From a single cell to a newborn, the story of how a baby is made is one of biology's greatest journeys.
Where does fertilisation of an egg by a sperm usually happen?
In the uterus
In the fallopian tube
In the ovary
In the cervix
Right! Sperm usually meet the egg in the outer part of a fallopian tube, and the embryo then travels to the uterus.
It's the fallopian tube. The egg is fertilised there, then the early embryo drifts to the uterus over several days.
How long can an egg typically be fertilised after ovulation?
About 5 days
About 72 hours
About 12 to 24 hours
About 2 weeks
Correct! An egg lasts only about 12 to 24 hours, though sperm can survive up to around 5 days.
It's about 12 to 24 hours. The 'fertile window' is longer only because sperm can survive up to about 5 days.
What decides whether a baby is genetically male or female?
The mother's egg
The timing of ovulation
The mother's hormones
The father's sperm
Yes! Every egg carries an X chromosome, while a sperm carries either an X or a Y.
It's the father's sperm. Eggs always carry an X; a sperm with a Y usually leads to a boy, one with an X to a girl.
Scratch the card to reveal a fact about babies
A baby girl is born with all the eggs she'll ever have, around one to two million.
What is the ball of cells called that implants in the uterus wall?
Blastocyst
Zygote
Foetus
Placenta
Correct! About a week after fertilisation, the blastocyst burrows into the uterine lining.
It's the blastocyst. The zygote is the single fertilised cell; it divides into a blastocyst that implants about a week later.
Which hormone do home pregnancy tests detect?
Progesterone
Oestrogen
hCG
Oxytocin
Right! hCG (human chorionic gonadotropin) is made by cells that form the placenta after implantation.
It's hCG. It's produced after implantation by future placenta cells, which is why tests work only after that.
Flip the card to reveal a fact about pregnancy
A baby's heart starts beating about five to six weeks into pregnancy, when the embryo is smaller than a pea.
Did you know?
Which organ develops during pregnancy to pass oxygen and food to the baby?
The amnion
The placenta
The yolk sac
The corpus luteum
Correct! The placenta links mother and baby, swapping oxygen, nutrients and waste without mixing their blood.
It's the placenta. It grows with the baby, connects via the umbilical cord, and is delivered after birth.
How long does a full-term pregnancy last, counted from the last period?
About 36 weeks
About 42 weeks
About 38 weeks
About 40 weeks
Yes! About 40 weeks from the last period, or roughly 38 weeks from conception.
It's about 40 weeks. Doctors count from the last period, about two weeks before conception.
From which week is the developing baby usually called a foetus?
Week 4
Week 9
Week 16
Week 20
Correct! From about the 9th week after conception, the main organs have formed and it is called a foetus.
It's around week 9 after conception. Before that it's an embryo, while the main organs are forming.
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What do babies practise in the womb?
Foetuses practise breathing, swallowing and even hiccupping long before birth.
Identical twins come from what?
Two eggs and two sperm
Two eggs and one sperm
One egg that split
One egg and two sperm
Right! Identical twins form when one fertilised egg splits, so they share the same genes.
They come from one fertilised egg that split. Fraternal twins come from two eggs fertilised by two sperm.
In IVF, where does fertilisation take place?
In a fallopian tube
In an incubator inside the body
In a laboratory dish
Correct! 'In vitro' means 'in glass': eggs are fertilised in a lab, then an embryo is placed in the uterus.
It's in a laboratory dish. IVF means 'in glass'; the embryo is later transferred into the uterus.
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Question 1: Where does fertilisation of an egg by a sperm usually happen?
Question 2: How long can an egg typically be fertilised after ovulation?
Question 3: What decides whether a baby is genetically male or female?
Question 4: What is the ball of cells called that implants in the uterus wall?
Question 5: Which hormone do home pregnancy tests detect?
Question 6: Which organ develops during pregnancy to pass oxygen and food to the baby?
Question 7: How long does a full-term pregnancy last, counted from the last period?
Question 8: From which week is the developing baby usually called a foetus?
Question 9: Identical twins come from what?
Question 10: In IVF, where does fertilisation take place?
Made with AI. This quiz was made with AI, which can make mistakes.
