do now p. 65 in summer squash, white fruit color (w) is dominant over yellow fruit color (w). and...
TRANSCRIPT
Do Now• P. 65
• In summer squash, white fruit color (W) is dominant over yellow fruit color (w). And disk-shaped fruit (D) is dominant over sphere shaped fruit (d). If a squash plant true-breeding for white disk-shaped fruit is crossed with plant true-breeding sphere yellow fruit. What will be the phenotypic and genotypic ratio?
Case Study• How would you determine whether or not the
parents and the sibling are related to Jennifer? Are they related?
• Take 7 min to come up with an idea as to how you would solve.
TODAY WE WILL…Discuss what incomplete and codominance are
Understand how In/Codominance patterns occur—simple calculations
Predict whether the inheritance pattern of an individual is inherited through incomplete or codominance.
Read pages 91-93
Start at “Different Dominance Relationships” and STOP at “Epistasis”1. What is codominance?2. What is incomplete dominance?3. Give an example of each.
Quick Cap• Mendel looked at peas and their traits, and so
far we have discussed single-gene inheritance and looked at dihybrid crosses/punnett squares.
• Although this was seen in pea plants, inheritance can follow more complex patterns that are not as obvious as dominance and recessiveness
Quick Cap• Recessiveness usually entails that there is a
deficiency in the amount of protein made. When an individual is heterozygous, the dominant allele compensates for the lack of protein made by the recessive allele.
Codominance• This pattern of inheritance usually requires
that different alleles that are both dominant are expressed.
Codominance—blood type• Blood types are a great example of codominance• Blood type is dictated by the presence or lack of antigens on
the surface of red blood cells (RBC’s)• IA can represent A Blood type• IB can represent B type• i represents O type: aka no presence of antigens
Incomplete Dominance• This requires that the heterozygous phenotype is
intermediate between that of any homozygote. • A 3rd phenotype is created. Resembles blending
Engage: Whiteboard Practice
Incomplete or codominance?Black hen and white hen mate to make a black and white spotted hen.
Engage: Whiteboard Practice
Incomplete or codominance?Black hen and white hen mate to make a grey rooster.
Engage: Whiteboard Practice
Incomplete or codominance?When a red flower and white flower are crossed to make a pink flower.