An animal heterozygous for a reciprocal balanced translocation has the following chromosomes:
           MN • OPQRST
           MN • OPQRjkl
           cdef • ghijkl
           cdef • ghiST

Identify the gametes produced by adjacent-2 segregation. Which if any of these gametes are viable?

Key Concepts

Reciprocal Balanced Translocation

A reciprocal balanced translocation occurs when two non-homologous chromosomes exchange segments without any loss of genetic material. This results in a rearrangement of genes but maintains the overall genetic balance. In heterozygous individuals, such as the one described, this can lead to unique patterns of gamete formation during meiosis, influencing genetic diversity and viability.

Adjacent-2 Segregation

Adjacent-2 segregation is a type of chromosomal segregation that occurs during meiosis in individuals with reciprocal translocations. In this process, homologous chromosomes segregate in such a way that two chromosomes from one pair and two from the other pair are pulled into the same gamete. This often results in gametes with an unbalanced set of chromosomes, which can lead to non-viable offspring due to genetic imbalances.

Viability of Gametes

The viability of gametes refers to their ability to develop into a functional organism upon fertilization. In the context of adjacent-2 segregation, gametes produced may carry duplications or deletions of genetic material, often rendering them non-viable. Understanding which gametes are viable requires analyzing the genetic content and ensuring that they possess the necessary chromosomal balance for successful development.