What is the difference between dominant and recessive genes?

Answer 1

I think what you are trying to ask is the difference between dominant and recessive traits (phenotypes or observable characteristics), rather than genes.
In diploid organisms each gene is composed of two alleles, in sexually reproducing organisms one allele is inherited from each parent.
A dominant allele is one that will always cause a trait to be expressed, no matter which other allele is present. A recessive trait will only expressed if there is no dominant allele present.
A simple example:
A plant can be smooth or hairy. The hairy allele is dominant, we'll call it H. The smooth allele is recessive, we'll call it h.
Since an organism has two alleles present, it can either have the genotype (allele combination)
HH
Hh
hh
Plants with the genotype HH or Hh are hairy, plants with the genotype hh are smooth.
Check here for some more information: http://en.wikipedia.org/wiki/Recessive_allele

Answer 2

Well as you know there are several types of genes. Two of them are Dominant and Recessive genes. Let us consider an example, ok?

M is a man with white skin and W is a woman with black skin, suppose they have a child, the child could be either black or white or even and mix of them( which we do not consider here as it a fully different concept).

Suppose the child C is white, then it is because the M's gene acted as the dominant one and the W's gene acted as the recessive. Suppose C is black then it's coz M's gene was recessive and W's was Dominant.

In short during meotic division the gene which dominates in the offspring's chromosome is the DOMINANT one and the gene which succumbs to the dominant is the RECESSIVE.

Answer 3

Genes are that information on the chromosomes that tell your body how it should be... with respect to hair color, eye color, height... blood type.

Now, you'd get a version of each gene from your mom and dad... meaning that you'd have 2 of each gene. Whether a gene is dominant or recessive will dictate whether that gene will be expressed.

Let's take for instance eye color. Blue is recessive, brown is dominant. Let's say now that Mom and Dad both have brown eyes... but then they have a blue eyed baby. No, it's not a mistake. Remember I said that Brown is dominant. so let's look at it this way...Each of the parents has a gene for brown which I'll call B (big b) and one for blue, which is recessive, which i'll call b (small b).... so we have a situation where we have 2 parents... Bb (dad) and Bb (mom)... Now, just like the parents, (dad's info will come first) the baby will have 2 copies of the same gene for eye color... and based on the parents' genetic information, it would be either Bb (brown eyes) BB (brown eyes) or bb which is blue eyes... This baby evidently got the bb genotype (genetic information) meaning he got the recessive (blue) from his dad and another recessive from his mom. (of course in real life, it's not this precise... cos then we'd have only blue and brown eyed people, but instead we have gray and green and all inbetween!)

Let's take something else... sickle cell anemia... This information is recessive... so let's have dad as AA and mom as aa... now all the babies they have will be Aa... Sickle cell anemia is recessive... so they will show that they don't have the anemia, but they will have the trait, so they can pass it down to their children... which is why there is genetic counseling. However let's make dad Aa and mom Aa... Neither one of the parents has sickle cell anemia. but they can both pass it on to their kids... that is if the baby inherits aa. But they can also produce children that are Aa and AA.

So that's pretty much it about the dominant and recessive genes. People have 2 copies of each gene, but a recessive gene will only be expressed (called its phenotype) ONLY if both copies are recessive. A dominant gene will be expressed whether both copies are dominant or not.

Answer 4

Coo you've got some long answers. I'll try and give you a shorter one, with the main points explained.

A dominant gene is one which 'wins' against a recessive gene. For an example let's say that there are two genes possible for eye colour. One gives brown eyes (and is dominant), and the other gives green eyes (and is recessive). Each person has two genes for eye colour in their DNA. If you have two brown eye genes, you obviously get brown eyes. If you have two green eye genes you obviously get green eyes. If you have one brown eye gene and one green eye gene, you will have brown eyes as brown is dominant.

Answer 5

Everyone has a mix of dominant and recessive genes. Genes come in pairs- one from your mother and one from your father. A dominant gene will always be expressed over a recessive gene. The only way recessive genes get expressed if both of your genes from your mother and fater are recessive. For example, say brown eyes are dominant and blue are recessive (dunno if that's true). The only way you end up with blue eyes is if you get that gene from both parents. If you get one brown and one blue, brown wins out because it's dominant.

Answer 6

In genetics, the term "recessive gene" refers to an allele that causes a phenotype (visible or detectable characteristic) that is only seen in a homozygous genotype (an organism that has two copies of the same allele) and never in a heterozygous genotype. Every person has two copies of every gene, one from mother and one from father. If a genetic trait is recessive, a person needs to inherit two copies of the gene for the trait to be expressed. Thus, both parents have to be carriers of a recessive trait in order for a child to express that trait. If both parents are carriers, there is a 25% chance with each child to show the recessive trait.

The term "recessive gene" is part of the laws of Mendelian inheritance created by Gregor Mendel. Examples of recessive genes in Mendel's famous pea plant experiments include those that determine the color and shape of seed pods, and plant height.

In genetics, the term dominant gene refers to the allele that causes a phenotype that is seen in a heterozygous genotype. Every person has two copies of every gene, one from mother and one from father. If a genetic trait is dominant, a person only needs to inherit one copy of the gene for the trait to be expressed.

Dominance/recessiveness refers to phenotype, not genotype. Consider sickle cell anemia as an example. The sickle cell genotype is caused by a single base pair change in the beta-globin gene. There are several phenotypes associated with the sickle genotype: 1) anemia (a recessive trait), 2) blood cell sickling (partially dominant), 3) altered beta-globin electrophoretic mobility (codominant), and 4) resistance to malaria (dominant). This example demonstrates that one can only refer to dominance/recessiveness with respect to individual phenotypes.