What is an Allele and what is a carrier?

Question

can some one tell me what an allele is and what is a carrier of a inherited desease?

Answer 1

The alleles are the different forms of a gene for a trait. It's kind of like the different flavors of ice cream. They're all ice cream, but different tastes. The alleles are the different forms a certain gene may take. So the gene for height in peas has two possible alleles: tall and short.

A carrier is an individual that has the recessive allele for a trait but does not have the trait itself. The individual is heterozygous.

Answer 2

an allele is something that represents trait. usually traits are expressed with 2 alleles. the trait that showsin the phenotype will be of the dominant allele.

for example, let the allele for brown eyes be B and the allele for blue eyes be b.
Brown is dominant to blue, so, blue is recessive. since alleles are represented by 2 alleles, a person with brown eyes can have BB or Bb genotype. but the phenotype for both is brown. this is because, only the train of the dominant allele is expressed (B)
so, to have blue eyes, one must have only bb. only then, blue eyes would be the phenotype.


A carrier is a person who has an allele of the trait but does not express it. in case of diseases, only diseases with recessive genes can have carriers. this is because, the dominant trait will be expressed.
let's say, A is the normal allele. a is the recessive and diseased allele.
a person with AA is normal
A person with Aa looks normal, but is a CARRIER of the recessive gene.
a person with aa is diseased.

therefore, a carrier of the disease is actually heterozygous by genotype, and normal by phenotype.

i hope this clears ur doubts.

Answer 3

allele= alternative form of a gene.

it is formed by mutations in the original gene.

example:
round shape of pea seed is a gene (R).
its allele is wrinkled pea seed (r)



carrier =
is the one which has a particular gene but expression of it do not takes place due to heterozygous condition.

example:
A= is gene for a disease
but it only expresses only in homozygous condition (AA)

and not in heterozygous condition (Aa)

so a person with genotype (Aa) will be carrier of that disease.
but he do not suffers from that particular disease.

Answer 4

that's genetics