Video Transcript
The figure shows the front view of the female reproductive system. Where does fertilization usually take place? (A) C, (B) A, (C) B, (D) D, (E) E.
To answer this question, let’s recall what we know about the female reproductive
system and how this anatomy is important in fertilization.
To review the female reproductive system, let’s start with naming the structure that
stores immature egg cells and reviewing its function. Immature egg cells are stored in the ovaries, which are indicated by letter E in the
diagram. The ovaries are endocrine glands that secrete a number of hormones, including
estrogen and progesterone, which help control the menstrual cycle. Each ovary is connected to the uterus by tubes called the fallopian tubes or
oviducts, which are indicated by the letter C in the diagram.
When egg cells mature, they are released from the ovary into the fallopian tubes. The fallopian tubes are where fertilization will occur if a sperm is able to travel
through the female reproductive system and fuse with a mature egg cell. If fertilization occurs, the zygote, which is a diploid cell formed from the fusion
between a mature egg cell and a sperm cell, will implant into the uterus, which is
indicated by the letter B in the diagram.
In the uterus, the zygote will divide and increase its number of cells. It will then develop into an embryo and then a fetus. The uterus, which is normally about the size of a pear, can stretch to be almost 500
times its size to accommodate the growing fetus. This growth and development period is called pregnancy, and it lasts around nine
months in humans. Pregnancy ends in birth when the fetus is pushed through the cervix and out the
vagina.
The cervix, which is indicated by the letter A in the diagram, is the narrow opening
that connects the uterus to the vaginal canal. The vagina, which is indicated by letter D in the diagram, is the muscular tube that
leads from the cervix to the external genitalia. The vagina is the final part of the female reproductive system traversed by the
developed fetus during birth. So in order for sperm to fertilize an egg, it must enter through the vagina and
travel through the female reproductive system to the fallopian tubes.
Now that we have reviewed what we know about the female reproductive system and how
this anatomy is important in fertilization, we can answer the question. Fertilization usually takes place in the fallopian tubes, which is indicated by the
letter C in the diagram.
