Genes vs alleles?

Question

i am really confused about the relationship between genes and alleles. can someone help please

Answer 1

A gene is a locatable region of genomic sequence, corresponding to a unit of inheritance, which is associated with regulatory regions, transcribed regions and/or other functional sequence regions.The physical development and phenotype of organisms can be thought of as a product of genes interacting with each other and with the environment. A concise definition of a gene, taking into account complex patterns of regulation and transcription, genic conservation and non-coding RNA genes, has been proposed by Gerstein et al."A gene is a union of genomic sequences encoding a coherent set of potentially overlapping functional products".

Colloquially, the term gene is often used to refer to an inheritable trait which is usually accompanied by a phenotype as in ("tall genes" or "bad genes") -- the proper scientific term for this is allele.

An allele  is one member of a pair or series of different forms of a gene. Usually alleles are coding sequences, but sometimes the term is used to refer to a non-coding sequence. An individual's genotype for that gene is the set of alleles it happens to possess. In a diploid organism, one that has two copies of each chromosome, two alleles make up the individual's genotype. Alleles are prominently represented in a Punnett square.

An example is the gene for blossom colour in many species of flower — a single gene controls the colour of the petals, but there may be several different versions (or alleles) of the gene. One version might result in red petals, while another might result in white petals. The resulting colour of an individual flower will depend on which two alleles it possesses for the gene and how the two interact.

Answer 2

An allele is one member of a pair or series of different forms of a gene. A gene is a locatable region of genomic sequence, corresponding to a unit of inheritance, which is associated with regulatory regions, transcribed regions and/or other functional sequence regions.

For more, read:

http://en.wikipedia.org/wiki/Allele

http://en.wikipedia.org/wiki/Gene

Also see:

http://www.accessexcellence.org/AE/AEPC/...

Answer 3

yes genes work in pairs of alleles.  Lets say the gene of eye color is the gene we'll call  "C" and an allele is a particular variation or version of that gene so that the allele for blue eyes we could call Cb for the blue eye allele, CB for brown eye allele, etc.

but because it works as pair we need to say what each alleles is to describe a "genotype": such as

Cb/Cb (blue eyes), Cb/CB (brown eyes)  or CB/CB (brown eyes)

you should note that the even though both Cb/CB and CB/CB both result in brown eyes (because the Brown eye allele is dominant and indicated with a capital B) they are not the same genotype.  They *are the same phenotype which is saying on the outside they both look the same.

hope it helps a little