Codominance and Incomplete Dominance: Non-Mendelian Genetics

Some traits don't follow the rules of Mendelian Genetics! This tutorial explains the concepts of co-dominance and incomplete dominance; two common exceptions to traditional genetics.

Organisms that inherit traits via complete dominance will show the dominant trait in their phenotype. In this case, it would be a blue phenotype. Only one allele is dominant.

Organisms that inherit traits via co-dominance will display BOTH phenotypes; in this case yellow and blue polka dots. BOTH alleles are dominant. A real life example is cow coat color. A red cow crossed with a white cow will produce a calf that has red and white patches on its coat, a pattern called "roan".

Organisms that inherit traits via incomplete dominance will display a BLEND of phenotypes. In this case, the offspring would be green, a combination of blue and yellow. Neither allele is completely dominant. Real life examples include snapdragon flowers; a red flower crossed with a white flower will produce a pink flower.

00:00-00:21 Introduction
00:22-00:45 Punnet Squares Complete Dominance
00:45-00:56 Non Mendelian Genetics
00:56-1:41 Types of Dominance: Homozygous Dominant
1:41-1:51 Types of Dominance: Homozygous Dominant
1:51-2:38 Types of Dominance: Heterozygous
2:38-3:02 Codominance: Roan Cows & Blood Type
3:02-3:20 Incomplete Dominance: Flower Petals & Hair Texture
3:20-4:09 Definitions of Complete, Codominance and Incomplete Dominance

Avoid plagiarism! Cite BOGObiology!

#codominance #incompletedominance #genetics

[rmula]

This was so so so so helpful! I just found this! Thank you so much for making this video!!!

[jakobbrown]

Why did my lecturer spend so long talking about these !!! He coulda just shown this video, and would have lead to me having a better understanding. Thank you! very clear.

[isabelvelascoaranguena]

Thank you for this video! Clear, informative and even cute!

[aashnishah]

Thank you so much!! I used it to study for my science test tomorrow

[matthewmaddox]

Wow! That was very helpful. My teacher assigned this and it was very helpful

[MrfosteratDV]

From my understanding Incomplete dominance may appear as a blend but is truly not a blend of the two alleles. Incomplete dominance produces an intermediate phenotype between the two homozygous phenotypes. One phenotype is not completely masked and thus less of the dominant phenotype shows up. You are still able to get back to the original dominate and recessive phenotypes by crossing the heterozygous forms.

[HawkRBX]

Very helpful! I’ve seen this come up in distance learning.

[clarissegajes]

Omg!!! Thanks for doing this video it's so so so helpful!!!! Thankyouuu❤️❤️❤️

[henrysupple]

Great video! Sorry you have to put up with all these people leaving horrific comments on your videos. =(

[zizojaezekeom]

Amazing explanation however our professeur explained incomplete dominance in a weird manner, he said that only one allele is expressed and the other isn't however the one expressed isn't fully manifested but your explanation makes more sense but I'm confused 😅 he also said that incomplete dominance is actually two types: co dominance and semi dominance, it's sad that i understand everything however don't know the right terminology i looked up on google and no one is saying what's he's saying

[ivanmarquez]

Great video, very clear and informative. I wish you all the likes and subscribers!!! #biolife

[민쨩-pf]

Thank you so much for good explanation!

[izg]

Damn i understand this more than my teacher's lectures

[tyborg]

What happens if you cross a complete dominant gene with a incomplete dominant/co-dominant gene, little confused about that aspect. Like is co-dominance just when you mix two complete dominant genes together or is co-dominant it's own type of gene that requires another co-dominant gene for both to express. I know incomplete dominant genes can blend with homozygous recessive genes, but can incomplete genes blend with co-dominant genes or complete dominant genes?

[sheraznarejo]

Also u should have to made simple like this on polygenic traits epistasis and pleiotrophy

[letmein]

You can't breed a cow with a cow. You need a bull!!! Ha. Ha. Ha.

[xxmillionairxx]

do not lie to them this is not very helpful