Table of Contents
- 1 What causes differences in genes leading to different alleles?
- 2 Where the two alleles for a certain character are located?
- 3 What is the allele that determines the phenotype with respect to a particular gene?
- 4 Can more than two allele exist for one gene?
- 5 Can two alleles be dominant at the same time?
- 6 Are all alleles at a specific gene locus are identical?
What causes differences in genes leading to different alleles?
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).
Where the two alleles for a certain character are located?
Each allele occupies a specific region on the chromosome called a gene locus. The gene’s two alleles are located in the same region in two homologous chromosomes, one inherited from each parent. The alleles may be dominant or recessive.
What is the allele that determines the phenotype with respect to a particular gene?
The law of segregation states that each individual that is a diploid has a pair of alleles (copy) for a particular trait. Each parent passes an allele at random to their offspring resulting in a diploid organism. The allele that contains the dominant trait determines the phenotype of the offspring.
When two alleles of a pair differ the one that determines the appearance?
When an organism has two different alleles of a gene, one (the dominant allele) will hide the presence of the other (the recessive allele) and determine appearance.
Do all genes have two or more alleles?
Each organism has two alleles for every gene, one on each chromosome. If the two alleles are the same (e.g., both coding for blue eyes), they are called homozygotes. If they are different (e.g., one for blue eyes and one for brown eyes), they are heterozygotes.
Can more than two allele exist for one gene?
In Mendel’s studies, he proposed that there are two alleles for every gene, the dominant of the two having its phenotype expressed in a heterozygote. However, a gene can have more than two allelic forms segregating within a population. These genes are referred to as having multiple alleles. This does not mean that the gene in a particular individual possesses more than two alleles.
Can two alleles be dominant at the same time?
Moreover, some of the genes are codominant: two different dominant alleles can coexist and be visible in the phenotype at the same time. Blood types inheritance is an excellent example of that, since dominant alleles A and B cooperate in creating the AB blood type.
Are all alleles at a specific gene locus are identical?
They can be identical or different for any given gene in a somatic cell. These alleles can br the same or they can be different. Homozygous describes two of the same alleles at a specific locus or location. Both alleles could be the code for blues eyes. Heterozygous describes two different alleles at a specific locus or location.