Final answer:
Polyploid plants with an odd number of chromosome sets are generally sterile, while those with an even number are typically fertile.
Step-by-step explanation:
Polyploid plants that have an odd number of chromosome sets are usually sterile, and those with an even number of chromosome sets are usually fertile. Polyploidy in plants can lead to individuals that are larger and more robust compared to their euploid counterparts. Odd-number polyploids experience difficulties during meiosis because one set of chromosomes has no pair, which leads to sterility. In contrast, plants with an even number of chromosome sets can undergo normal meiotic processes, leading to fertility.