Incomplete and codominance
Skill 3: Differentiate between the phenotypes of heterozygous offspring when incomplete dominance is displayed versus codominance.
Co-dominance
Co-dominance
I’m co-dominant and so are you
I’m co-dominant and so are you
Repeat
Repeat
I say, ‘red’ and you say, ‘blue’
I say, ‘red’ and you say, ‘blue’
Repeat
Repeat
Red…blue
Red…blue
Repeat
Repeat
Red…blue
Red…blue
Repeat
Repeat
I’m co-dominant and so are you
I’m co-dominant and so are you
Incomplete dominance
Incomplete dominance
Incomplete dominance makes you think
Incomplete dominance makes you think
Repeat
Repeat
Red and white always makes pink
Red and white always makes pink
Repeat
Repeat
Red ‘n white
Red ‘n white
Repeat
Repeat
Makes pink
Makes pink
Repeat
Repeat
Incomplete dominance makes you think
Incomplete dominance makes you think
How many letters are used in the key?
How many letters are used in the key?
When writing a key, consider how many dominant alleles there are. An allele is considered dominant if it shows up in the offspring. In both examples above, both alleles show up in the offspring. They could stay separate as with co-dominance or they could blend together as with incomplete dominance. In both cases, there are two dominant alleles so there will be two letters in the key. For the fish example, you will use 'R' for red and 'B' for blue. The offspring is 'RB' for red and blue. In the flower example, you use 'R' for red, 'W' for white, and 'RW' for pink.
When writing a key, consider how many dominant alleles there are. An allele is considered dominant if it shows up in the offspring. In both examples above, both alleles show up in the offspring. They could stay separate as with co-dominance or they could blend together as with incomplete dominance. In both cases, there are two dominant alleles so there will be two letters in the key. For the fish example, you will use 'R' for red and 'B' for blue. The offspring is 'RB' for red and blue. In the flower example, you use 'R' for red, 'W' for white, and 'RW' for pink.
Complete the page below in your packet, then ask for the answer key to check your work.
Complete the page below in your packet, then ask for the answer key to check your work.
Ask me for the answer key to be sure your work is correct.
Ask me for the answer key to be sure your work is correct.