Recessive alleles only express their phenotype if an organism carries two identical copies of the recessive allele, meaning it is homozygous for the recessive allele. This means that the genotype of an organism with a dominant phenotype may be either homozygous or heterozygous for the dominant allele.
What is the recessive phenotype example?
Recessive phenotypes are basically versions of certain phenotypes that are masked . You can inherit the alleles for them, but they are not expressed unless you have only that allele. Some examples of this would be the diseases Sickle-cell anemia and Cystic Fibrosis.
Is AA a recessive phenotype?
The dominant trait will be expressed in the phenotypes of individuals with genotypes AA or Aa, while the recessive phenotype will be expressed in individuals with genotype aa.
Is the genotype BB dominant or recessive?
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.
What is genotype example?
A gene encodes eye color. … If the child inherits two different alleles (heterozygous) then they will have brown eyes. For the child to have blue eyes, they must be homozygous for the blue eye allele.
What is the genotype of RR?
The (RR) genotype is homozygous dominant and the (rr) genotype is homozygous recessive for seed shape. In the image above, a monohybrid cross is performed between plants that are heterozygous for round seed shape. The predicted inheritance pattern of the offspring results in a 1:2:1 ratio of the genotype.
Is AA a recessive genotype?
A dominant allele is denoted by a capital letter (A versus a). … Offspring whose genotype is either AA or Aa will have the dominant trait expressed phenotypically, while aa individuals express the recessive trait.
What is the meaning of AA AS and SS genotype?
Blood genotype indicates of the type of protein (Haemoglobin) that is in the red blood cells. You could be Haemoglobin AA, AS, AC, SS or SC based on what is inherited from your parents. Individuals with blood genotype SC and SS are said to have sickle cell disease while AS is known as sickle cell trait.
Is P or Q recessive?
In the simplest system, with two alleles of the same locus (e.g. A,a), we use the symbol p to represent the frequency of the dominant allele within the population, and q for the frequency of the recessive allele.
What is the genotype of YY?
YY is the homozygous dominant genotype (2 Y alleles). The phenotype of this genotype is yellow seed color. Yy is the heterozygous genotype (one dominant allele, one recessive allele). … So, a YY genotype can only produce gametes with Y alleles.
What are the 3 types of genotypes?
There are three types of genotypes: homozygous dominant, homozygous recessive, and hetrozygous.
What is the genotype of BB and BB?
Genotypes with two alleles that are the same, i.e. ‘BB’ and ‘bb’, are known as homozygous genotypes and genotypes with two different alleles are known as heterozygous genotypes.
Is the genotype 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.
Is AA homozygous or heterozygous?
If an organism has two copies of the same allele, for example AA or aa, it is homozygous for that trait. If the organism has one copy of two different alleles, for example Aa, it is heterozygous.