A homozygous recessive allele combination contains two recessive alleles and expresses the recessive phenotype. For example, the gene for seed shape in pea plants exists in two forms, one form (or allele) for round seed shape (R) and the other for wrinkled seed shape (r).
What are homozygous recessive examples?
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). Carriers are always heterozygous. People with CF are homozygous recessive.
What is an example of homozygous dominant and homozygous recessive?
A full head of hair is a dominant feature, with the homozygous gene of HH. However, the recessive trait – baldness – can be manifested in an individual with the homozygous recessive gene, or hh. Curly hair is a dominant trait, with the homozygous HH gene causing the condition.
What is a homozygous dominant example?
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’s a homozygous recessive trait?
Homozygous recessive is a term used to describe an organism that carries two identical copies of the recessive gene. Explore the definition of homozygous recessive along with examples of genetic disorders that occur as a result of this gene.
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 heterozygous example?
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. The relationship between the two alleles affects which traits are expressed.
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 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.
What is recessive and dominant?
Dominant refers to the relationship between two versions of a gene. Individuals receive two versions of each gene, known as alleles, from each parent. If the alleles of a gene are different, one allele will be expressed; it is the dominant gene. The effect of the other allele, called recessive, is masked.
Is FF dominant or recessive?
Typically one allele is dominant. That means that it shows up in the phenotype whether you have one copy of it, or two copies. A Recessive allele only has an effect if you inherit two copies eg ff (cystic fibrosis).
|f f||Homozygous recessive||Cystic fibrosis (has symptoms)|
What is a homozygous gene?
(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 example of phenotype?
The term “phenotype” refers to the observable physical properties of an organism; these include the organism’s appearance, development, and behavior. … Examples of phenotypes include height, wing length, and hair color.