In which structure would a zygote occur in within the
female reproductive system

Sexual fertilization takes place when a sperm from the male fuses into the egg cell of the female. Human cells contain 23 chromosomes and has a total of 46 pairs of chromosomes. A male has a total of 46 pairs chromosomes and gives 23 chromosomes while a female has a total of 46 pairs of chromosomes and gives 23 chromosomes to the offspring. These pairing are responsible to the trait of the offspring. The formation of both male and female gametes creates a zygote. They will start to form at the fallopian tube, down to the oviduct and into the uterus as it continues to divide. 

When you are making a guess you are forming a hypothesis

Very hard to understand