Let me know if you have any questions about the steps — happy to go over them in class tomorrow.
The ABO blood type is determined by a single gene with three alleles: IAcap I to the cap A-th power IBcap I to the cap B-th power : Alleles IAcap I to the cap A-th power IBcap I to the cap B-th power
| Blood Type | Possible Genotypes | Explanation | | :--- | :--- | :--- | | | I^A I^A or I^A i | At least one dominant I^A allele is present. | | B | I^B I^B or I^B i | At least one dominant I^B allele is present. | | AB | I^A I^B | Both codominant alleles are present. This is a clear genotype. | | O | i i | Two recessive i alleles are present, and no A or B antigens are produced. |
If your lab features a wet-lab component using synthetic blood, remind students that agglutination (clumping) equals presence . Clumping in Well A means the A antigen is present. Clumping in both Well A and Well B means Type AB. No clumping in either means Type O. lab activity blood type pedigree mystery answer key upd
Lab Activity: Blood Type Pedigree Mystery – Answer Key & Teacher Guide (Updated)
Individual — Phenotype — Genotype(s) — Notes
| Blood Type (Phenotype) | Possible Genotype(s) | | :--- | :--- | | | IAIA or IAi | | B | IBIB or IBi | | AB | IAIB | | O | ii | Let me know if you have any questions
The presence of a Type O child is the biggest clue, as it implies both parents must carry the
If you get stuck, always start at the bottom of the pedigree: Find the or Rh- individuals first. Give one of their recessive alleles to each parent. This usually reveals the "hidden" alleles ( −negative ) of the parents.
They have the specific recessive trait (attached earlobes) seen by the witness. | | AB | I^A I^B | Both codominant alleles are present
The key to the mystery is identifying the genotypes of family members based on their blood types (phenotype). Means both parents must carry a lowercase Type AB ( IAIBcap I to the cap A-th power cap I to the cap B-th power ): Means the child must have received IAcap I to the cap A-th power from one parent and IBcap I to the cap B-th power from the other. Individual Joseph IBicap I to the cap B-th power i IBIBcap I to the cap B-th power cap I to the cap B-th power IBcap I to the cap B-th power Rita IAicap I to the cap A-th power i IAIAcap I to the cap A-th power cap I to the cap A-th power IAcap I to the cap A-th power Danny IAicap I to the cap A-th power i Often the key suspect due to heterozygous genotype. Other Offspring Must match parent/grandparent alleles. 3. The Thief Identification (Most Common Solution)
extending downward from a mating line lead to the offspring. Roman Numerals (I, II, III) indicate generations.
IAIBrrcap I to the cap A-th power cap I to the cap B-th power r r iirri i r r (Suggests A- IAirrcap I to the cap A-th power i r r Grandchild A- IAirrcap I to the cap A-th power i r r 🔑 Key Answers & Explanations 1. The Inheritance Patterns