Practice question

In linear octad containing four pairs sister spores from postmeiotic mitosis, arrangement with two genotype blocks, such as AAAAaaaa contiguous or AAcc pattern where identical sisters adjacent, shows alleles partitioned at meiosis I reductional division. No crossover between gene and centromere preserved linkage, homologous centromeres with alternative alleles diverged at anaphase I, producing first division segregation pattern 4:4 or 2:2 block. Distal genes exhibiting crossover display alternating 2:2:2:2 patterns indicating second division segregation. Discrimination essential for measuring gene-centromere recombination distances.