Explanation:

To determine the type of linkage between two genes, we need to analyze the frequency of recombinants.

- If the frequency of recombinants is low, then the genes are closely linked.
- If the frequency of recombinants is high, then the genes are loosely linked or unlinked.

In this case, the two genes are 50 map units apart. This implies that:

- If the frequency of recombinants is less than 50%, then the linkage is complete.
- If the frequency of recombinants is more than 50%, then the linkage is incomplete.

Determination of Linkage Type:

To determine the type of linkage between the two genes, we need to calculate the frequency of recombinants.

- If the frequency of recombinants is less than 50%, then the linkage is either cis or trans.
- If the frequency of recombinants is more than 50%, then the linkage is incomplete.

Cis vs. Trans Linkage:

Cis linkage occurs when two linked genes are located on the same chromosome and on the same side of the centromere. In cis linkage, the two genes are inherited together most of the time.

Trans linkage occurs when two linked genes are located on the same chromosome but on opposite sides of the centromere. In trans linkage, the two genes are inherited independently most of the time.

Conclusion:

- If the frequency of recombinants is less than 50%, then the linkage is either cis or trans.
- If the frequency of recombinants is more than 50%, then the linkage is incomplete.

Therefore, we cannot determine the type of linkage between the two genes based on the information given. We need to perform further experiments to determine the frequency of recombinants.

Two dominant nonallelic genes are 50 map units apart. The linkage is absent/incomplete because Chromosome mapping is based on the fact that genes are linearly arranged in the chromosome and frequency of crossing over is directly proportional to the distance between two genes. Dominant genes show cis arrangement. At 50 map units cis is changed to trans and vice-versa hence no fixed linkage is present.