Question

A(n) __________ is a one-celled organism formed by the union of a sperm and an egg.

a. zygote blastocyst an. embryo
d. fetus

Answer 1

a. zygote

Step-by-step explanation:

This cell, formed by the union of an ovum and a sperm (Gr. zyg tos, yoked together), represents the beginning of a human being. The common expression 'fertilized ovum' refers to the zygote."

Answer 2

The answer to this question would be zygote as the is the first stage in the reproduction process. Then the zygote will go on to become an embryo which will then later develop into a fetus and finally a baby.