Question

Fertilized ovum is transplanted in uterus after
A) 1 day
B) 7 days
C) 8 days
D)10 days

Answer 1

Hint: Fertilization is a process that takes place by the fusion of female and male gametes. It takes place in the fallopian tubes that connect the ovaries to the uterus.

Complete answer:
Fertilization is the fusion of male and female gametes that occurs in the fallopian tubes. It is doubtful that ovum attracts sperm. There are so many of them that will reach the fallopian tube. Sperm are motile and moving at a rate of 2mm per minute. The progress is slow and enters the uterine cavity 3-4 days later. The endometrium is under the influence of the corpus luteum and its glands are highly developed. They secreted actively. Implantation of the fertilized ovum occurs about 6-7 days after it has entered the uterine cavity i.e. 7-10 days after ovulation.
Thus, the correct answer is option B. i.e., 7 days.
Additional information: By the 8th day after fertilization, the fertilized egg or zygote has differentiated to form a complex structure. Its outside is covered with layers of cells that are called trophoblasts that are highly secretive enzymes which digest materials of the endometrium. The fertilized egg or zygote undergoes cleavage and thus forms the blastocyst.

Thus, the correct answer is option B. i.e., 7 days.

Note:The fertilized egg reaches the blastocyst stage and takes around 6-7 days. The zygote (i.e. single cell embryo) or fertilized egg at the stage of blastocyst gets implanted in the wall of the uterus after about 7 days of fertilization.