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What is the ONLY genotype that can produce a recessive phenotype?
Wiki User
∙ 8y ago
Only a homozygous recessive individual will have the phenotype created by two recessive alleles.
Since the term produce might indicate the production of offspring parents that can only produce offspring with a recessive phenotype must both have homozygous recessive genotypes.
Wiki User
∙ 8y ago
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To produce pea plat that only display the recessive phenitypw of a trait what must be the genotypes of the parent plats?
To produce a pea plant that only displays the recessive phenotype both of the parents must also have the recessive phenotype. In a four square, if one parent displays the recessive phenotype while the other has the dominant phenotype, one of every four offspring should theoretically receive the recessive phenotype as well, but if you want all offspring to be recessive, both parents must also be recessive. (tt)
What phenotype does an individual with a homozygous recessive genotype exhibit?
For what trait? Phenotype means the way in which a gene is expressed ie hair colour, kidney function, ear shape. Homozygous means that both genes for that trait are the same. A recessive gene is one that would not be the phenotype if there was a dominant gene paired with it. So the individual has genes for a trait that are the same, and thus expressed, but they wouldn't be if they had only one of that gene.
How do geneticists normally tell whether an organism exhibiting a dominant phenotype is homozygous or heterozygous?
They perform a test cross. A test cross takes the unknown genotype and crosses it with a known homozygous recessive. If the F1 generation is all dominant, then they know the organism was a homozygous recessive. If recessive offspring appear, then the organism was a heterozygote. As an example, consider a gene with two alleles, A and a, with Adominant. Now consider the test cross. The unknown genotype can only be one of two possibilities: AA (homozgous dominant) Aa (heterozygous) In a test cross,the unknown genotype is crossed with a known homozygous recessive. Since there are only two possible unknown genotypes, there can be only two possible results. First, consider the case of the unknown genotype being a homozygous dominant. The cross looks like this: AA X aa Remember that a homozygote for an allele can only produce one kind of gamete. In this case the homozygous dominant can only produce gametes with the allele A in them, while the homozygous recessive can only produce gametes with the recessive allele a in them. This means the F1 offspring can only be ONE genotype; Aa. Therefore, all of the offspring would have the dominant phenotype. Now consider the other possible cross, where the unknown genotype is heterozygous: AaX aa Remember that a heterozygote can produce two types of gametes. In this case, the unknown would produce gametes with the dominant allele A or the recessive allele a. The homozygous recessive would still only produce one kind gamete, with the recessive a allele. Therefore, we expect to see only two genotypes in the F1, Aa and aa, in equal proportions. In either case, only one test cross is needed to tell one immediately the nature of the unknown genotype. If all of the F1 are of the dominant phenotype, then the unknown genotype must be homozygous dominant; if a mixture of phenotypes appears in equal proportion, then the unknown genotype must be a heterozygote.
Why is it not necessary when the dominant and recessive traits are known to use the term homozygous when referring to the genotype of an individual that has a recessive phenotype?
An organism with a recessive allele from a particular form of a trait will exhibit that form only when the dominant allele for the trait is not present.
Can you determine a persons genotype based on phenotype?
In some cases but not others. Certain alleles can be dominant, which means that they will dictate the phenotype should there be a clash of alleles in the genotype. Other alleles can be recessive, which means you'd need both of these alleles in these genotype in order for it to dictate the phenotype. This means that if a person's phenotype represents a dominant trait, we cannot be certain what their genotype is. If, however, it represents a recessive trait, we know that their genotype must be the recessive allele twice.
Using the terms dominant recessive explain the difference between genotype and phenotype?
No, I think you have your terms confused.The terms "dominant" and "recessive" are applied to alleles of a genotype. A genotype is an expression (using upper- and lower-case letters) that shows what alleles an organism has for a particular locus. The two alleles (in most cases) inherited (one from mother and one from father) can either be dominant or recessive. The recessive allele is not fully expressed in the presence of the dominant allele and is only expressed when there are two recessive alleles. The genotype could be called "recessive" I suppose if the genotype is homozygous recessive. But remember that two recessive alleles as a genotype is only one possibility - in which case you can't say the "genotype is recessive".The phenotype is dependent on the genotype. If present, the dominant alleles (in simple Mendelian genetics) will determine the phenotype - what the organism's trait or characteristic is. The phenotype will never be what is coded by the recessive allele unless the genotype is two recessive alleles.
How are Genotype phenotype different?
Phenotypes are the traits expressed by the genotype. So, for blood type, a person can have A and i alleles (genotype). However, in the phenotype, since i is recessive, only the A will be expressed, and the person will have an A blood type.
To produce pea plants that only display recessive phenotype of a trait what must be the genotype of the parent plant?
both must be tt or both must be Tt
To produce pea plants that only display recessive Phenotype of a trait what must be the genotype of the parents plants?
both must be tt or both must be Tt
What is recessive gene and dominant gene?
A dominant gene is always expressed if present, and the recessive gene is only expressed with the homozygous recessive genotype. For example, if the dominant gene is red (represented by the letter R) and the recessive gene is white (represented by the letter r), then a homozygous dominant organism's genotype will be RR, and its phenotype will be red. If the organism is homozygous recessive, then the genotype will be rr and the phenotype will be white. If the organism is heterozygous, then the genotype will be Rr, and the organism will be red.
To produce pea plat that only display the recessive phenitypw of a trait what must be the genotypes of the parent plats?
To produce a pea plant that only displays the recessive phenotype both of the parents must also have the recessive phenotype. In a four square, if one parent displays the recessive phenotype while the other has the dominant phenotype, one of every four offspring should theoretically receive the recessive phenotype as well, but if you want all offspring to be recessive, both parents must also be recessive. (tt)
What phenotype does an individual with a homozygous recessive genotype exhibit?
For what trait? Phenotype means the way in which a gene is expressed ie hair colour, kidney function, ear shape. Homozygous means that both genes for that trait are the same. A recessive gene is one that would not be the phenotype if there was a dominant gene paired with it. So the individual has genes for a trait that are the same, and thus expressed, but they wouldn't be if they had only one of that gene.
How do geneticists normally tell whether an organism exhibiting a dominant phenotype is homozygous or heterozygous?
They perform a test cross. A test cross takes the unknown genotype and crosses it with a known homozygous recessive. If the F1 generation is all dominant, then they know the organism was a homozygous recessive. If recessive offspring appear, then the organism was a heterozygote. As an example, consider a gene with two alleles, A and a, with Adominant. Now consider the test cross. The unknown genotype can only be one of two possibilities: AA (homozgous dominant) Aa (heterozygous) In a test cross,the unknown genotype is crossed with a known homozygous recessive. Since there are only two possible unknown genotypes, there can be only two possible results. First, consider the case of the unknown genotype being a homozygous dominant. The cross looks like this: AA X aa Remember that a homozygote for an allele can only produce one kind of gamete. In this case the homozygous dominant can only produce gametes with the allele A in them, while the homozygous recessive can only produce gametes with the recessive allele a in them. This means the F1 offspring can only be ONE genotype; Aa. Therefore, all of the offspring would have the dominant phenotype. Now consider the other possible cross, where the unknown genotype is heterozygous: AaX aa Remember that a heterozygote can produce two types of gametes. In this case, the unknown would produce gametes with the dominant allele A or the recessive allele a. The homozygous recessive would still only produce one kind gamete, with the recessive a allele. Therefore, we expect to see only two genotypes in the F1, Aa and aa, in equal proportions. In either case, only one test cross is needed to tell one immediately the nature of the unknown genotype. If all of the F1 are of the dominant phenotype, then the unknown genotype must be homozygous dominant; if a mixture of phenotypes appears in equal proportion, then the unknown genotype must be a heterozygote.
If an organism expresses a recessive phenotype can you tell its genotype?
Yes because if the phenotype is recessive there is only one possible genotype, little letter little letter ex. rr (wrikled pea plant seed), cc (albino), tt (short pea plant) whereas if you have a dominante phenotype there are two possible genotypes, big letter big letter or big letter little letter ex. RR Rr (round pea plant seed), CC Cc (normal skin pigmentation) TT Tt (Tall Pea plant)
Why is it not necessary when the dominant and recessive traits are known to use the term homozygous when referring to the genotype of an individual that has a recessive phenotype?
An organism with a recessive allele from a particular form of a trait will exhibit that form only when the dominant allele for the trait is not present.
Can you determine a persons genotype based on phenotype?
In some cases but not others. Certain alleles can be dominant, which means that they will dictate the phenotype should there be a clash of alleles in the genotype. Other alleles can be recessive, which means you'd need both of these alleles in these genotype in order for it to dictate the phenotype. This means that if a person's phenotype represents a dominant trait, we cannot be certain what their genotype is. If, however, it represents a recessive trait, we know that their genotype must be the recessive allele twice.
How differences in genotypes cause variations in phenotypes?
Phenotypes are the traits expressed by the genotype. So, for blood type, a person can have A and i alleles (genotype). However, in the phenotype, since i is recessive, only the A will be expressed, and the person will have an A blood type.
