i)

• Sexual reproduction includes crossing over of chromosomes which leads to variations.

• These variations are responsible for making the existing species better and healthier and then ultimately to evolution.

• Sexual reproduction could also lead to speciation which is the formation of new species from the pre-existing one.

• Since it involves 2 parents so, the offspring receive characteristics from both the parents. Also, it is a time-consuming process so it somehow controls the population explosion which could have been there due to asexual reproduction.

ii) After the 14th day of menstruation cycle, the egg is taken to the uterus where it waits for the sperm to reach and fertilize it.

Female receives sperms after sexual intercourse, sperms travel through the vagina and reaches the egg in the uterus and fertilize it. After fertilization zygote is formed. zygote divides and forms an 8 celled structure called blastocyst. This blastocyst attaches itself to the uterine wall by a process called implantation. From here it further divides and develops into a fetus and then ultimately into a baby.