Each pair of alleles represents the genotype of a specific gene. Genotypes are described as homozygous if there are two identical alleles at a particular locus and as heterozygous if the two alleles differ. Alleles contribute to the organism’s phenotype, which is the outward appearance of the organism.
- 1 Which both alleles contribute to the phenotype of the organism?
- 2 When both alleles in a nucleus are identical?
- 3 How many alleles influence the phenotype in?
- 4 When both alleles are expressed equally?
- 5 Are both alleles expressed?
- 6 When both alleles are expressed in the heterozygous state?
- 7 When both alleles are expressed equally in the phenotype of the heterozygote?
- 8 Where are the two alleles that make up a genotype located?
- 9 When both alleles are the same for a gene the condition is called?
- 10 What is the type of allele that only affects the phenotype in the homozygous condition?
- 11 What are the phenotypes of both A and B are dominant and O is recessive?
- 12 When both alleles are the same?
- 13 When two alleles are equally dominant they interact to produce a new phenotype?
- 14 Why does an individual always have only two alleles for a given gene?
- 15 What is two identical alleles for a given gene?
- 16 When both copies of a gene or chromosome are functional but only one is expressed This is an example of?
- 17 Is phenotype determined by genotype?
- 18 Do alleles make up genes?
- 19 What type of allele will be expressed if both dominant and recessive alleles are present for a given trait?
- 20 Where are alleles located on a chromosome?
- 21 What is source of the different alleles of the same gene?
- 22 What happens when you cross a heterozygous with a homozygous?
- 23 Are all alleles either completely dominant or completely recessive?
- 24 How would you describe the phenotype of a heterozygous A?
- 25 What happens if you have two different dominant alleles?
- 26 What type of inheritance do two alleles have their traits blend together?
- 27 How does the relationship between dominant and recessive alleles differ from epistasis?
- 28 Which type of dominance occurs when the heterozygote has the same phenotype as one of the homozygotes?
- 29 What are two alleles that control the phenotype of a trait?
- 30 When more than two alleles control the inheritance of a character?
- 31 Which allele is recessive and which alleles are codominant with regards to ABO blood grouping?
- 32 When both alleles are expressed equally in the phenotype of the heterozygotes?
- 33 When the heterozygous genotype results in a phenotype where both alleles are fully and separately?
- 34 Why do alleles occur in pairs?
- 35 How are genes and alleles related to genotype and phenotype?
- 36 Where are the two alleles that make up a genotype located?
- 37 Where the two alleles for a certain character are located?
- 38 When both alleles are expressed equally?
- 39 When homologous chromosomes have the same alleles on them?
- 40 Are both chromosomes expressed?
- 41 Is it possible for two alleles to produce four phenotypes?
- 42 How do you determine a phenotype?
- 43 What is the type of allele that only affects the phenotype in the homozygous condition?
- 44 What are the phenotypes of both A and B are dominant and O is recessive?
- 45 Why are some alleles dominant and others recessive?
- 46 What does a dominant allele do to a recessive allele?
- 47 What are alleles at the molecular level?
- 48 Are alleles on the same chromosome?
- 49 How does an allele different from a gene?
- 50 How are genes and alleles related?
Which both alleles contribute to the phenotype of the organism?
Both the A and B alleles contribute to the phenotype of the heterozygote. Thus the alleles A and B are said to be co-dominant.
When both alleles in a nucleus are identical?
Homozygous also refers to a genotype consisting of two identical alleles of a gene for a particular trait. An individual may be homozygous dominant (AA) or homozygous recessive (aa). Individuals who are homozygous for a trait are referred to as homozygotes.
How many alleles influence the phenotype in?
The number of possible phenotypes depends on the dominance relationships between the three alleles. Figure 8.15 Inheritance of the ABO blood system in humans is shown.
When both alleles are expressed equally?
If both alleles are dominant, it is called codominance?. The resulting characteristic is due to both alleles being expressed equally. An example of this is the blood group AB which is the result of codominance of the A and B dominant alleles.
Are both alleles 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 are expressed in the heterozygous state?
Co-dominance: A condition in which both alleles of a gene pair in a heterozygote are fully expressed, with neither one being dominant or recessive to the other. Codominance is a relationship between two versions of a gene.
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.
Where are the two alleles that make up a genotype located?
An allele is a variant form of a gene. Some genes have a variety of different forms, which are located at the same position, or genetic locus, on a chromosome. Humans are called diploid organisms because they have two alleles at each genetic locus, with one allele inherited from each parent.
When both alleles are the same for a gene the condition is called?
An organism in which the two copies of the gene are identical — that is, have the same allele — is called homozygous for that gene.
What is the type of allele that only affects the phenotype in the homozygous condition?
Recessive alleles only express their phenotype if an organism carries two identical copies of the recessive allele, meaning it is homozygous for the recessive allele. This means that the genotype of an organism with a dominant phenotype may be either homozygous or heterozygous for the dominant allele.
What are the phenotypes of both A and B are dominant and O is recessive?
People who are type O have OO genotypes. In other words, they inherited a recessive O allele from both parents. The A and B alleles are codominant. Therefore, if an A is inherited from one parent and a B from the other, the phenotype will be AB.
When both alleles are the same?
If the two alleles are the same, the individual is homozygous for that gene. If the alleles are different, the individual is heterozygous.
When two alleles are equally dominant they interact to produce a new phenotype?
Codominance is a relationship between two versions of a gene. Individuals receive one version of a gene, called an allele, from each parent. If the alleles are different, the dominant allele usually will be expressed, while the effect of the other allele, called recessive, is masked.
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 is two identical alleles for a given gene?
Listen to pronunciation. (HOH-moh-ZY-gus JEE-noh-tipe) The presence of two identical alleles at a particular gene locus. A homozygous genotype may include two normal alleles or two alleles that have the same variant.
When both copies of a gene or chromosome are functional but only one is expressed This is an example of?
Gene expression is termed “monoallelic” when only one of the two copies of a gene is active, while the other is silent.
Is phenotype determined by genotype?
A phenotype is an individual’s observable traits, such as height, eye color, and blood type. The genetic contribution to the phenotype is called the genotype. Some traits are largely determined by the genotype, while other traits are largely determined by environmental factors.
Do alleles make up genes?
A gene is a portion of DNA that determines a certain trait. An allele is a specific form of a gene. Genes are responsible for the expression of traits. Alleles are responsible for the variations in which a given trait can be expressed.
What type of allele will be expressed if both dominant and recessive alleles are present for a given trait?
Codominance. As opposed to partial dominance, codominance occurs when the phenotypes of both parents are simultaneously expressed in the same offspring organism.
Where are alleles located on a chromosome?
The allele contained on the homologous chromosome derived from the mother is termed the material allele. The allele located on the homologous chromosome derived from the father is termed the paternal allele. All diploid organisms have two alleles at a given locus on a pair of homologous chromosomes.
What is source of the different alleles of the same gene?
What is the original source of variation among the different alleles of a gene? Mutations in a gene lead to the different versions (alleles) of that gene.
What happens when you cross a heterozygous with a homozygous?
https://www.youtube.com/watch?v=D8Nu3Aw6F2A
Are all alleles either completely dominant or completely recessive?
In the real world, genes often come in many versions (alleles). Alleles aren’t always fully dominant or recessive to one another, but may instead display codominance or incomplete dominance.
How would you describe the phenotype of a heterozygous A?
Heterozygous individuals have a phenotype somewhere in the middle, what people might call “wavy” hair. In a heterozygous individual, only one curly allele is present, and only half the amount of protein can be made. This causes the hair to be about as half as curly as in a homozygous curly individual.
What happens if you have two different dominant alleles?
When you have two copies of the alleles that are both dominant, this is called codominance . For example, if the dominant trait is red for flowers and another dominant trait is white, then the flower will have both red and white as the dominant traits are expressed equally.
What type of inheritance do two alleles have their traits blend together?
Codominance. Codominance refers to the dominance in which the two alleles or traits of the genotypes (of both homozygotes) are expressed together in offspring (phenotype).
How does the relationship between dominant and recessive alleles differ from epistasis?
Dominant epistasis is when only one allele of the gene that shows epistasis can mask alleles of the other gene. Recessive epistasis is where two alleles have to be inherited in order for the phenotype of the second gene to be masked.
Which type of dominance occurs when the heterozygote has the same phenotype as one of the homozygotes?
Hence, the heterozygote (Aa) will have the same phenotype as that of the dominant homozygote (AA). This condition is called complete dominance.
What are two alleles that control the phenotype of a trait?
Dominant and Recessive Alleles
When the alleles of a pair are heterozygous, the phenotype of one trait may be dominant and the other recessive. The dominant allele is expressed and the recessive allele is masked. This is known as complete genetic dominance.
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.
Which allele is recessive and which alleles are codominant with regards to ABO blood grouping?
The ABO blood type is inherited in an autosomal codominant fashion. The A and B alleles are codominant, and the O allele is recessive.
When both alleles are expressed equally in the phenotype of the heterozygotes?
Codominance occurs when both alleles are expressed equally in the phenotype of the heterozygote.
When the heterozygous genotype results in a phenotype where both alleles are fully and separately?
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 for a gene to exist in a population.
Why do alleles occur in pairs?
Alleles can occur in pairs or multiple alleles affecting phenotype of a specific trait. As chromosomes occur in pairs for each characteristic, there are two possible alleles. The different versions of alleles occur as DNA base sequence varies.
Each pair of alleles represents the genotype of a specific gene. Genotypes are described as homozygous if there are two identical alleles at a particular locus and as heterozygous if the two alleles differ. Alleles contribute to the organism’s phenotype, which is the outward appearance of the organism.
Where are the two alleles that make up a genotype located?
Humans are diploid organisms, which means that they have two alleles at each genetic position, or locus, with one allele inherited from each parent. Each pair of alleles represents the genotype of a specific gene.
Where the two alleles for a certain character are located?
Each allele occupies a specific region on the chromosome called a gene locus. The gene’s two alleles are located in the same region in two homologous chromosomes, one inherited from each parent. The alleles may be dominant or recessive.
When both alleles are expressed equally?
If both alleles are dominant, it is called codominance?. The resulting characteristic is due to both alleles being expressed equally. An example of this is the blood group AB which is the result of codominance of the A and B dominant alleles.
When homologous chromosomes have the same alleles on them?
Diploid organisms, for example, humans, have paired homologous chromosomes in their somatic cells, and these contain two copies of each gene. An organism in which the two copies of the gene are identical — that is, have the same allele — is called homozygous for that gene.
Are both chromosomes expressed?
Diploid organisms bear two homologous copies of each chromosome (one from each parent), a gene can be expressed from both chromosomes (biallelic expression) or from only one (monoallelic expression).
Is it possible for two alleles to produce four phenotypes?
Is it possible for two alleles to produce four phenotypes? No, it is not possible. How many alleles are there for blood type? There are three alleles that produce only four phenotypes.
How do you determine a phenotype?
https://www.youtube.com/watch?v=69Hv7YIUVQg
What is the type of allele that only affects the phenotype in the homozygous condition?
Recessive alleles only express their phenotype if an organism carries two identical copies of the recessive allele, meaning it is homozygous for the recessive allele. This means that the genotype of an organism with a dominant phenotype may be either homozygous or heterozygous for the dominant allele.
What are the phenotypes of both A and B are dominant and O is recessive?
People who are type O have OO genotypes. In other words, they inherited a recessive O allele from both parents. The A and B alleles are codominant. Therefore, if an A is inherited from one parent and a B from the other, the phenotype will be AB.
Why are some alleles dominant and others recessive?
The two alleles for a gene don’t need to be the same. The instructions you get from your mom can be a little different from the instructions you get from your dad. And these different instructions — or alleles — will end up making slightly different proteins. This is where dominant and recessive come from.
What does a dominant allele do to a recessive allele?
A dominant allele produces a dominant phenotype in individuals who have one copy of the allele, which can come from just one parent. For a recessive allele to produce a recessive phenotype, the individual must have two copies, one from each parent.
What are alleles at the molecular level?
An allele is a variation of the same sequence of nucleotides that encodes the synthesis of a gene product at the same place on a long DNA molecule. At the lowest extreme, an allele can be based on a single nucleotide polymorphism (SNP).
Are alleles on the same chromosome?
Humans have 23 chromosome pairs, or 46 chromosomes in all. Homologous chromosomes have the same genes arranged in the same order, but they have slightly different DNA sequences. Different versions of the same gene are called alleles (uh-LEELZ); homologous chromosomes often contain different alleles.
How does an allele different from a gene?
A gene is a unit of hereditary information. Except in some viruses, genes are made up of DNA, a complex molecule that codes genetic information for the transmission of inherited traits. Alleles are also genetic sequences, and they too code for the transmission of traits.
A gene is a portion of DNA that determines a certain trait. An allele is a specific form of a gene. Genes are responsible for the expression of traits. Alleles are responsible for the variations in which a given trait can be expressed.