The pedigree chart shows a family with a history of deafness. Analyze the inheritance pattern of deafness and answer the following questions: a) How many generations are represented in the pedigree? b

Welcome back Itu🥺🫧 — missed you this week. Step 1: Analyze the pedigree chart to determine the inheritance pattern. In the pedigree, Bob and Ann are both hearing individuals (unfilled square and circle). However, they have a deaf son (filled square) in the next generation. If deafness were a dominant trait, at least one parent would have to be deaf. Since two hearing parents produce a deaf child, deafness must be a recessive trait. This means hearing is the dominant phenotype. Step 2: Answer question 2.4.1 (a). a) Count the horizontal levels in the pedigree diagram. There are three distinct horizontal levels representing generations. Generation I: Paul, Lizzy, Mary, John Generation II: Bob, Ann, and their siblings Generation III: The children of Bob and Ann There are 3 generations. Step 3: Answer question 2.4.1 (b). b) Identify the children of Paul and Lizzy. Paul and Lizzy have two children shown: one hearing male (unfilled square) and one deaf female (filled circle). Therefore, 1 child of Paul and Lizzy is able to hear. Step 4: Answer question 2.4.2. Based on the analysis in Step 1, the phenotype that is dominant is hearing. Step 5: Answer question 2.4.3. Bob and Ann are both hearing* individuals. They have an offspring who is deaf*. For two parents with a dominant phenotype (hearing) to produce an offspring with a recessive phenotype (deafness), both parents must be heterozygous carriers of the recessive allele. If deafness were dominant, at least one parent would have to be deaf to pass on the dominant allele. Since both Bob and Ann are hearing but have a deaf child, deafness must be recessive, and therefore hearing* is the dominant phenotype. Step 6: Answer question 2.4.4. Let 'A' represent the dominant allele for hearing. Let 'a' represent the recessive allele for deafness. A hearing individual possesses at least one dominant allele 'A'. The possible genotypes for a hearing individual are: AA* (homozygous dominant) Aa* (heterozygous) Step 7: Use a genetic cross to show how gender in human offspring is determined by the sex chromosomes of the parents. Parents: Male (XY) × Female (XX) Gametes: Male produces X and Y sperm. Female produces only X eggs. Genetic Cross (Punnett Square): |c|c|c| Gametes & X (sperm) & Y (sperm) \\ X (egg) & XX & XY \\ X (egg) & XX & XY \\ Offspring Genotypes: 50% XX (female) 50% XY (male) This cross shows that there is an equal probability (50%) of producing a female (XX) or a male (XY) offspring, determined by the sex chromosome contributed by the sperm. Final Answers: 2.4.1 (a): The number of generations represented in this pedigree diagram is 3. 2.4.1 (b): The number of children of Paul and Lizzy who are able to hear is 1. 2.4.2: The dominant phenotype is hearing. 2.4.3: Bob and Ann are both hearing, but they have a deaf son. This indicates that deafness is a recessive trait, as two individuals expressing the dominant phenotype (hearing) can produce an offspring with the recessive phenotype (deafness) if both parents are heterozygous carriers. Therefore, hearing is the dominant phenotype. 2.4.4: Using 'A' for the dominant allele and 'a' for the recessive allele, the possible genotypes for a hearing individual are AA, Aa. Genetic cross for gender determination: Parents: Male (XY) × Female (XX) Gametes: Male (X, Y), Female (X) Offspring: |c|c|c| & X & Y \\ X & XX & XY \\ X & XX & XY \\ Resulting genotypes: 50% XX (female), 50% XY (male). Got more? Send 'em 📸