Development of the human foetus

Define gestation and state its approximate duration in humans.
Describe some key stages of foetal development.
Identify and describe the functions of the placenta, umbilical cord, and fluid sac in supporting the developing foetus within the uterus.
Describe the main physical events that occur during the process of birth.

The journey from a fertilised egg to a newborn baby is a detailed process that happens in stages.
The time a baby spends developing in the uterus is called gestation. In humans, gestation lasts about 9 months from fertilisation to birth. This period allows a fertilised egg to grow and develop into a baby.
As the foetus grows, it goes through specific stages:
- 1 week: Cells start to divide and specialise.
- 4 weeks: The spine and brain begin to form, and the heart starts beating.
- 9 weeks: Tiny movements begin, and facial features like eyes and ears develop.
- 12 weeks: The foetus can swallow, kick, and practice breathing movements.
During pregnancy, mothers attend regular check-ups to monitor the baby's health. Doctors and midwives give advice on healthy habits, such as eating well, avoiding smoking, and not drinking alcohol, as these can affect the baby’s development.

The foetus grows inside the uterus, connected to the mother through important structures:
- Placenta: Transfers oxygen and nutrients from the mother to the foetus and removes waste from the foetus.
- Umbilical cord: Connects the foetus to the placenta.
- Fluid sac: Surrounds and protects the foetus from bumps.

At around 40 weeks, the baby is ready to be born.
The mother’s cervix opens, and muscles in the uterus contract to push the baby out through the vagina.
The umbilical cord remains attached to the baby until it is cut after birth.
The placenta is also delivered shortly afterward.

Gestation (Pregnancy): The period of time a baby develops inside the mother's uterus, lasting about 9 months in humans.
Uterus (Womb): The organ in the female body where a fertilised egg implants and develops into a baby.
Foetus: The term for the developing baby from about nine weeks after fertilisation until birth.
Placenta: An organ that develops in the uterus during pregnancy, providing oxygen and nutrients to the foetus and removing waste products.
Umbilical cord: A cord that connects the foetus to the placenta, containing blood vessels for transport.
Fluid sac (Amniotic sac): A membrane surrounding the foetus in the uterus, filled with amniotic fluid that protects the baby.
Birth: The process of the baby leaving the mother's body, usually around 40 weeks of gestation.

Investigate the importance of prenatal care, including a healthy diet and avoiding harmful substances like smoking and alcohol, for ensuring healthy foetal development during gestation.
Research and compare the gestation periods and birth processes of humans with those of other mammals, noting any significant differences.