Difference Between Monohybrid Cross and Dihybrid Cross

Main Difference – Monohybrid Cross vs Dihybrid Cross

Monohybrid cross and dihybrid cross are two genetic crossing methods that are used to study the inheritance of allele pairs. These are useful in understanding the inheritance of traits from one generation to another. Monohybrid cross is a genetic cross that involves a single pair of genes that is responsible for one trait. In a monohybrid cross, parents differ by a single trait. Dihybrid cross is a genetic cross that involves two pairs of genes which are responsible for two traits. In a dihybrid cross, parents have two different independent traits. The key difference between monohybrid cross and dihybrid cross is that in a monohybrid cross, inheritance of one trait (e.g.: height) is studied while in a dihybrid cross, inheritance of two independent traits (e.g.: flower colour, stem length) is studied.

Key Areas Covered

1. What is a Monohybrid Cross 
     – Definition, Traits, Process
2. What is a Dihybrid Cross
     – Definition, Traits, Process
3. What are the Similarities Between Monohybrid Cross and Dihybrid Cross
     – Outline of Common Features
4. What is the Difference Between Monohybrid Cross and Dihybrid Cross
    – Comparison of Key Differences

Key Terms: Allele, Dihybrid Cross, Genetic Cross, Inheritance, Monohybrid Cross, Single Trait Cross, Traits, Two Traits Cross

Difference Between Monohybrid Cross and Dihybrid Cross - Comparison Summary

What is a Monohybrid Cross?

A monohybrid cross is a genetic cross which occurs between two individuals, focusing on the inheritance of one trait at one time. Monohybrid cross is also known as single trait cross. Two homozygous parents are selected for this cross and studies are carried out about only one trait (for example, flower color), ignoring all other traits; thus, only a single gene pair is involved in this test method. This method is a crossbreeding of two true breeding parental lines. The following image explains the process of monohybrid crossing.

Main Difference - Monohybrid Cross vs Dihybrid Cross

Figure 01: Monohybrid Cross

One parent is homozygous for the dominant allele, and the other parent is homozygous for the recessive allele. The offspring is predicted and assessed for one trait inheritance in monohybrid cross. Therefore, the phenotypic ratio of the resulting offspring is 3:1 in monohybrid cross.

What is a Dihybrid Cross?

A dihybrid cross is a genetic cross that occurs between two individual, focusing on the inheritance of two independent traits at one time. Dihybrid cross is also known as two traits cross. The two parents considered for this cross have two independent traits (for example, pod color and pod shape in pea plants). Thus, a dihybrid cross involves two pairs of genes. The following figure explains the process of dihybrid crossing.

Difference Between Monohybrid Cross and Dihybrid Cross

Figure 02: Dihybrid Cross

In a dihybrid cross, traits are considered as not linked, and they have an equal probability of sharing up in offspring. Each pair of alleles segregates independently of the gametes. Offspring is predicted and assessed for two trait inheritance. The phenotypic ratio of the offspring generation is 9:3:3:1 in a dihybrid cross.

Similarities Between Monohybrid Cross and Dihybrid Cross

  • Genes are involved in both monohybrid cross and dihybrid cross.
  • Both crosses study how characteristics are transmitted to the offspring.
  • In both crosses, gene alleles are not considered as linked.

Difference Between Monohybrid Cross and Dihybrid Cross

Definition

Monohybrid Cross: A monohybrid cross is a genetic cross between homozygous individuals with different alleles for a single gene locus of interest.

Dihybrid Cross: A dihybrid cross is a genetic cross between individuals with different alleles for two gene loci of interest.

Number of Traits Considered

Monohybrid Cross: In a monohybrid cross, one character is considered and studied.

Dihybrid Cross: In a dihybrid cross, two independent characters are considered and studied.

Number of Gene Pairs 

Monohybrid Cross: In a monohybrid cross, a single pair of genes is involved.

Dihybrid Cross: In a dihybrid cross, two pairs of genes are involved.

Phenotypic Ratio of the Offspring

Monohybrid Cross: The predicted phenotypic ratio of a monohybrid cross is 3:1.

Dihybrid Cross: The predicted phenotypic ratio of dihybrid cross is 9:3:3:31.

Importance

Monohybrid Cross: Monohybrid cross is important for determining the dominance relationship of the alleles.

Dihybrid Cross: Dihybrid cross is important for assessing the independent assortment of alleles.

Conclusion

The main difference between monohybrid and dihybrid cross is the number of traits being studies in offspring. In a monohybrid cross, inheritance of a single trait is predicted. Parents of monohybrid crosses are different in one trait and are homozygous for the trait. In dihybrid crosses, inheritance of two traits is predicted. Parents of the dihybrid cross differ in two traits. If the alleles or the genes are not linked, the resulting phenotypic ratio of a monohybrid cross is 3:1 while in a dihybrid cross, it is 9:3:3:1.

Reference:

1. “Monohybrid cross.” Wikipedia, Wikimedia Foundation, 8 Jan. 2018, .
2. “Dihybrid cross.” Wikipedia, Wikimedia Foundation, 22 Oct. 2017, .
3. Bailey, Regina. “Monohybrid Cross: A Breeding Experiment.” ThoughtCo, .

Image Courtesy:

1. “Figure 12 02 02″ By – via
2. “Figure 12 03 02″ By – via

About the Author: admin

Leave a Reply


Related pages


message of the parable of the good samaritanwhat is the difference between food poisoning and the flucarcinoma and sarcoma differencedifference in monocots and dicotsacne pimple differencedifference between polar molecules and nonpolar moleculesis heavy cream the same as whipping creamwhy was percy bysshe shelley famousaliphatic compoundsdifference between health equity and equalitybeta plated sheetmeaning of enquiry and inquirystructuralism focuses onprimary and modal auxiliariesthe meaning of fleecedefine morphemesgluconeogenesis and glycolysisexample of indefinite pronoun singularwhat is the difference between a thesaurus and a dictionarydefine multicellularwhat is the relationship between a polymer and monomerdifference between prokaryotes and eukaryotes dna replicationproducer consumer surpluspreposition sincedifference between paraformaldehyde and formaldehydeprokaryotic transcription stepsstanza definition and examplewhat is thylakoidscientific classification of coriandercpi formularelation between mass and inertiatypical vs atypical antipsychoticschemical formula of deoxyribosecomparison between unicellular and multicellular organismshypoxemia versus hypoxiagerman measles rashexample of an indefinite pronoundifference between isotropic and anisotropicmacbeth foildifference between bipolar and borderline personality disordercomparison similecomedy of manners literary definitionwhat is hilumwhat is the difference between participle and gerundtyndall effect examplewhat is the difference between cougars and mountain lionsdifference of tortoise and turtledifference between preface and foreworddifference between prophase 1 and prophase 2elephants collective nounwarm blooded mammalsdifference between fibers and sclereidsduring endocytosis and exocytosis cellsmalamute husky differencedefine macronutrientpolar moment of inertia of a circlepackaging and packing differencefootnote apapolar and nonpolar solvents definitioncult vs religiondifference between husky and alaskan malamutewhat is in between the inner and outer planetsrough er and smooth er functionsfigurative vs literal languagealaskan huskies vs siberian huskiesdifferences between vitamins and mineralscharacteristics of c4 plantsdifference between edt and pstfructose definitionwhat is the difference between covalent bonds and ionic bondsbipolar and manic depression differencetest for sulfate ionthemes in charlottes webrhyme scheme limericksarcastic sardonicneutropenia leukopenia