Q16 - Pedigree Analysis of Two Rare Traits
The inheritance pattern of two rare traits, represented as vertical and horizontal lines, is shown in the pedigree below. Inheritance of one of the traits is Y-linked.
Figure 1.
Using the information and data, determine which of the statements are true or which are false.
A. Inheritance of one of the traits is Y-linked.
B. The data presented is consistent with autosomal recessive inheritance for both traits.
C. The phenotype of III-2 may be due to non-disjunction in II-2.
D. The phenotype of III-2 may be due to cross over in II-2.
E. The probability of the phenotype of III-2 being due to a mutation that occurred in an egg cell of II-2 before fertilization is twice the probability of the phenotype of III-4 being due to a mutation that occurred in an egg cell of II-2 before fertilization.
Question reproduced from IBO 2018, Theoretical Paper 2, licensed under CC BY-NC-SA 4.0 - attributed to the International Biology Olympiad. Open the full exam PDF · Community solutions (unofficial)