One allele for every gene in an organism is inherited from each of that organism’s parents. In some cases, both parents provide the same allele of a given gene, and the offspring is referred to as homozygous (“homo” meaning “same”) for that allele.
Where do all new genetic alleles come from?
Genetic variation can be caused by mutation (which can create entirely new alleles in a population), random mating, random fertilization, and recombination between homologous chromosomes during meiosis (which reshuffles alleles within an organism’s offspring).
Why are there two alleles for each gene?
Since diploid organisms have two copies of each chromosome, they have two of each gene. Since genes come in more than one version, an organism can have two of the same alleles of a gene, or two different alleles. This means that if a pea plant has two red alleles, its flowers will be red. …
What pairs of alleles determine?
The pair of alleles present on an individual’s chromosomes dictates what eye color will be expressed.
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.
How are alleles represented in genetics?
Each pair of alleles represents the genotype of a specific gene. For example, in sweet pea plants, the gene for flower color has two alleles. One allele codes for purple flowers and is represented by the uppercase letter F, whereas the second codes for white flowers and is represented by the lowercase letter f.