There is now a new career path called stool donor.

A donor.

That's the egg, and we all know how this story goes.

To show that donor children are all but human.

A friend, a donor.

In Germany, 12 percent check the box.

They actually perform a surgery, take them out of the ovaries of the mother, and then they fertilize them with semen, either it might come from the father or a sperm donor, so then all of these becomes zygotes once they're fertilized with semen.

Your donors are very lucky.

And this girl calls herself Tinker.

In the case of a male, these would be sperm cells.

Let me do that Y chromosome in a separate color.

And the gift of life has been extended from brain dead donors to living, related donors relatives who might donate an organ or a part of an organ,

So that's a gamete and this is a gamete.

And so what you're looking at here in donor one and donor four, which are the exceptions to the other two, that genes are being turned on in a very specific subset of cells.

The truth is, there are just simply not enough donor organs to go around.

Once I began working with my donors,

It's not just any cell in the body.

And this is where the system gets really interesting.

Just as an aside, this unification, this fertilization that occurred from this sperm cell to this egg cell, so it essentially penetrates into this egg cell and it creates this zygote, which is a fertilized egg cell from my mother, and this contains all DNA from both my father and my mother.

Well, the result has been very good.

And I'll draw the sperm much larger than it is normally relatively to the egg.

So that very first cell that was essentially my mom's egg fertilized by a sperm cell from my father, that was a zygote, and as soon as it's successfully fertilized, it has 2N, or it has the diploid number of chromosomes in the case of humans, which I believe I am one of them.

Difference human Neanderthal is sperm and testis, smell and skin.

There could've been 200 to 300 million other sperms in that race.

Where we left off after the meiosis videos is that we had two gametes.

They produce these gametes.

The fairy changed the prince into a cat.

And you need a sperm bank?

I'm in the operating room.

My father's sperm somehow met my mother's egg, and they fused.

Junko is quite familiar with English.

No need for birth control, Doc, are you sure about that?

John, John, I looked at your chart.

Let me draw the sperm.

Stuey, the hardest working PR guy. How's business?

In the name of the Father, the Son and the Holy Spirit.

So this very first cell that was created from this fertilized egg, this is called a zygote.

We had a sperm and an egg.

This one involves men.

So, for example on the left panel, top panel, you see a liver.

Well, I know I wouldn't have been a very good carer, but in a way I actually think I'm quite a good donor.

For each homologous pair, I'm either going to contribute the one that I got from my mother or the one that I got from my father, right?

We'll talk about how that happens when we talk about meiosis or mitosis, that when I generate my sperm cells, sperm cells essentially takes one instead of having 23 pairs of chromosomes in sperm, you only have 23 chromosomes.

The walls of the egg then become impervious to other sperm so that only one sperm can get in, but that's not the focus of this video.

And so it's a combination from my mother, so this is from my mother, and a sperm from my father.