Final answer:
The two types of gametes produced by multicellular eukaryotic organisms for sexual reproduction are sperm and ova, or eggs, which fuse to form a zygote.
Step-by-step explanation:
The two types of gametes typically produced by multicellular eukaryotic organisms are sperm and ova (or eggs).
In the process of sexual reproduction, multicellular eukaryotic organisms produce specialized haploid reproductive cells known as gametes through a type of cell division called meiosis. Gametes come in two forms - one is the male gamete, known as sperm, which is usually motile (able to move). The other is the female gamete, known as the ovum or egg, which is typically larger and non-motile (sessile). These gametes fuse during fertilization to form a zygote, which contains a mix of genetic material from each parent, leading to a genetically unique organism. This process of meiosis and fertilization introduces genetic diversity, contributing to the evolutionary success of sexually reproducing organisms. While the details can vary among different species, the fundamental concept of sexual reproduction involves the combination of these two distinct types of gametes.