What happens if fertilisation does not take place?
The uterine lining builds-up in preparation for fertilization so that the zygote/embryo can implant itself into the uterine lining and then develop into a baby. Menstruation only takes place when fertilization doesn't take place, this occurs so the uterine lining is shed and can start a fresh next cycle so it can be ready for pregnancy again. If the uterine lining were to break down after fertilization a zygote/embryo wouldn't be able to implant itself…
How does the process of fertilization explain the need to have half the number of chromosomes in sex cells?
Otherwise, after fertilisation, the number of chromosomes would be doubled. Then, after each generation, the number of chromosomes would continue to be doubled! One might argue that after fertilisation, meiosis could take place, that is, the halving of the number of chromosomes could take place. It is true, but rare. Some organisms use this method.
Three functions of the female reproductive system are: Production of the Ova (female eggs) and transportation of Ova to site of fertilisation. Conception - Usually occurs in the fallopian tubes. This is the process where the female egg is fertilised by the male sperm. If fertilisation occurs, the female uterus provides an ideal safe environment for the baby to grow. (If fertilisation does not take place, menstruation occurs).