The following steps describe how a pregnancy begins. Put the steps in the correct order. Step 1: Sperm cells enter the vagina. Step 2: Sperm cells swim through the female reproductive system to meet an egg. Step 3: The fertilised egg implants into the uterus lining. Step 4: The nucleus of the sperm cell fuses with the nucleus of the egg cell. Step 5: The fertilised egg travels along the oviduct to the uterus.
Answer (1)
To understand how a pregnancy begins, it's important to know the process in detail. Here are the steps in the correct order:
Sperm cells enter the vagina.
This is the initial step where sperm cells are introduced into the female reproductive system, typically through ejaculation during sexual intercourse.
Sperm cells swim through the female reproductive system to meet an egg.
After entering the vagina, sperm cells travel through the cervix and into the uterus. They continue into the fallopian tubes, where they seek out an egg to fertilize.
The nucleus of the sperm cell fuses with the nucleus of the egg cell.
Once a sperm cell successfully reaches an egg, their nuclei fuse in a process called fertilization. This results in the formation of a zygote, which is the first cell of a new organism.
The fertilised egg travels along the oviduct to the uterus.
After fertilization, the zygote begins dividing and developing as it moves through the oviduct (also known as the fallopian tube) towards the uterus.
The fertilised egg implants into the uterus lining.
The final step involves the fertilized egg, now called a blastocyst, implanting itself into the lining of the uterus. This implantation is crucial for establishing a pregnancy, as it allows the developing embryo to receive nutrients and support from the mother's body.
This entire process is essential for the beginning of a pregnancy, taking place over the course of several days following fertilization.
