contrast to phenotypic plasticity, the concept of genetic canalization
Canalisation (genetics)

Canalisation is a measure of the ability of a population to produce the same phenotype regardless of variability of its environment or genotype....
 addresses the extent to which an organism's phenotype allows conclusions about its genotype. A phenotype is said to be canalized if mutation
Mutation

In biology, mutations are changes to the nucleotide sequence of the genetic material of an organism. Mutations can be caused by copying errors in the genetic material during cell division, by exposure to ultraviolet or ionizing radiation, chemical mutagens, or virus , or can be induced by the organism, itself, by cellular processes such as s...
s (changes in the genome) do not noticeably affect the physical properties of the organism. This means that a canalized phenotype may form from a large variety of different genotypes, in which case it is not possible to exactly predict the genotype from knowledge of the phenotype (i.e. the genotype-phenotype map is not invertible). If canalization is not present, small changes in the genome have an immediate effect on the phenotype that develops.

The terms "genotype" and "phenotype" were created by Wilhelm Johannsen
Wilhelm Johannsen

Wilhelm Johannsen was a Denmark botanist, plant physiologist and geneticist. He was born in Copenhagen. While very young, he was apprenticed to a pharmacist and worked in Denmark and Germany beginning in 1872 until passing his pharmacist's exam in 1879....
 in 1911.

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