What is the meaning of the word allele?
An allele is one of the alternative forms of the same gene.
Allele is word used by Mendel for counter parts of an elementon later called factor and renamed as gene e.g. T and t are alleles for a gene that controls height in pea plant .Nasty allele is not biological term . Note word elementon is technical term used by Mendel , it is not element used in Chemistry .
The term allele is often used interchangeably with the word gene. Allele/gene is used for the variations seen at each gene locus for a trait on the homologous chromosome pair. For example: If there are three alleles for a trait only two of the alleles will be represented in the genotype of any one individual. The alleles for basic blood types A, B and O are examples. In general the term allele is not used…
They are related to each other because whether they are dominant or recessive they are both homozygous, meaning the same. They can either be homozygous dominant or homozygous recessive. If they are heterozygous then they are different because it contains one dominant and one recessive allele each. EX: AA=homozygous dominant allele aa=homozygous recessive allele Aa=heterozygous allele
A blood type O child would be impossible from this match. An AB parent must give an A allele or a B allele, and both alleles are dominant. If mother is homozygous B (meaning both alleles are B's), and father is AB, child can be either B or AB. If mother is heteroygous B (meaning one B allele and one O allele), and father is AB, the child can be either A, B, or AB.
The difference between a dominant allele and a recessive allele is that if a person inherits one dominant allele and one recessive allele the dominant allele will appear as it is stronger or more dominant than a recessive allele the dominant allele is stronger the recessive allele weaker. For instance brown eyes is a dominant allele, blue eyes is a recessive allele. A recessive allele does not always determine the trait.
A dominant allele is an allele where its phenotype will always be represented when the allele for that gene is present. A recessive allele can be masked by a dominant allele when a dominant and recessive allele are present for the same gene. A recessive allele will only present itself when two recessive alleles for a trait are present.
Why can a person be a carrier of a trait cause by a resesive allele but not of a trait caused by a dominant allele?
When one allele of a gene masks the presence of the other allele what form can be seen in the phenotype?
If an allele is dominant, whenever it's in the presence of another allele, dominant or recessive, the trait that the dominant allele carries is present in the organism. If an allele is recessive, the trait that the recessive allele carries is only present in an organism when there is another recessive allele.