In early July we published DNA explained, the first short documentary from BBC Knowledge & Learning series , a forthcoming project that aims to explore a large variety of subjects in engaging and accessible ways.
Today we have posted the second episode in the series, Pregnancy.
Self-study activity:
Watch the video and complete the blanks in the transcript with the missing words.
The activity is suitable for Intermedio 1 and Intermedio 2 students.
BBC Knowledge Explainer: Pregnancy from TellyJuice on Vimeo.
Each and every one of us began life as a single cell, no bigger than a full stop. From this we (1) ... into a human being made up of trillions of cells performing countless different functions. But how?
Pregnancy from conception to birth takes an average of forty weeks starting from the beginning of the mother’s last menstruation period. Development begins with fertilization when a sperm (2) ... with an egg to create a single cell called zygote. This cell holds immense potential. It is a shared genetic (3) ... from the mother and the father encoded in the genes of their combined DNA.
Over the next four days the zygote journeys down the fallopian tube to the uterus. On the way, it divides, eventually forming a cluster of cells called a blastocyst which has two distinct parts. One part will form the embryo. The other part will form the placenta, which (4) ... it. The blastocyst arrives in the uterus and within two days the cells sink in and attach to the uterine wall to continue their development.
By four weeks the embryo consists of three (5) ... that will become the baby’s organs and tissues. The ectoderm will become the central nervous system, the brain and spine. The mesoderm gives rise to deep structures, the (6) ... , cartilage and bones, and the endoderm could form blood cells and the intestines.
At around five weeks a heart beat can be detected. (6) ... begin to form, and small swellings called limb buds show where the legs and arms are growing. From eight weeks, the organs, nerves and muscles are all in place. The embryo is now referred to as the foetus.
At around ten weeks the face is taking shape and the foetus is recognizably human. Between eleven and fourteen weeks finger nails, toe nails and unique fingerprints are beginning to form. Between fifteen and twenty-six weeks the foetus begins to react to loud sounds. It is now possible to tell whether it is a boy or a girl.
Between twenty-six and thirty-six weeks the foetus will begin to react to life and to develop a (7) ... cycle. The lungs and and nerve system have matured to the point where the foetus has a good chance of survival if it is born prematurely. From now the foetus starts to put on weight very rapidly, growing (8) ... deposits under the skin, ready for life outside the womb.
From thirty-seven weeks the baby is full term and maybe be born at any time. By now, the baby is usually head down, so that they can (9) ... into the mother’s pelvis. Eventually the mother’s uterine (6) ... start to contract. The cervix shortens and opened and the baby makes its journey down to the birth canal and into the world. It is the start of its life as a physically separate being, a baby with trillions of specialized cells, and it all began from just one.
Key:
1 developed 2 merges 3 inheritance 4 nourishes 5 layers 6 muscles 7 sleep 8 fat 9 descend
