If the phenotype is recessive then the genotype must be dd.
One parent is heterozygous dominant (a dominant and a recessive allele) while the other parent is homozygous recessive (two recessive alleles).
Their genotypes would have to be 'rr' (r=recessive) because if they have the recessive trait, their genotype must be completely recessive.
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.
A recessive phenotype is expressed in an offspring that has a homozygous recessive genotype for that trait.
The genotype AA represents a homozygous dominant genotype. The capital letter "A" represents the dominant allele, while the lowercase letter "a" would represent the recessive allele. If both dominant alleles are present in a genotype (homozygous dominant) then the phenotype is "A" phenotype. If one dominant allele and one recessive allele are present (heterozygous dominant) then the phenotype is "A". Finally, if both recessive alleles "a" are present (homozygous recessive) then the phenotype is "a". Therefore, the answer to your question is the genotype AA would result in an "A" phenotype because the genotype is homozygous dominant.
They produce TTGG, TTGg, TTgg, ttGG, ttGg, ttgg, TtGG, TtGg, Ttgg offspring. Phenotype ratios will be: 9 dominant phenotype for both traits 3 dominant phenotype for T and recessive phenotype for g. 3 dominant phenotype for G and recessive phenotype for t. 1 recessive phenotype/genotype for both traits.
A homozygous dominant genotype means that both alleles for a trait are dominant. A heterozygous genotype means that one allele is dominant and the other is recessive. A heterozygous genotype will express the dominant phenotype, not the recessive phenotype.
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.
A recessive phenotype is expressed in an offspring that has a homozygous recessive genotype for that trait.
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.
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.
The genotype AA represents a homozygous dominant genotype. The capital letter "A" represents the dominant allele, while the lowercase letter "a" would represent the recessive allele. If both dominant alleles are present in a genotype (homozygous dominant) then the phenotype is "A" phenotype. If one dominant allele and one recessive allele are present (heterozygous dominant) then the phenotype is "A". Finally, if both recessive alleles "a" are present (homozygous recessive) then the phenotype is "a". Therefore, the answer to your question is the genotype AA would result in an "A" phenotype because the genotype is homozygous dominant.
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.
They produce TTGG, TTGg, TTgg, ttGG, ttGg, ttgg, TtGG, TtGg, Ttgg offspring. Phenotype ratios will be: 9 dominant phenotype for both traits 3 dominant phenotype for T and recessive phenotype for g. 3 dominant phenotype for G and recessive phenotype for t. 1 recessive phenotype/genotype for both traits.
homozygous recessive
They are traits that are passed on from parent to offspring. There are also two types of alleles; Dominant and recessive.
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.
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.
A homozygous dominant genotype means that both alleles for a trait are dominant. A heterozygous genotype means that one allele is dominant and the other is recessive. A heterozygous genotype will express the dominant phenotype, not the recessive phenotype.