Final answer:
Polyploidy in animals is rare because it disrupts normal meiosis, leading to sterility. Odd numbers of chromosome sets in polyploids prevent proper chromosomal pairing and result in animals that generally cannot produce viable offspring, unlike the frequent occurrence and benefits of polyploidy in plants. Option 3 is the correct answer.
Step-by-step explanation:
Polyploidy in animals is rare because it often results in sterile organisms. This is due to the fact that if polyploidy results in an odd number of chromosome sets, normal meiosis is hindered. One set of chromosomes does not have a pair, making regular meiotic division and the production of viable gametes impossible. Even-numbered polyploidy, while common in plants and associated with greater size and robustness, occurs infrequently in animals, with a few exceptions like some amphibians and fish. Animals with polyploid cells usually do not survive to produce offspring as their meiotic process cannot proceed normally, leading to mostly aneuploid daughter cells.
Polyploidy in animals is rare due to the potential for sterility. Odd-numbered polyploidy disrupts meiosis, impeding regular division. With an uneven chromosome set, lacking a pair for proper meiotic processes, the production of viable gametes becomes impossible. In contrast to plants where even-numbered polyploidy is common and correlates with enhanced size, animals exhibit infrequent instances. Some exceptions, like certain amphibians and fish, tolerate this phenomenon. However, animals with polyploid cells face challenges in reproductive success. The aberrant meiotic process leads to predominantly aneuploid daughter cells, hindering the survival and propagation of organisms with such chromosomal irregularities.