Recessive Gene?

Question

What does recessive gene exactly mean?

Answer 1

The term "recessive gene" is a gene that is not visible as a  characteristic of the organism unless the organism has two copies of it. (In case you see the word, "Diploid" means that the genes are in this two-copy system.)

In people, you generally have two copies of your genes. Plants do, too. You can do this will TONS of different genes, such as the color of pea pods, etc  but lets use a simple example to understand. Take for example the gene that makes you able or unable to roll your tongue into a U-shaped tube. You get one copy of this gene from your mother and one from your father.

Whatever two versions you have, that is your genotype.

Your parents each have two versions, and you inherit one of the two versions from each of them. So, the possible genotypes are:

Yes-Yes

Yes-No

No-Yes

No-No

If you have even ONE copy of the dominant "Yes" form of a gene, that is the form that shows as part of your phenotype (which means the genes that show up and are expressed.) So in other words, you only need ONE copy of the "Yes" version of the tongue-rolling gene to be able to do it. You might also have the recessive "No" form of the gene, but that doesnt show because it is recessive. It doesnt show because the dominant form is "stronger" and overrides it.

The only way the recessive version of a gene shows as your phenotype (in this case, the only way you cannot roll your tongue into a tube) is if BOTH copies in your genotype are the recessive "No" version.

Yes-Yes: You can roll your tongue.

Yes-No: You can roll your tongue.

No-Yes: You can roll your tongue.

No-No: You cannot roll your tongue.

So, even though there are four different gene combinations possible, 3 of the four combinations appear the same. Only one is different and shows the recessive version.

These same ideas apply to all sorts of other living organisms, including of course plants. I hope that helps!

Answer 2

The hidden Gene from a parent or the one that was not the strongest/ the one you didn't get.

Answer 3

I generally like to think of a recessive allele as having a missing step in the production of something ( and the dominant allele has.

Note:An allele is the version of a gene, either dominant or recessive version of a gene.

For example...blue eyes is recessive and brown is dominant. The brown allele produces pigment in the eye, while the blue eye does not.

Sometimes there are several biochemical processes occurring to produce a trait or characteristic and if a step is missing you will not get the final ( and dominant) trait.

There are many diseases that are recessive including red/green colourblindess, haemophilia ( inability to clot blood), cystic fibrosis etc etc,

If you have the dominant allele then this will code for the correct processes to occur and you will get the final product and see the dominant trait as a result.

Answer 4

A recessive gene is one where the phenotype of the gene is not expressed unless there are two copies of that allele.

For instance, if the allele R (for red flowers) is dominant to r (for white), a plant with two copies of the recessive rr allele will have white flowers.

Plants with the genotypes of RR or Rr will have red flowers.

The allele r is recessive.