alleles biology definition
An allele is one of a pair of genes that appear at a particular location on a particular chromosome and control the same characteristic, such as blood type or colorblindness. Alleles are also called alleleomorphs. Your blood type is determined by the alleles you inherited from your parents. Of or relating to two alleles of a gene that are both fully expressed in a heterozygote. 2. Being one of two or more of the most common or important species in an ecological community and influencing the presence and type of other species in the community. Because of the presence of 2 codominant alleles (Hp1 and Hp2), 3 major haptoglobin phenotypes are known in man: Hp 1-1, Hp 2-1, and Hp 2-2 (3). Vitamin C deficiency and scurvy are not only a dietary problem but are codetermined by the haptoglobin polymorphism. There are three common codominant alleles, designated [epsilon]2, [epsilon]3, and [epsilon]4 (2). Allele vs. Gene. A gene is a stretch of DNA or RNA that determines a certain trait. Genes mutate and can take two or more alternative forms; an allele is one of these forms of a gene. For example, the gene for eye color has several variations (alleles) such as an allele for blue eye color or an allele for brown eyes. Because of the presence of 2 codominant alleles (Hp1 and Hp2), 3 major haptoglobin phenotypes are known in man: Hp 1-1, Hp 2-1, and Hp 2-2 (3). There are three common codominant alleles, designated [epsilon]2, [epsilon]3, and [epsilon]4 (2). An allele is one of the possible forms of a gene. Most genes have two alleles, a dominant allele and a recessive allele. If an organism is heterozygous for that trait, or possesses one of each allele, then the dominant trait is expressed. A recessive allele is only expressed if an organism is homozygous for that trait, or possesses two recessive alleles. Alleles were first defined by Gregor Mendel in the law of segregation. genetics alleles genes. When studying heredity one of the most common things to mess up is the terms gene and allele. There can be several variations of this sequence, and each of these is called an allele. In the case of the gene for eye color, for example, one allele codes for blue eyes, whereas the other may code for brown eyes. Diffen › Science › Biology › Molecular Biology. A gene is a stretch of DNA or RNA that determines a certain trait. Genes mutate and can take two or more alternative forms; an allele is one of these forms of a gene. If your mother's blood type is A and you know she's homozygous (that is, her alleles are the same, both of them A) and your father's blood type is O (since type O is a recessive trait, he would have to be homozygous, too), then you’ve inherited an A and an O allele — and your blood type is A. Definitions of allele. Any of the possible forms in which a gene for a specific trait can occur. In almost all animal cells, two alleles for each gene are inherited, one from each parent. Paired alleles (one on each of two paired chromosomes) that are the same are called homozygous, and those that are different are called heterozygous. In heterozygous pairings, one allele is usually dominant, and the other recessive. Complex traits such as height and longevity are usually caused by the interactions of numerous pairs of alleles, while simple traits such as eye color may be caused by just one pair.
One of the possible forms of a gene.