Finally, the genotype of an organism with two recessive alleles is called homozygous recessive. In the eye color example, this genotype is written bb. Of these three genotypes, only bb, the homozygous recessive genotype, will produce a phenotype of blue eyes.
Is TT homozygous recessive?
An organism can be either homozygous dominant ( TT ) or homozygous recessive ( tt ). If an organism has two different alleles ( Tt ) for a certain gene, it is known as heterozygous (hetero- means different).
What is an example of homozygous recessive?
For example, pea plants can have red flowers and either be homozygous dominant (red-red), or heterozygous (red-white). If they have white flowers, then they are homozygous recessive (white-white).
Is DD heterozygous or homozygous?
Sally’s genotype is “dd”, so she is also considered homozygous. Susan’s genotype is “Dd”, so she is considered HETEROZYGOUS (has two different alleles for a specific gene). Although Susan has both the allele “D” to make dimples and the allele “d” in her genotype, her phenotype is the presence of dimples.
What is an example of homozygous dominant genotype?
A homozygous dominant genotype is one in which both alleles are dominant. For example, in pea plants, height is governed by a single gene with two alleles, in which the tall allele (T) is dominant and the short allele (t) is recessive.
What is homozygous and heterozygous genotypes?
Heterozygous refers to having inherited different forms of a particular gene from each parent. A heterozygous genotype stands in contrast to a homozygous genotype, where an individual inherits identical forms of a particular gene from each parent.
What is heterozygous recessive example?
One such example is brown eyes (which is dominant) and blue eyes (which is recessive). If the alleles are heterozygous, the dominant allele would express itself over the recessive allele, resulting in brown eyes.
What is an example of a heterozygous genotype?
Together, these alleles are called a genotype. If the two versions are different, you have a heterozygous genotype for that gene. For example, being heterozygous for hair color could mean you have one allele for red hair and one allele for brown hair.
Is the genotype ee heterozygous or homozygous?
The person with the Ee genotype is heterozygous for the trait, in this case, free earlobes. An individual is heterozygous for a trait when it has two different allelic forms of a particular gene.
Is the genotype BB heterozygous or homozygous?
An organism with two dominant alleles for a trait is said to have a homozygous dominant genotype. Using the eye color example, this genotype is written BB. An organism with one dominant allele and one recessive allele is said to have a heterozygous genotype. In our example, this genotype is written Bb.
Is DD dominant or recessive?
You will have dimples if both copies are D (DD) or if only one is D (Dd). That is the definition of dominant. And of course, if both copies are d (dd), then you don’t have dimples.
What is an example of recessive genotype?
Only individuals with an aa genotype will express a recessive trait; therefore, offspring must receive one recessive allele from each parent to exhibit a recessive trait. One example of a recessive inherited trait is a smooth chin, as opposed to a dominant cleft chin. … Only (ss) individuals will express a smooth chin.
What is the recessive allele?
Recessive refers to a type of allele which will not be manifested in an individual unless both of the individual’s copies of that gene have that particular genotype.
What is recessive and dominant?
Dominant and recessive traits exist when a trait has two different forms at the gene level. The trait that first appears or is visibly expressed in the organism is called the dominant trait. The trait that is present at the gene level but is masked and does not show itself in the organism is called the recessive trait.