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. Finally, the genotype of an organism with two recessive alleles is called homozygous recessive.
Is homozygous dominant or 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 heterozygous a recessive trait?
When you’re heterozygous for a specific gene, it means you have two different versions of that gene. The dominant form can completely mask the recessive one, or they can blend together. In some cases, both versions appear at the same time.
Is a homozygous trait?
When a particular gene has identical alleles (versions) of chromosomes inherited from both parents, the gene is homozygous. A homozygous trait is referred to by two capital letters (XX) for a dominant trait, and two lowercase letters (xx) for a recessive trait.
What trait is recessive?
Refers to a trait that is expressed only when genotype is homozygous; a trait that tends to be masked by other inherited traits, yet persists in a population among heterozygous genotypes.
What are homozygous and heterozygous traits?
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. They do not match.
Is homozygous recessive genotype or phenotype?
A homozygous dominant allele combination contains two dominant alleles and expresses the dominant phenotype (expressed physical trait). A homozygous recessive allele combination contains two recessive alleles and expresses the recessive phenotype.
Which trait is homozygous dominant?
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 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 a heterozygous trait?
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.
Which is 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.
Which pair of alleles represents a recessive trait?
Recessive alleles are denoted by a lowercase letter (a versus A). 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.
What is homozygous condition?
Homozygous is a genetic condition where an individual inherits the same alleles for a particular gene from both parents.
What are examples of recessive genes?
Examples of Recessive Traits
- Attached earlobes.
- Inability to roll tongue.
- Five fingers.
- Type O Blood.
- Hitch-hiker’s thumb.
- Blue eyes.
- Albinism: an albino lacks pigment or coloration in the skin.
- Sickle cell anemia: abnormal red blood cells make it difficult to transport oxygen throughout the body.
Which is true about homozygous organism?
A ‘homozygous’ organism for a particular trait is described to possess either a pair of dominant alleles (e.g. AA) or a pair of recessive alleles (e.g. aa). True breeding organisms are homozygous since the trait in question can be held constant as they produce the same phenotypic result.