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If the phenotype is recessive then the genotype must be dd.
The genotype each offspring has is determined by the parents. They can be both homozygous dominant or are they heterozygous and homozygous(dominant or recessive)
A recessive phenotype is expressed in an offspring that has a homozygous recessive genotype for that trait.
No. Parents with the dominant phenotype might be heterozygous in their genotype. This means they could carry both the dominant and recessive allele for a trait. So they could both pass the recessive allele to an offspring, who would then have the homozygous recessive genotype and recessive phenotype.
For a dominant trait to be expressed, you either need a RR or an Rr genotype. The other genotype, rr, is recessive only. In genetics, capital letters represent a dominant allele, and lower case letters represent the recessive allele.
If the phenotype is recessive then the genotype must be dd.
The genotype each offspring has is determined by the parents. They can be both homozygous dominant or are they heterozygous and homozygous(dominant or recessive)
A recessive phenotype is expressed in an offspring that has a homozygous recessive genotype for that trait.
No. Parents with the dominant phenotype might be heterozygous in their genotype. This means they could carry both the dominant and recessive allele for a trait. So they could both pass the recessive allele to an offspring, who would then have the homozygous recessive genotype and recessive phenotype.
If both parents have the same phenotype, but the offspring did not share that phenotype, then it is likely that the parents have a dominant phenotype, but the offspring has a recessive phenotype, which means that the offpring's genotype would be homozygous recessive, and it's parents' genotypes would be heterozygous. For example, the parents may both have the genotype Bb, which gives them black fur. Approximately 25% of their offspring should have the genotype bb, which gives them the phenotype of white fur.
Genotype is the coded for traitPhenotype is the visible characteristicSo in the case where both parents had heterozygous dominant Brown eyes (Bb - big B for brown, dominant gene; little b for blue recessive gene); it is possible for the child to have blue eyes, by being homozygous recessive (bb).However this is an educated guess, as your question does not make sense.
For a dominant trait to be expressed, you either need a RR or an Rr genotype. The other genotype, rr, is recessive only. In genetics, capital letters represent a dominant allele, and lower case letters represent the recessive allele.
If both parents have the same phenotype, but the offspring did not share that phenotype, then it is likely that the parents have a dominant phenotype, but the offspring has a recessive phenotype, which means that the offpring's genotype would be homozygous recessive, and it's parents' genotypes would be heterozygous. For example, the parents may both have the genotype Bb, which gives them black fur. Approximately 25% of their offspring should have the genotype bb, which gives them the phenotype of white fur.
There is dominant and there is recessive. There is no dominant recessive. A dominant gene will always be expressed when present, such as in the homozygous dominant genotype (RR), or heterozygous genotype (Rr). A recessive allele is only expressed when the genotype is homozygous recessive (rr).
dominant allele before a recessive trait
If the recessive genotype is selected for more often than the dominant genotype, the recessive allele will become more common than the dominant allele in the gene pool.
A cross between a plant of unknown genotype and one that is known to be homozygous recessive is called a test cross because the recessive homozygote testswhether there are any recessive alleles in the unknown. Because the recessive homozygote will contribute an allele for the recessive characteristic to each offspring, the second allele (from the unknown genotype) will determine the offspring's phenotype.