There are lots of different ways to cook an egg.
But what's the difference between the eggs you use to make your breakfast
and the eggs which make a chicken? To find the answer
we need to investigate the secrets life which start
with your genes.
All living things are made of cells, but to understand how to make a living thing
we need to look inside a cell.
So your body is made around 50 trillion cells. But in order to see
them we need to zoom in and study them on a microscopic scale.
So first of all, I need to take a swab of my own cheek cells
and then we're going to apply a blue dye
in order to see them. We've magnified this image by two hundred times
and if we look at this dark spot just here...
this is the nucleus of the cell, and this is what we can find something called chromosomes.
Chromosomes are made of DNA
which is divided into sections called genes.
These genes contain the instructions for living things
everything from making new cells to the colour of feathers.
To make an entire human
you need 23 pairs of chromosomes containing
20 thousand genes written in the language of DNA.
Different animals have different numbers have chromosomes
where we had 23 pairs a chicken has 39 pairs.
But what have chromosomes got to do with your breakfast?
So to tell us a little bit more I'm here with Joel and we've picked up some eggs
from the supermarket
but Joel is there any chance of these eggs having a chicken inside them?
So it's very low chance these eggs will have chickens inside them because
the hens that laid these eggs
will not been kept with the cockrels. Okay then, so how can we go about proving that?
So the definitive test will be to crack the egg open and to
take a look inside. All right, let's crack it open. So what are we looking for here?
So we're looking for something called the 'blastodisc' which is the small white
spot that we can see on the surface of the egg.
And what exactly is that? So this is where we find
half of the chromosomes - half the genetic information -
from the hen. So how would a hen go about getting
a full set of chromosomes and all of that genetic information?
So a hen would need to mate with a cockrel
and the cockrel's sperm would fuse with the
genetic information from the hen to fertilise the egg
we then have two sets of chromosomes. And the blastodisc is the point at which that
fertilisation actually happens? Yeah, so this is where fertilisation would
happen and this is where
the embryo - the actual chicken - would start to develop from that point.
In humans this development of the embryo
is called pregnancy and it happens inside the womb
over nine months. But in chickens this gestation period
takes place inside the egg over just three weeks.
And finally after that time you get a new life.
To unlock more secrets a biology check out Nerys dissecting a brain.
Stay tuned to our YouTube channel because next week we'll be running a live
stream it directly from the hatchery.
So if you'd like to see the chicks hatch for yourself, click subscribe.
Thanks for watching.