when a trait is controlled by ____________ alleles, the gene exists in several allelic forms.


When A Trait Is Controlled By ____________ Alleles, The Gene Exists In Several Allelic Forms.?

when a trait is controlled by multiple alleles, the gene exists in several allelic forms. ABO blood types, results in more than two possible phenotypes for a particular trait. Down syndrome occurs because of an abnormality characterized by an extra copy of genetic material on all or part of the 21st chromosome.

When a trait exists in several allelic forms?

When there is a gene existing in more than two allelic forms, this condition is referred to as multiple allelism. Allelism refers to any of the several forms of a gene. These genetic variations arise usually through mutation and therefore are responsible for hereditary variations.

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How can multiple alleles provide many different phenotypes for a single trait?

Why can multiple alleles result in many different phenotypes for a trait? This can happen because the more allele options for a specific gene the more possible combinations and therefore possible phenotypes the organism that has that gene could inherit.

When a single gene locus has more than two possible alleles this is called?

Extensions of Mendel’s Ideas

The existence of more than one form of a particular phenotypic trait in a population is known as polymorphism. Polymorphism can derive from. multiple alleles at a single gene locus.

How many different combinations of alleles are possible among the gametes produced by an individual that is heterozygous for three separate genes?

Hints For Biology 101 Exam #4
Gametes ABC Abc
ABc 5 3
AbC 5 3
Abc 4 2
aBC 5 3

What is an example of multiple alleles trait What are the alleles that control the trait?

The majority of human genes are thought to have more than two normal versions or alleles. Traits controlled by a single gene with more than two alleles are called multiple allele traits. An example is ABO blood type.

Multiple Allele Traits.
Genotype Phenotype (blood type)
ii O

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.

Is controlled by three alleles ABO?

Human blood is controlled by three alleles that create the ABO blood types. A and B are co-dominant, while the third allele, O, is recessive to the other two alleles. Below are a number of parent combinations. For each, indicate whether it could produce the resulting child.

What are the alleles that control that 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.

When there are 2 alleles for a gene and both make a protein product the alleles are said to be?

Codominance is a relationship between two versions of a gene. Individuals receive one version of a gene, called an allele, from each parent.

When a single trait is controlled by more than one set of alleles it is referred to as a <UNK> trait?

Explanation: A trait that is controlled by more than one gene is called polygenic which translates to “multiple genes”. The genes work together to make one trait. Examples are skin, eye and hair color. Important.

When a single trait is affected by more than one gene locus this called quizlet?

A polygenic trait is one whose phenotype is influenced by more than one gene. Traits that display a continuous distribution, such as height or skin color, are polygenic.

When the alleles at one gene locus can mask the expression of alleles at another gene locus?

Rather, epistasis occurs in all of the following scenarios: Whenever two or more loci interact to create new phenotypes. Whenever an allele at one locus masks the effects of alleles at one or more other loci. Whenever an allele at one locus modifies the effects of alleles at one or more other loci.

What are the two alleles for this trait?

What are the two alleles of this trait? The two alleles of this trait are the P and F1 traits.

What type of allele will be expressed if both dominant and recessive alleles are present for a given trait?

A dominant phenotype will be expressed when at least one allele of its associated type is present, whereas a recessive phenotype will only be expressed when both alleles are of its associated type. However, there are exceptions to the way heterozygotes express themselves in the phenotype.

Which is dominant allele A or B?

With eye color, for instance, “B” stands for a brown allele and “b” stands for a blue allele. An organism with two dominant alleles for a trait is said to have a homozygous dominant genotype. Using the eye color example, this genotype is written BB.

Which of these traits is controlled by a gene with multiple alleles quizlet?

A trait controlled by one gene but multiple alleles is blood type. There are 4 phenotypes: A, B, AB, O. Types A and B are codominant, and O is recessive to A and B.

Which of the following is controlled by multiple alleles in humans?

The best characterized example of multiple alleles in humans is the ABO blood groups, discussed in the Non-Mendelian Inheritance concept. Other human traits determined by multiple alleles would be hair color, hair texture, eye color, built, physical structures, etc.

Which of the following traits is controlled by multiple alleles in human genetics?

Traits controlled by a single gene with more than two alleles are called multiple allele traits. An example is ABO blood type. Your blood type refers to which of certain proteins called antigens are found on your red blood cells.

Multiple Allele Traits.
Genotype Phenotype (blood type)
ii O
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Why does an individual always have only two alleles for a given gene?

Since diploid organisms have two copies of each chromosome, they have two of each gene. Since genes come in more than one version, an organism can have two of the same alleles of a gene, or two different alleles. This is important because alleles can be dominant, recessive, or codominant to each other.

What traits are likely to be controlled by multiple genes?

Polygenic inheritance occurs when one characteristic is controlled by two or more genes. Often the genes are large in quantity but small in effect. Examples of human polygenic inheritance are height, skin color, eye color and weight. Polygenes exist in other organisms, as well.

When two alleles express equally in a heterozygous individual then the following is true?

When two alleles express equally in a heterozygous individual then the following is true: One allele is not completely dominant over the other.

Which trait is normally controlled by multiple alleles but not multiple genes?

Which Trait Is Normally Controlled By Multiple Alleles But Not Multiple Genes? The ABO blood group in humans is a trait controlled by a single ABO gene with three types of alleles (multiple alleles) are seen.

How many alleles exist for a given gene quizlet?

Only two alleles can exist per gene. Four alleles exist per gene, two from each parent.

What are the three alleles responsible for ABO blood system?

The ABO locus has three main allelic forms: A, B, and O. The A and B alleles each encode a glycosyltransferase that catalyzes the final step in the synthesis of the A and B antigen, respectively.

What is an allele in genetics?

An allele is a variant form of a gene. … Humans are called diploid organisms because they have two alleles at each genetic locus, with one allele inherited from each parent. Each pair of alleles represents the genotype of a specific gene.

What is an allele quizlet?

An allele is an alternative form of a gene (one member of a pair) that is located at a specific position on a specific chromosome. These DNA codings determine distinct traits that can be passed on from parents to offspring.

How does an allele cause a trait in an organism?

Although an individual gene may code for a specific physical trait, that gene can exist in different forms, or alleles. One allele for every gene in an organism is inherited from each of that organism’s parents. … Alleles produce phenotypes (or physical versions of a trait) that are either dominant or recessive.

Are both alleles of a gene expressed?

The two chromosomal copies (alleles) of a gene are designated A and a. In most cases, both alleles are transcribed; this is known as bi-allelic expression (left). However, a minority of genes show monoallelic expression (right). In these cases, only one allele of a gene is expressed (right).

When both alleles of a heterozygote are expressed that trait is described as?

Codominance describes the simultaneous expression of both of the alleles in the heterozygote. Although diploid organisms can only have two alleles for any given gene, it is common for more than two alleles of a gene to exist in a population.

When both the alleles of a gene express themselves in heterozygous condition the phenomenon is called?

Codominance is a heterozygous condition in which both alleles at a gene locus are fully expressed in the phenotype.

What does it mean when a trait is controlled by multiple alleles?

There are traits in humans and other organisms that have three or more different types of alleles (genes). When a trait has three or more distinct alleles, we refer to it as having multiple alleles inheritance. The human ABO blood type alleles/trait is an example of a trait with multiple alleles.

When a single trait is affected by more than 1 gene locus?

Pleiotropy. When a single gene affects the expression of more than one phenotypic character, the phenomenon is known as pleiotropy (from the Greek pleio meaning “more” and “trop, meaning “change”).

When a single trait is decided by a single gene?

Genetic disorders determined by a single gene (Mendelian disorders) are easiest to analyze and the most well understood. If expression of a trait requires only one copy of a gene (one allele), that trait is considered dominant.

Alleles and genes

Multiple Alleles (ABO Blood Types) and Punnett Squares

Dominant Alleles vs Recessive Alleles | Understanding Inheritance


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