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A recessive phenotype can only be observed when the individual carries both the recessive alleles for the specific trait.
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∙ 14y ago
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∙ 11y agoalbinism - only apparent when the parents are each either albino or carriers, and the offspring inherits two recessive genes.
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∙ 10y agoIn standard Mendelian genetics the only way a recessive trait could be expressed id if it is a homozygous trait.
aa, for instance.
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∙ 6y agowhen the organism is a hybrid
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Two dominant alleles are expressed at the same time?
The alleles are not always both expressed.Take the simplest example, a case when there are only two alleles for a trait, R and r. When the organism is a heterozygote, meaning that it has both alleles with a genotype of Rr, only the phenotype carried by the dominant allele, the R, will be expressed. The dominant allele masks the phenotype of the recessive allele. A case in which only the dominant phenotype is expressed in a heterozygote is a case of complete dominance.*Cases where the dominant allele does not completely mask the recessive allele are cases of incomplete dominance and co-dominance.In incomplete dominance, the dominant allele has some effect on the recessive allele, but not a full effect. This results in a third phenotype in the population. Think red and white flowers leading to pink flowers.In co-dominance, the dominant allele has as much effect on the phenotype of the organism as the recessive allele. Think red and white flowers now leading to red and white streaked flowers.
Why is it difficult to determine the genotype of an organism that has a dominant phenotype?
NO, because a dominant phenotype could either be homozygous or a heterozygous.so unless you are sure about the genotype of parents we can't determine it...but we can determine the genotype of a person showing reccessive phenotype, as a recessive trait always expresses itself in a homozygous condition...
What is the difference between dominant and recessive gene?
There are no such things as dominant and recessive genes. There are only dominant and recessive alleles. Dominant alleles are parts of a gene that present its features over the recessive allele, which is the one that is always masked by the dominant allele. The recessive allele's trait only shows if both of the alleles in a trait are recessive.
What is the phenotype of an individual with one allele for dimples and one allele for no dimples?
a example of a gene
A recessive allele is represented by an letter?
Most of the time a recessive allele is expressed using lower case letters in comparision to the upper case dominant alleles.
Two dominant alleles are expressed at the same time?
The alleles are not always both expressed.Take the simplest example, a case when there are only two alleles for a trait, R and r. When the organism is a heterozygote, meaning that it has both alleles with a genotype of Rr, only the phenotype carried by the dominant allele, the R, will be expressed. The dominant allele masks the phenotype of the recessive allele. A case in which only the dominant phenotype is expressed in a heterozygote is a case of complete dominance.*Cases where the dominant allele does not completely mask the recessive allele are cases of incomplete dominance and co-dominance.In incomplete dominance, the dominant allele has some effect on the recessive allele, but not a full effect. This results in a third phenotype in the population. Think red and white flowers leading to pink flowers.In co-dominance, the dominant allele has as much effect on the phenotype of the organism as the recessive allele. Think red and white flowers now leading to red and white streaked flowers.
Why is it difficult to determine the genotype of an organism that has a dominant phenotype?
NO, because a dominant phenotype could either be homozygous or a heterozygous.so unless you are sure about the genotype of parents we can't determine it...but we can determine the genotype of a person showing reccessive phenotype, as a recessive trait always expresses itself in a homozygous condition...
Why are recessive alleles not always expressed as the phenotype?
recessive alleles get masked to show the difference in a dominant gene and a recessive gene. the dominate genes masks the recessive genes to show that the dominate gene is more dominate or more likely to be the outcome than the reccessive gene but the masked gene is not always recessive.
What is the difference between dominant and recessive gene?
There are no such things as dominant and recessive genes. There are only dominant and recessive alleles. Dominant alleles are parts of a gene that present its features over the recessive allele, which is the one that is always masked by the dominant allele. The recessive allele's trait only shows if both of the alleles in a trait are recessive.
What if your uncle has hazel eyes and your other uncle has gray eyes and you have brown eyes can you carry both recessive traits hazel eyes and gray eyes at the same time?
You can only carry one recessive trait.
What is co - dominance?
Incomplete dominance is when both the dominant gene and recessive gene are present in an organism's phenotype. For example, since brown eyes are dominant and blue eyes are recessive in humans, a person who has incomplete dominance of eye color would have gray or green eyes; a mixture of both brown and blue. Codominance is when two dominant alleles are present at the same time. These two terms are not the same!
What is Incomplete co dominance?
Incomplete dominance is when both the dominant gene and recessive gene are present in an organism's phenotype. For example, since brown eyes are dominant and blue eyes are recessive in humans, a person who has incomplete dominance of eye color would have gray or green eyes; a mixture of both brown and blue. Codominance is when two dominant alleles are present at the same time. These two terms are not the same!
How do you get the genotype of the phenotype?
In order to determine the phenotype of the original organism observe any physical traits / characteristics Lookup the following concepts: punnet square, homozygous recessive/dominant. Draw the punnet square Determine the crossing Determine the dominant traits Determine the phenotype
What is the phenotype of an individual with one allele for dimples and one allele for no dimples?
a example of a gene
Which planets have not yet been observed?
Only the World Headquarters of Astronomy has that information, and it is closely guarded. Each name is to be announced on the day when it is scheduled to be observed for the first time, and then we will know which ones they are.
What Christian holiday is observed around the same time as Passover?
Easter is observed around the same time as Passover.
Are dominant or recessive alleles easier to remove by selection?
Natural selection favors whatever allele provides a selective advantage, so in theory it can operate on either. However, if a recessive allele provides an advantage it will soon shift and become the dominant allele, so it could be argued that natural selection favors dominant alleles. This is only partly true. A dominant gene always has some effect on the characteristics of the organism, even if the owner only has one of them. A recessive gene only affects the characteristics if there is no equivalent dominant gene to mask the effect. If both parents possess the recessive gene there is a chance the offspring will have two of them and this will show in their characteristics. When this happens, natural selection operates on the recessive gene. Much of the time, a recessive gene is present but natural selection does not affect it because there is a dominant gene that masks the effect. If natural selection favours the recessive gene, the dominant gene will quite quickly disappear from the population. This does not make the recessive gene 'dominant' it's just tht there's no longer any competition. If selection favours the dominant gene however, the recessive gene can linger in the population for much longer, because even when it is present, it is not selected against for most of the time. That is why conditions like heamophilia survives for a long time in humans, and you suddenly discover a white deer after many years in a herd of brown deer.
