22. In Burkitt’sLymphoma a reciprocal translocation between chromosome 8 and 14 is observed. If an individual is heterozygous for this translocation, the consequence in meiosis Will be as follows:
A. Fourchromosomes, i.e., normal chromosome 8 and 14, and translocated chromosome 8 and 14. Pair together
B. The two normal chromosomes 8 and 14, and-two translocated chromosomes pair separately
C. All gametes produced from this meiosis are non- viable as they have deletions and duplications
D. In one of the cross configurations called “alternate all gametes having normal or segregation” translocated chromosomes, survive
E. The gametes having normal chromosomes only survive while all gametes having translocated chromosomes hence the non-viable, are translocations are used as crossover suppressors
Which of the following combinations best describes the meiotic consequences for the translocation described above?
(1) B and E         (2) B, C and E
(3) A, C and E     (4) A and D

Option-wise explanation:

• A. Four chromosomes, i.e., normal 8 and 14, and translocated 8 and 14 pair together – Correct.
  In a reciprocal translocation heterozygote there are two normal and two translocated chromosomes. Homologous segments attempt to align, forming a cross-shaped quadrivalent; all four participate in pairing.

• B. The two normal 8 and 14 and two translocated chromosomes pair separately – Incorrect.
  They do not form two independent bivalents; instead, all four chromosomes form one quadrivalent.

• C. All gametes produced are non-viable – Incorrect.
  Some segregation patterns (adjacent segregations) give unbalanced gametes with duplications/deletions and are often non-viable, but others (alternate segregation) produce balanced gametes.

• D. In one cross configuration, “alternate segregation,” all gametes having normal or translocated chromosomes survive – Correct.
  In alternate segregation, one pole receives both normal chromosomes, the otherpole both translocated chromosomes; each gamete has a complete, balanced set, so these gametes are viable.

• E. Only gametes with normal chromosomes survive; gametes with translocated chromosomes are non-viable and translocations are used as crossover suppressors – Incorrect.
  Balanced translocation gametes (carrying the translocated pair) are usually viable; carriers are phenotypically normal. Also, translocations are not classically described as crossover suppressors in the same way as inversions.

Thus, the statements that best describe the meiotic consequences of the t(8;14) reciprocal translocation are A and D → option (4).