Final answer:
Meiosis in plant and animal life cycles produces haploid cells, gametes, and spores. Animals have a diploid-dominant cycle where gametes are the only haploid cells, while plants have an alternation of generations with both multicellular haploid and diploid stages.
Step-by-step explanation:
In the various life cycles of plant and animal life, the possible products of meiosis include haploid cells, gametes (sperm and egg cells), and spores. In animal life cycles, which are typically diploid-dominant, the only haploid cells produced are the gametes.
These gametes are produced via meiosis in specialized cells called germ cells. After fertilization, the zygote is formed, which is diploid, and this diploid state is maintained throughout the organism's life cycle until the next meiotic event.
In the life cycles of some algae and all plants, there is an alternation of generations. This includes both multicellular haploid and diploid phases. The multicellular haploid phase, known as the gametophyte, produces gametes through mitosis. Following fertilization, a diploid zygote is formed, which develops into a diploid multicellular plant called a sporophyte.
The sporophyte then produces haploid spores through meiosis, which grow into new gametophytes, completing the cycle. Thus, zygotes and somatic cells would generally not be direct products of meiosis but are rather intermediary or resultant stages in these life cycles.