Final answer:
The collective term for the products of fertilization, including the embryo or fetus, placenta, and embryonic membranes, is the conceptus. Thus, the correct answer to the question is 4) Conceptus.
Step-by-step explanation:
All the products of fertilization, including the embryo or fetus, the placenta, and the embryonic membranes, are collectively called the conceptus. This term encompasses all structures that develop from the zygote following fertilization and are meant to support and protect the growing embryo or fetus. During the initial stages, a zygote undergoes several cleavages to form a morula, and as it implants into the uterine wall, it forms into a blastocyst, eventually developing the placenta and embryonic membranes necessary for fetal development such as the amnion, yolk sac, allantois, and chorion.
Therefore, the correct answer to the question is 4) Conceptus. It's important to note that gametes are the haploid cells that fuse to form a zygote, the zygote is the initial diploid cell resulting from fertilization, and the embryo is the early developmental stage following the blastocyst stage and lasting until the end of the eighth week of gestation, when the term fetus is then used.