The alleles for brown eyes (B) are dominant, while those for blue eyes (b) are recessive. If Lesley’s mother has the genotype BB and her father has the genotype bb, what is Lesley’s genotype? What is her phenotype?
Leslie is Bb, she has brown eyes.
. If Lesley’s mother has the genotype BB and her father has the genotype bb, what is Lesley’s genotype? What is her phenotype?
To determine Lesley's genotype and phenotype, let's first understand the concept of dominant and recessive alleles.
In this scenario, the allele for brown eyes (B) is dominant, while the allele for blue eyes (b) is recessive. This means that if an individual has at least one brown eye allele (B), the brown eye trait will be expressed.
Lesley's mother has the genotype BB, which means she has two brown eye alleles (B). Her father, on the other hand, has the genotype bb, indicating he has two blue eye alleles (b).
Using basic rules of inheritance, each parent passes one allele to their offspring. Therefore, Lesley can inherit either a brown eye allele (B) from her mother or a blue eye allele (b) from her father.
Now let's determine Lesley's genotype and phenotype:
1. Genotype: Since her mother has the genotype BB and her father has the genotype bb, Lesley can only inherit a brown eye allele (B) from her mother, as her father cannot provide a brown eye allele. Therefore, Lesley's genotype will be Bb.
2. Phenotype: According to the dominance rule, the presence of a single brown eye allele (B) is sufficient to express the brown eye trait, overriding the influence of the recessive blue eye allele (b). Hence, Lesley's phenotype will be brown eyes.
In summary, Lesley's genotype is Bb (having one brown eye allele and one blue eye allele), while her phenotype is brown eyes.
To determine Lesley's genotype and phenotype, we need to understand how alleles for eye color are inherited.
Alleles are alternative forms of a gene, in this case, the gene for eye color. Each person inherits two copies of the gene, one from each parent. The dominant allele (B) for brown eyes is expressed if either one or both of the copies is brown. The recessive allele (b) for blue eyes is expressed only if both copies are blue.
Now, let's consider Lesley's parents. Her mother has the genotype BB, which means that both copies of her eye color gene are brown. Her father, on the other hand, has the genotype bb, meaning that both copies of his eye color gene are blue.
Since Lesley's mother has two brown alleles, she can only give Lesley a brown allele. On the other hand, Lesley's father can only give her a blue allele. Therefore, Lesley's genotype would be Bb, as she has inherited a brown allele from her mother (B) and a blue allele from her father (b).
Lesley's phenotype, or her observable characteristic, would be brown eyes because the brown allele (B) is dominant over the blue allele (b). Even though she has a blue allele as well, the presence of just one brown allele is sufficient to produce the brown eye color.
So, Lesley's genotype is Bb, and her phenotype is brown eyes.