What causes fertilization to occur?
genetic and an egg fuse
accumulation and an egg fuse
tissue and an egg fuse
sperm and an egg fuse
Many animals have a relatively simple life cycle. A general animal life cycle is shown in Figure below . Most animals spend the majority of their life as diploid organisms. Just about all animals reproduce sexually. Diploid adults undergo meiosis to produce sperm or eggs. Fertilization occurs when a sperm and an egg fuse. The zygote that forms develops into an embryo. The embryo eventually develops into an adult.