Answer
Since the results vary with the nature of the male and female parents, but there are no sex chromosomes in these organisms. This must be due to cytoplasmic inheritance, which typically only proceeds from the mother and appears to do so here as well.
Work Step by Step
The key here is to see that there is something like sex-linkage, but that there are no sex chromosomes to allow this. The most logical thing is to look at cytoplasmic inheritance, which resembles sex-linkage in some ways but does not require a sex chromosome system.
