Recessive alleles are expressed if there is no dominant allele (of the same gene) present.
This can be for two reasons, because the other allele is also recessive, or because there is no other allele (such as X-linked genes, which males only have one copy of).
For a single recessive allele to be expressed in a male, it must be on the X chromosome.
Another way to express something is heterozygous is to say it has dual alleles. There is a dominant and recessive allele. Alleles determine which traits something will have. Normally this is expressed in a single allele.
Alleles affect traits like eye color. Alleles for brown and blue eyes are dominant and recessive respectively. Individuals who have homozygous and heterozygous genotypes with the dominant allele will have brown eyes. However individuals are homozygous for the recessive allele will have blue eyes.
The different forms of a genes for a single trait are known as alleles there can be a dominate allele which always shows up when present and a recessive allele which only shows up when both alleles are recessive or there is no dominate allele
It depends on the gene in question, and the type of dominance of the trait.For monogenetic traits (those controlled by a single gene), the dominant trait(s) will be expressed when two different alleles are present.For example, if B leads to black fur and b leads to white fur:Complete dominance would result in a rabbit with Bb having black fur.Incomplete dominance - Bb would result in grey furCodominance - Bb would result in black and white patches/spots/etc.
Each person has two alleles for their blood type, one dominant and one recessive. Except for type AB blood where the alleles are co-dominant. The allele for O blood is always recessive when paired with either an A or B allele.
Another way to express something is heterozygous is to say it has dual alleles. There is a dominant and recessive allele. Alleles determine which traits something will have. Normally this is expressed in a single allele.
I take it you're referring to the phenotype. Say a trait, like flower colour, is influenced by a single gene. The plant will possess two copies of the gene, one from each parent, but only one colour is expressed. Let's say that red is dominant and white is recessive. A plant containing 2 red alleles (homozygous for the dominant allele) will be red. A plant containing 2 copies of the white allele (Homozygous recessive) will be white and heterozygous plant, containing a single copy of both alleles will be red. There is no heterozygous recessive because the dominant allele will determine the phenotype.
Autosomal recessive alleles ( both males and females) and X-linked alleles in females always express themselves in homozygous condition. On other hand, X -chromosome linked recessive allele express singly in males.
A 3:1 phenotypic ratio (Mendelian inheritance).
If an allele is masked, it is most likely recessive, but not necessarily. This is due to epistasis, the interaction between two or more genes to control a single phenotype. For example, "K" codes for more keratin pigment in the skin, but "k" does not. One can still be albino, however, for if they get the dominant "A" allele, this allelle will override and mask the dominant "K" pigment in the skin, making the person albino.
A sex linked dominant trait could be on the X chromosome of either parent and the phenotype of any individual carrier would be that of the dominant trait. A father with the dominant characteristic on his single X chromosome would produce daughters that are 100% carriers and would not pass the characteristic on to his sons. A mother who is a dominant X linked carrier would pass the dominant characteristic on to half hersons and half her daughters all of which would show the trait phenotypically. A sex linked recessive father would produce 100% carrier daughters. His sons would not get the recessive allele from him. A sex linked recessive carrier (heterozygous) mother would pass the trait on to 50% of her children and 50% of her sons would show the recessive trait genetics.
Alleles affect traits like eye color. Alleles for brown and blue eyes are dominant and recessive respectively. Individuals who have homozygous and heterozygous genotypes with the dominant allele will have brown eyes. However individuals are homozygous for the recessive allele will have blue eyes.
The different forms of a genes for a single trait are known as alleles there can be a dominate allele which always shows up when present and a recessive allele which only shows up when both alleles are recessive or there is no dominate allele
It depends on the gene in question, and the type of dominance of the trait.For monogenetic traits (those controlled by a single gene), the dominant trait(s) will be expressed when two different alleles are present.For example, if B leads to black fur and b leads to white fur:Complete dominance would result in a rabbit with Bb having black fur.Incomplete dominance - Bb would result in grey furCodominance - Bb would result in black and white patches/spots/etc.
Each person has two alleles for their blood type, one dominant and one recessive. Except for type AB blood where the alleles are co-dominant. The allele for O blood is always recessive when paired with either an A or B allele.
okay well the dominant form of an allele, is YO MOM she is the answer to all your problems and yea te va pegar con la mexican chancla
Shared dominance, or co-dominance is when a single gene has more than one dominant allele. In shared dominance both alleles are expressed completely.