Types of Genetic Inheritance

If two alleal for a gene differ, one could dominate the phenotype.

• In order to see the recessive gene, a plant needs two copies of their traits.
• In order to see the dominant gene, the plant only need one copy of the trait

But….. What's actualyl happening?

The "recessive" gene usually is a gene that does not code for the functional enzyme. Hence, if you have one alleal with the functional DNA, even if the other alleal is broken, a functional enzyme is created and hence the individual will "express" this trait. It is only with both copies being broken that the enzyme that create that trait will not exist and hence can't function.

Both alleals ale visible in the phenotype, and so neither is dominant really. Think about the genetic explanation of inherintance above. In the case of "incomplete dominance", not enough enzymes is created to fully express a trait (like "red pigment") such that the resulting organism will have an "incompletely" dominant trait.

Both alleals are fully present. For instance, in blood types, the AB alleals will result in their codominance to created AB blood. This is different from incomplete dominance in that that is simply a half-mix.

Where a trait exists on the gradient of the combination multiple genes than results in a phenotype.

Alleals that could only be expressed if another alleal is already expressed. For instance, the Ee gene in labrador retrivers control whether a pigment could be deposited. So, if a dog has ee gene, it will have golden coat whether or not the black-ness Bb gene is expressed b/c the lack of colour expression.

• Two X chromasomes: most women
• XY chromasomes: most man

Because men usually only have one X chromasome, even if a sex-linked mutation carries recessively, they do not have a chance of being dominated. Examples of these include red-green colour blindness.