Alleles contribute to the organism’s phenotype, which is the outward appearance of the organism. Some alleles are dominant or recessive. When an organism is heterozygous at a specific locus and carries one dominant and one recessive allele, the organism will express the dominant phenotype.
What do alleles affect?
Genes do control different traits of an organism, such as hair color or eye color, but the actual expression of a trait depends on which allele is dominant. For example, the gene for eye color in humans can have an allele for brown eyes and an allele for blue eyes, or an allele for brown eyes and one for green eyes.
What is the purpose of an allele?
2 Alleles are located on chromosomes, which are the structures that hold our genes. Specifically, alleles influence the way our body’s cells work, determining traits and characteristics like skin pigmentation, hair and eye color, height, blood type, and much more.
What are alleles and how do they affect our traits?
Each variation of a gene is called an allele (pronounced ‘AL-eel’). These two copies of the gene contained in your chromosomes influence the way your cells work. The two alleles in a gene pair are inherited, one from each parent. Alleles interact with each other in different ways.
Where do we get our alleles from?
“Allele” is the word that we use to describe the alternative form or versions of a gene. People inherit one allele for each autosomal gene from each parent, and we tend to lump the alleles into categories.
What is the best definition of allele?
Allele, also called allelomorph, any one of two or more genes that may occur alternatively at a given site (locus) on a chromosome. Alleles may occur in pairs, or there may be multiple alleles affecting the expression (phenotype) of a particular trait.
Why do alleles occur in pairs?
Because chromosomes come in pairs for each trait, there will be two possible alleles. These different versions of genes (alleles) occur as the DNA base sequence is different. This combination of alleles for each trait is called the genotype; this can be any combination of two of the available alleles.
How many allele combinations are there?
The total possible combination of alleles for those genes in humans is approximately 70,368,744,177,664. This is trillions of times more combinations than the number of people who have ever lived. This accounts for the fact that nearly everyone, except monozygotic twins, is genetically unique.