Dominant and Recessive Alleles

Since the dominant allele (P) for purple flowers masks the expression of the recessive allele (p) for white flowers, all offspring will inherit one dominant allele (P) from the purple-flowered parent and one recessive allele (p) from the white-flowered parent, resulting in a heterozygous genotype (Pp). This genotype will express the dominant trait, which is purple flowers.

The heterozygous brown-eyed parent (Bb) can produce two types of gametes: B (carrying the dominant allele for brown eyes) and b (carrying the recessive allele for blue eyes). The homozygous blue-eyed parent (bb) can only produce one type of gamete: b (carrying the recessive allele for blue eyes). When these gametes combine, there is a 25% chance of inheriting two recessive alleles (bb), resulting in a blue-eyed child.

Since the dominant allele (R) for red flowers masks the expression of the recessive allele (r) for white flowers, all offspring will inherit one dominant allele (R) from the red-flowered parent and one recessive allele (r) from the white-flowered parent, resulting in a heterozygous genotype (Rr). This genotype will express the dominant trait, which is red flowers.

In a genetic cross, each parent contributes half of the genetic material to the offspring. Therefore, the genotype of an individual is determined by the alleles inherited from both parents.

A dominant allele is an allele that expresses its trait even when paired with a recessive allele. In the case of eye color, brown eyes are dominant over blue eyes. Therefore, brown eyes are an example of a dominant allele.

A recessive allele is an allele that only expresses its trait when paired with another identical recessive allele. In the case of eye color, blue eyes are recessive to brown eyes. Therefore, blue eyes are an example of a recessive allele.

The phenotype of an individual is determined by the interaction between the genotype of the individual and the environment in which the individual lives. Therefore, all of the above factors contribute to the phenotype of an individual.

A codominant allele is an allele that expresses its trait even when paired with a different allele. In the case of flower color, red flowers are codominant to white flowers. Therefore, red flowers are an example of a codominant allele.

An incomplete dominant allele is an allele that expresses its trait partially when paired with a different allele. In the case of flower color, pink flowers are incompletely dominant to white flowers. Therefore, pink flowers are an example of an incomplete dominant allele.

A polygenic trait is a trait that is controlled by multiple genes. Eye color, height, and skin color are all examples of polygenic traits. Therefore, all of the above are examples of polygenic traits.

A monogenic trait is a trait that is controlled by a single gene. Blood type is an example of a monogenic trait. Therefore, blood type is an example of a monogenic trait.

A sex-linked trait is a trait that is carried on the X or Y chromosome. Color blindness is an example of a sex-linked trait. Therefore, color blindness is an example of a sex-linked trait.

An autosomal trait is a trait that is carried on an autosome (a chromosome that is not a sex chromosome). Eye color is an example of an autosomal trait. Therefore, eye color is an example of an autosomal trait.

A homozygous genotype is a genotype that has two identical alleles for a particular gene. CC is an example of a homozygous genotype. Therefore, CC is an example of a homozygous genotype.

A heterozygous genotype is a genotype that has two different alleles for a particular gene. Aa is an example of a heterozygous genotype. Therefore, Aa is an example of a heterozygous genotype.