A homozygous recessive allele combination contains two recessive alleles and expresses the recessive phenotype. … A homozygous plant contains either of the following alleles for seed shape: (RR) or (rr). The (RR) genotype is homozygous dominant and the (rr) genotype is homozygous recessive for seed shape.
What is an example of a homozygous recessive genotype?
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.
What does it mean if a genotype is homozygous recessive?
Homozygous means that the organism has two copies of the same allele for a gene. An organism can be homozygous dominant, if it carries two copies of the same dominant allele, or homozygous recessive, if it carries two copies of the same recessive allele.
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 the homozygous genotype?
(HOH-moh-ZY-gus JEE-noh-tipe) The presence of two identical alleles at a particular gene locus. A homozygous genotype may include two normal alleles or two alleles that have the same variant.
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.
What is meant by homozygous and heterozygous?
Homozygous: You inherit the same version of the gene from each parent, so you have two matching genes. Heterozygous: You inherit a different version of a gene from each parent.
What is a 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.
Which of the following 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.
Is homozygous AA or AA?
A homozygous genotype means that you have two of the same alleles, which are represented by the letters A or a. So if an individual has AA or aa, we say they are homozygous.
What are the 3 types of genotypes?
There are three types of genotypes: homozygous dominant, homozygous recessive, and hetrozygous.
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.