Type: Review
Pages: 3 | Words: 699
Reading Time: 3 Minutes

Polymorphism refers to the existence of genes of an organism into more than one form. There are various types of polymorphism, for example, genetic polymorphism, balanced polymorphism, and single nucleotide polymorphism. According to Fisher, polymorphism results from biodiversity and genetic variations amongst living organisms (25). For polymorphism to occur, the organisms must occupy the same habit and develop different types of genes.

A balanced polymorphism refers to a genetic condition in which a heterozygote that has two alleles of a particular type of gene develops an added advantage over a homozygote that has one type of allele. Fisher (7) defines a balanced polymorphism as a situation in which an equilibrium mixture of homozygote and heterozygote are maintained within an organism through natural selection against a homozygote. Balanced polymorphism has seen in wild animals such as the light-morph and dark-morph jaguars, human beings, and plants. In balanced polymorphism, the heterozygote maintains a stable equilibrium than the homozygote.

In my opinion, a balanced polymorphism refers to a condition whereby two or more different types of a gene or organisms exist within a given population as a result of the existence of varying versions of genes within the organisms. These different versions of a gene are called alleles. Usually, alleles are different form one another. Alleles often form sequences called nucleotides. The nucleotides are capable of changing the structure and function of the gene and hence may negatively or positively affect the characteristics of an organism such as body structure, appearance and ability to survive or adapt to the environment. The effects of alleles in an organism are usually affected by the environment in which the organism lives.

Illustration Using Sickle Cell Anemia and Malaria

Sickle cell anemia refers to a genetic disease that affects the ability of red blood cells to function properly. When a person is affected by sickle cell anemia, his or her red blood cells change shape and acquire the biconcave or sickle shape. This results into reduce ability of the red blood cells to effectively carry oxygen within the body. In my view, a person with sickle cells often suffers from anemia because the damaged red blood cells are removed from the bloodstream. This consequently leads to reduced number of red blood cells in the body, hence the name sickle cell anemia. It is believed that formation of the sickle cells in the blood is caused by genetic mutations of genes in the body. A person with copies of the defective hemoglobin gene or heterozygote is usually considered as carriers and suffers milder complications as compared to persons with the single recessive gene of the hemoglobin.

In human beings, those who have the sickle cell anemia may survive or not depending on the type of alleles they have developed. According to Fisher, individuals with two copies of the sickle cell allele that contain the hemoglobin rarely survive (162). The hemoglobin is responsible for carrying oxygen within the red blood cells. On the other hand, individuals with one copy of the sickle cell allele and a different copy of hemoglobin often survive into adulthood. This existence, usually referred to as heterozygote advantage, is also observed in persons who live in areas prone to malaria. In such places, such as tropical Africa and India, individuals with different combinations of the alleles have better capability to develop resistance to malaria than those with identical alleles. A good example of polymorphism is found in people living in tropical areas in Africa and certain regions of India. Individuals with recessive sickle cell hemoglobin would have shorted life expectancy as compared to persons with the normal sickle cell hemoglobin. As a result of this difference, person with the variant sickle cell hemoglobin often survive longer than the normal population because the variant sickle cells are resistant to malaria.

Another good example of balanced polymorphism is shown by liver cells. In the liver, a special set of enzymes that detoxify poisons may have different alleles in different organisms. This condition affects the ability of an organism to protect itself from poisons and other toxic chemicals. In this regard, organisms with more alleles for detoxification are better protected while those with fewer alleles for detoxification in their livers are less protected.

Copy-pasting equals plagiarizing!

Mind that anyone can use our samples, which may result in plagiarism. Want to maintain academic integrity? Order a tailored paper from our experts.

Get my custom paper
3 hours
the shortest deadline
original, no AI
300 words
1 page = 300 words
This is a sample essay that should not be submitted as an actual assignment
Need an essay with no plagiarism?
Grab your 15% discount
with code: writers15
Related essays
1 (888) 456 - 4855