Placeholder Image

Subtitles section Play video

  • 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.

There are lots of different ways to cook an egg.

Subtitles and vocabulary

Operation of videos Adjust the video here to display the subtitles

B1 UK hen egg chicken genetic information genetic joel

How To Make A Chicken | At-Bristol Science Centre

  • 74 5
    Vicky posted on 2015/06/07
Video vocabulary