Dominance: Co-Dominance, Incomplete Dominance and Blood Types

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Dominance: Co-Dominance, Incomplete Dominance and Blood Types. Lesson Objectives. Minds ON Yesterday’s Recap Dominances and Blood Types Blood Typing Lab Success Criteria Homework Take Up New homework . Minds ON. - PowerPoint PPT Presentation

Transcript of Dominance: Co-Dominance, Incomplete Dominance and Blood Types

Types of Dominance and Blood Types

Dominance: Co-Dominance, Incomplete Dominance and Blood Types

Lesson ObjectivesMinds ONYesterdays Recap Dominances and Blood TypesBlood Typing LabSuccess CriteriaHomework Take Up New homework

Minds ONTwo rabbits are heterozygous. Brown fur (B) is dominant to white fur (b). Dwarf (small) ears (D) are dominant to floppy ears (d). Draw a Punnett square showing the possibilities.

Well do it together on the board once youve tried it. Yesterdays RecapDihybrid CrossesRefers to the crossing of two individuals who are both heterozygous for TWO traits (e.g. PpTt x PpTt)Assumes that these traits are on different genes and can occur at the same time.

E.g. Pod colourand seed colour

Dihybrid CrossesParent 1 genotype is: AaBb

Parent 2 genotype is: AaBb

DominancesSo far, we have been looking at situations where a dominant trait completely masks the allele

Bb/BB = dominant for purple colour

Incomplete DominanceOccurs when:Neither gene is dominant or recessiveThe gene effect is mixed We use 2 different letters for the homologous pair since neither is dominant.

An Example of Incomplete DominanceWith red and white snapdragons, the dominant allele that codes for the colour red is not completely dominant over the recessive allele that produces the white colour. The result is a pink flower. Using a Punnett SquareRed Flower RR White Flower WW

R= 100% Pink Offspring xWWRRWRWRRWRW

9Co-DominanceOccurs when:Neither gene is dominant or recessiveGene effects are NOT mixedTherefore, both genes are expressed at the same time!Examples: Roan cow or Camelia flower

An Example of Co-Dominance Write C (for co-dominance) and a super script (R=Red, W=white)Red haired = CRCRWhite haired = CWCWRed and White (Roan) =CRCW

Using a Punnett Square Red haired = CRCRWhite haired = CWCWRed and White (Roan) =CRCW= 100% Roan

Blood Types A Special Case There are three alleles: IA (Type A), IB (Type B) and i (Type O)A and B are co-dominantO is recessive+/- is the Rh (Rhesus) factor (if the Rh blood antigen is present, the person is Rh+; if not, they are Rh-)

Predict offspring bloodtypes for: Heterozygous type A mother, type O father

Using A Punnett SquareIA (Type A), IB (Type B) and i (Type O)-A and B are co-dominant-O is recessive50% = A5-% = OBlood Types TypesDistributionRatiosO+1 person in 338.4%O-1 person in 157.7%A+1 person in 332.3%A-1 person in 166.5%B+1 person in 129.4%B-1 person in 671.7%AB+1 person in 293.2%AB-1 person in 1670.7%AB universal plasma donors

AB+ universal recipients

O+ blood most needed

O- universal RBC donorRhesus DiseaseAn individual either has, or does not have, the "Rhesus factor" on the surface of their red blood cells. The status is usually indicated by Rh positive (Rh+ does have the D antigen) or Rh negative (Rh does not have the D antigen) suffix to the ABO blood type.Rhesus Disease occurs when there is incompatibility between blood types of mother and fetus.Untreated, the result can cause death of the child.Occurs in second and later pregnancies

Murder Mystery LabI THINK THERES BEEN(sunglasses on)..AN ACCIDENT! (with emphasis)

The Jim Carrey shows us

LabTheres been a murder. Hortatio needs your help! You have to find out who did it. Agglutination: refers to the clumping effect of blood when it is mixed with Anti-A , Anti-B or Rh serum . Go around to each station and sample the blood to find out the blood type and Rh factor to determine who killed One-Eyed Earl!