Thread: Can someone explain to me the difference between dominant and recessive genes?

And people use a language that I understand (don't use big words)

dominant allele is an allele that is phenotypically expressed in heterozygous genotype but the allele that is hidden or not expressed in heterozygous genotype is called recessive allele.

Dominant is a bigger chance of happening. Recessive is a smaller chance of happening.

For instance. Let's use the trait blue eyes. B is for Dominant and b is for Recessive.

BB will be blues eyes. Bb will be blue eyes. bb will be brown eyes.

So there's a bigger chance of having blue eyes than brown eyes.

Make sense?

A dominant allele (the version of the trait that the gene determines - for example, in corn, tall and short are the two alleles possible in the gene that codes for tallness) is the one that is expressed (shown by the person who has it) even when both alleles are present. In other words, an individual can be either homozygous (homo means same) and have TT - that corn plant would be tall. However, an individual that was Tt (this is called heterozygous - hetero means different) would also be tall. Only an individual that has both recessive alleles (that is, one on each of the pair of homologous chromosomes) and is tt, would be short.

Sorry if these words are too long - one of the things you have to do to understand biology is to learn the words, before you can really understand the concepts.

Dominant genes are the ones that will prevail (or be expressed) if paired with a recessive gene.
Think of it this way in a table, say looking at brown and blue eyes.

Gene of each Results in
Father Mother Child
Dominant Domintant Dominant
Brown Brown Brown
----------------------------------------------
Dominant Recessive Dominant
Brown Blue Brown
----------------------------------------------
Recessive Dominant Dominant
Blue Brown Brown
----------------------------------------------
Recessive Recessive Recessive
Blue Blue Blue

In this example it is important to note that both the Father and Mother may have Brown eyes, but it is the genes they are passing along we are talking about. A recessive attribute will only be expressed when both Father and Mother pass the recessive gene along to the child.