Final answer:
In an organism with a diploid chromosome number of 56, during meiosis, 28 bivalents and 28 tetrads are expected to form, as each bivalent also constitutes a tetrad during this process.
Step-by-step explanation:
The process of meiosis in organisms with diploid cells involves the pairing up of homologous chromosomes to form structures known as bivalents or tetrads during Prophase I - this is where they exchange genetic material.
In the newly-discovered organism Yawle nhoj, which has a diploid chromosome number of 56, this means that we would expect to see half of this number forming paired structures. Each pair (bivalent) consists of two chromosomes (four chromatids), which is also referred to as a tetrad because it has four chromatids. So, for an organism with 56 chromosomes, there would be 28 bivalents: each chromosome pairs with its homologous partner. Likewise, each of these bivalents is also a tetrad during meiosis.
Therefore, the correct answer to the number of bivalents and tetrads that would be expected to form during meiosis would be 28 bivalents and 28 tetrads (option "d").