When two alleles that control a trait are the same?
An organism in which the two copies of the gene are identical — that is, have the same allele — is called homozygous for that gene. An organism which has two different alleles of the gene is called heterozygous.
What is it called when two or more genes affect the phenotype?
Any time two different genes contribute to a single phenotype and their effects are not merely additive, those genes are said to be epistatic.
What are the alleles that control the trait?
The combination of alleles that an organism carries constitutes its genotype. If the paired alleles are the same, the organism’s genotype is said to be homozygous for that trait; if they are different, the organism’s genotype is heterozygous.
What is it called when both alleles show up in the phenotype?
Codominance is a relationship between two versions of a gene. Individuals receive one version of a gene, called an allele, from each parent. … In codominance, however, neither allele is recessive and the phenotypes of both alleles are expressed.
When the phenotypes controlled by two alleles are equally displayed in the heterozygote the two alleles are said to show?
Codominance pertains to the genetic phenomenon in which gene products from the two alleles in a heterozygote are produced in roughly equal amount, where gene products refer to either different transcripts from the two alleles, different proteins from cellular processing of the transcripts, or different metabolites …
When the phenotypic expression of a character is controlled by two or more than two genes or alleles it is due to?
What is polygenic inheritance? Polygenic inheritance, in simple terms, implies a character or phenotypic trait, which is regulated by more than one gene. In biology, it refers to the quantitative inheritance wherein two or more independent genes additively affect a single phenotypic trait.
When there are 2 dominant alleles for the same gene?
If two alleles of a given gene are identical, the organism is called a homozygote and is said to be homozygous with respect to that gene; if instead the two alleles are different, the organism is a heterozygote and is heterozygous.
What is it called when one character is controlled by two different genes?
Inheritance. Polygenic inheritance occurs when one characteristic is controlled by two or more genes. … Examples of human polygenic inheritance are height, skin color, eye color and weight.
When one trait is governed by two or more sets of alleles this is called?
both homozygous dominant C. both heterozygous D. one homozygous dominant, one homozygous recessive 6 Page 7 30. When one trait is governed by two or more sets of alleles, this is called: … both parents are homozygous.
What happens to the phenotype of the heterozygotes when traits are inherited?
The relationship of genotype to phenotype is rarely as simple as the dominant and recessive patterns described by Mendel. … Mendel observed that a heterozygote offspring can show the same phenotype as the parent homozygote, so he concluded that there were some traits that dominated over other inherited traits.
When both alleles are expressed equally in the phenotype of the heterozygote?
Codominance occurs when both alleles are expressed equally in the phenotype of the heterozygote. The red and white flower in the figure has codominant alleles for red petals and white petals. Codominance.
When more than two alleles control the inheritance of a character?
A gene can have more than two alleles or allelomorphs, which can be expressed by mutation in wild form in more than one ways. These alleles or allelomorphs make a series of multiple alleles. The mode of inheritance in case of multiple alleles is called multiple allelism.
What occurs when two different dominant alleles are both fully expressed in the phenotype?
The correct answer: The two different dominant alleles are both fully expressed in the phenotype, are referred to as e. codominance.
When both alleles can be observed in a phenotype?
Codominance. Two alleles may be simultaneously expressed when both are present, rather than one fully determining the phenotype.
When the phenotypes produced by both alleles are completely expressed?
Biology: Chapter 11: Introduction to Genetics
|incomplete dominance||situation in which one allele is not completely dominant over another allele|
|codominance||situation in which the phenotypes produced by both alleles are completely expressed|
|multiple alleles||a gene that has more than two alleles|