1
00:00:00,000 --> 00:00:00,410


2
00:00:00,410 --> 00:00:03,900
Where we left off after the
meiosis videos is that we had

3
00:00:03,900 --> 00:00:04,960
two gametes.

4
00:00:04,960 --> 00:00:07,110
We had a sperm and an egg.

5
00:00:07,110 --> 00:00:08,350
Let me draw the sperm.

6
00:00:08,350 --> 00:00:11,790
So you had the sperm and
then you had an egg.

7
00:00:11,790 --> 00:00:14,810
Maybe I'll do the egg in
a different color.

8
00:00:14,810 --> 00:00:18,700
That's the egg, and we all
know how this story goes.

9
00:00:18,700 --> 00:00:20,390
The sperm fertilizes the egg.

10
00:00:20,390 --> 00:00:23,490
And a whole cascade of events
start occurring.

11
00:00:23,490 --> 00:00:27,060
The walls of the egg then become
impervious to other

12
00:00:27,060 --> 00:00:30,190
sperm so that only one sperm can
get in, but that's not the

13
00:00:30,190 --> 00:00:31,120
focus of this video.

14
00:00:31,120 --> 00:00:35,300
The focus of this video is how
this fertilized egg develops

15
00:00:35,300 --> 00:00:38,840
once it has become a zygote.

16
00:00:38,840 --> 00:00:42,920
So after it's fertilized, you
remember from the meiosis

17
00:00:42,920 --> 00:00:48,680
videos that each of these were
haploid, or that they had--

18
00:00:48,680 --> 00:00:51,570
oh, I added an extra i there--
that they had half the

19
00:00:51,570 --> 00:00:56,450
contingency of the DNA.

20
00:00:56,450 --> 00:01:00,685
As soon as the sperm fertilizes
this egg, now, all

21
00:01:00,685 --> 00:01:03,260
of a sudden, you have
a diploid zygote.

22
00:01:03,260 --> 00:01:04,099
Let me do that.

23
00:01:04,099 --> 00:01:07,160
So now let me pick
a nice color.

24
00:01:07,160 --> 00:01:10,620
So now you're going to have a
diploid zygote that's going to

25
00:01:10,620 --> 00:01:16,570
have a 2N complement of the DNA
material or kind of the

26
00:01:16,570 --> 00:01:20,320
full complement of what a normal
cell in our human body

27
00:01:20,320 --> 00:01:25,320
would have. So this is diploid,
and it's a zygote,

28
00:01:25,320 --> 00:01:30,030
which is just a fancy way of
saying the fertilized egg.

29
00:01:30,030 --> 00:01:31,570
And it's now ready
to essentially

30
00:01:31,570 --> 00:01:33,390
turn into an organism.

31
00:01:33,390 --> 00:01:36,570
So immediately after
fertilization, this zygote

32
00:01:36,570 --> 00:01:39,470
starts experiencing cleavage.

33
00:01:39,470 --> 00:01:42,620
It's experiencing mitosis,
that's the mechanism, but it

34
00:01:42,620 --> 00:01:44,170
doesn't increase
a lot in size.

35
00:01:44,170 --> 00:01:48,860
So this one right here will then
turn into-- it'll just

36
00:01:48,860 --> 00:01:52,030
split up via mitosis
into two like that.

37
00:01:52,030 --> 00:01:55,280
And, of course, these are each
2N, and then those are going

38
00:01:55,280 --> 00:02:01,510
to split into four like that.

39
00:02:01,510 --> 00:02:05,920
And each of these have the same
exact genetic complement

40
00:02:05,920 --> 00:02:08,750
as that first zygote, and
it keeps splitting.

41
00:02:08,750 --> 00:02:14,930
And this mass of cells, we can
start calling it, this right

42
00:02:14,930 --> 00:02:17,455
here, this is referred
to as the morula.

43
00:02:17,455 --> 00:02:20,550


44
00:02:20,550 --> 00:02:22,910
And actually, it comes from the
word for mulberry because

45
00:02:22,910 --> 00:02:24,250
it looks like a mulberry.

46
00:02:24,250 --> 00:02:26,930
So actually, let me just kind
of simplify things a little

47
00:02:26,930 --> 00:02:28,450
bit because we don't
have to start here.

48
00:02:28,450 --> 00:02:29,700
So we start with a zygote.

49
00:02:29,700 --> 00:02:32,240


50
00:02:32,240 --> 00:02:33,215
This is a fertilized egg.

51
00:02:33,215 --> 00:02:38,080
It just starts duplicating via
mitosis, and you end up with a

52
00:02:38,080 --> 00:02:40,860
ball of cells.

53
00:02:40,860 --> 00:02:43,680
It's often going to be a power
of two, because these cells,

54
00:02:43,680 --> 00:02:46,890
at least in the initial stages
are all duplicating all at

55
00:02:46,890 --> 00:02:48,230
once, and then you
have this morula.

56
00:02:48,230 --> 00:02:51,290


57
00:02:51,290 --> 00:02:54,850
Now, once the morula gets to
about 16 cells or so-- and

58
00:02:54,850 --> 00:02:56,550
we're talking about
four or five days.

59
00:02:56,550 --> 00:03:01,720
This isn't an exact process--
they started differentiating a

60
00:03:01,720 --> 00:03:04,510
little bit, where the outer
cells-- and this kind of turns

61
00:03:04,510 --> 00:03:05,450
into a sphere.

62
00:03:05,450 --> 00:03:08,880
Let me make it a little
bit more sphere like.

63
00:03:08,880 --> 00:03:12,650
So it starts differentiating
between-- let me make some

64
00:03:12,650 --> 00:03:13,380
outer cells.

65
00:03:13,380 --> 00:03:15,200
This would be a cross-section
of it.

66
00:03:15,200 --> 00:03:18,150
It's really going to look
more like a sphere.

67
00:03:18,150 --> 00:03:22,950
That's the outer cells and then
you have your inner cells

68
00:03:22,950 --> 00:03:24,980
on the inside.

69
00:03:24,980 --> 00:03:32,930
These outer cells are called
the trophoblasts.

70
00:03:32,930 --> 00:03:34,560
Let me do it in a
different color.

71
00:03:34,560 --> 00:03:40,896


72
00:03:40,896 --> 00:03:42,480
Let me scroll over.

73
00:03:42,480 --> 00:03:43,250
I don't want to go there.

74
00:03:43,250 --> 00:03:46,430
And then the inner cells, and
this is kind of the crux of

75
00:03:46,430 --> 00:03:48,550
what this video is all
about-- let me scroll

76
00:03:48,550 --> 00:03:49,450
down a little bit.

77
00:03:49,450 --> 00:03:54,530
The inner cells-- pick
a suitable color.

78
00:03:54,530 --> 00:04:01,590
The inner cells right there are
called the embryoblast.

79
00:04:01,590 --> 00:04:03,660
And then what's going to happen
is some fluid's going

80
00:04:03,660 --> 00:04:06,130
to start filling in some
of this gap between the

81
00:04:06,130 --> 00:04:08,790
embryoblast and the trophoblast,
so you're going

82
00:04:08,790 --> 00:04:14,160
to start having some fluid that
comes in there, and so

83
00:04:14,160 --> 00:04:18,029
the morula will eventually
look like this, where the

84
00:04:18,029 --> 00:04:21,480
trophoblast, or the outer
membrane, is kind of this huge

85
00:04:21,480 --> 00:04:22,760
sphere of cells.

86
00:04:22,760 --> 00:04:25,680
And this is all happening as
they keep replicating.

87
00:04:25,680 --> 00:04:29,620
Mitosis is the mechanism, so now
my trophoblast is going to

88
00:04:29,620 --> 00:04:34,680
look like that, and then
my embryoblast is going

89
00:04:34,680 --> 00:04:36,620
to look like this.

90
00:04:36,620 --> 00:04:46,160
Sometimes the embryoblast-- so
this is the embryoblast.

91
00:04:46,160 --> 00:04:51,320
Sometimes it's also called the
inner cell mass, so let me

92
00:04:51,320 --> 00:04:52,570
write that.

93
00:04:52,570 --> 00:04:56,450


94
00:04:56,450 --> 00:04:58,950
And this is what's going to
turn into the organism.

95
00:04:58,950 --> 00:05:01,390
And so, just so you know a
couple of the labels that are

96
00:05:01,390 --> 00:05:03,910
involved here, if we're dealing
with a mammalian

97
00:05:03,910 --> 00:05:07,710
organism, and we are mammals,
we call this thing that the

98
00:05:07,710 --> 00:05:10,690
morula turned into is a zygote,
then a morula, then

99
00:05:10,690 --> 00:05:13,720
the cells of the morula started
to differentiate into

100
00:05:13,720 --> 00:05:16,190
the trophoblast, or kind of the
outside cells, and then

101
00:05:16,190 --> 00:05:22,760
the embryoblast. And then you
have this space that forms

102
00:05:22,760 --> 00:05:26,960
here, and this is just fluid,
and it's called the

103
00:05:26,960 --> 00:05:28,210
blastocoel.

104
00:05:28,210 --> 00:05:32,510


105
00:05:32,510 --> 00:05:35,890
A very non-intuitive spelling
of the coel part of

106
00:05:35,890 --> 00:05:37,430
blastocoel.

107
00:05:37,430 --> 00:05:40,280
But once this is formed, this is
called a blastocyst. That's

108
00:05:40,280 --> 00:05:41,800
the entire thing right here.

109
00:05:41,800 --> 00:05:44,460
Let me scroll down
a little bit.

110
00:05:44,460 --> 00:05:49,870
This whole thing is called the
blastocyst, and this is the

111
00:05:49,870 --> 00:05:51,120
case in humans.

112
00:05:51,120 --> 00:05:54,070


113
00:05:54,070 --> 00:05:57,120
Now, it can be a very confusing
topic, because a lot

114
00:05:57,120 --> 00:05:59,940
of times in a lot of books on
biology, you'll say, hey, you

115
00:05:59,940 --> 00:06:02,580
go from the morula to
the blastula or the

116
00:06:02,580 --> 00:06:04,280
blastosphere stage.

117
00:06:04,280 --> 00:06:06,740
Let me write those words down.

118
00:06:06,740 --> 00:06:10,000
So sometimes you'll say morula,

119
00:06:10,000 --> 00:06:11,250
and you go to blastula.

120
00:06:11,250 --> 00:06:14,400


121
00:06:14,400 --> 00:06:15,760
Sometimes it's called
the blastosphere.

122
00:06:15,760 --> 00:06:20,120


123
00:06:20,120 --> 00:06:22,550
And I want to make it very
clear that these are

124
00:06:22,550 --> 00:06:25,630
essentially the same stages
in development.

125
00:06:25,630 --> 00:06:28,860
These are just for-- you know,
in a lot of books, they'll

126
00:06:28,860 --> 00:06:32,100
start talking about frogs or
tadpoles or things like that,

127
00:06:32,100 --> 00:06:33,440
and this applies to them.

128
00:06:33,440 --> 00:06:35,890
While we're talking about
mammals, especially the ones

129
00:06:35,890 --> 00:06:38,330
that are closely related
to us, the stage is the

130
00:06:38,330 --> 00:06:41,240
blastocyst stage, and the real
differentiator is when people

131
00:06:41,240 --> 00:06:44,360
talk about just blastula
and blastospheres.

132
00:06:44,360 --> 00:06:47,290
There isn't necessarily this
differentiation between these

133
00:06:47,290 --> 00:06:51,480
outermost cells and these
embryonic, or this

134
00:06:51,480 --> 00:06:54,290
embryoblast, or this inner
cell mass here.

135
00:06:54,290 --> 00:06:57,350
But since the focus of this
video is humans, and really

136
00:06:57,350 --> 00:06:59,620
that's where I wanted to start
from, because that's what we

137
00:06:59,620 --> 00:07:01,420
are and that's what's
interesting, we're going to

138
00:07:01,420 --> 00:07:03,810
focus on the blastocyst.

139
00:07:03,810 --> 00:07:06,310
Now, everything I've talked
about in this video, it was

140
00:07:06,310 --> 00:07:10,360
really to get to this point,
because what we have here,

141
00:07:10,360 --> 00:07:14,270
these little green cells that
I drew right here in the

142
00:07:14,270 --> 00:07:18,210
blastocysts, this inner cell
mass, this is what will turn

143
00:07:18,210 --> 00:07:19,200
into the organism.

144
00:07:19,200 --> 00:07:21,250
And you say, OK, Sal, if that's
the organism, what's

145
00:07:21,250 --> 00:07:24,980
all of these purple
cells out here?

146
00:07:24,980 --> 00:07:27,210
This trophoblast out there?

147
00:07:27,210 --> 00:07:30,880
That is going to turn into the
placenta, and I'll do a future

148
00:07:30,880 --> 00:07:34,595
video where in a human, it'll
turn into a placenta.

149
00:07:34,595 --> 00:07:35,970
So let me write that down.

150
00:07:35,970 --> 00:07:38,250
It'll turn into the placenta.

151
00:07:38,250 --> 00:07:41,600
And I'll do a whole future video
about I guess how babies

152
00:07:41,600 --> 00:07:44,320
are born, and I actually learned
a ton about that this

153
00:07:44,320 --> 00:07:47,580
past year because a baby
was born in our house.

154
00:07:47,580 --> 00:07:51,320
But the placenta is really
kind of what the embryo

155
00:07:51,320 --> 00:07:54,880
develops inside of, and it's the
interface, especially in

156
00:07:54,880 --> 00:07:59,260
humans and in mammals, between
the developing fetus and its

157
00:07:59,260 --> 00:08:02,220
mother, so it kind of is the
exchange mechanism that

158
00:08:02,220 --> 00:08:05,200
separates their two systems,
but allows the necessary

159
00:08:05,200 --> 00:08:06,790
functions to go on
between them.

160
00:08:06,790 --> 00:08:08,860
But that's not the focus
of this video.

161
00:08:08,860 --> 00:08:12,680
The focus of this video is the
fact that these cells, which

162
00:08:12,680 --> 00:08:15,870
at this point are-- they've
differentiated themselves away

163
00:08:15,870 --> 00:08:18,560
from the placenta cells, but
they still haven't decided

164
00:08:18,560 --> 00:08:20,540
what they're going to become.

165
00:08:20,540 --> 00:08:24,210
Maybe this cell and its
descendants eventually start

166
00:08:24,210 --> 00:08:27,640
becoming part of the nervous
system, while these cells

167
00:08:27,640 --> 00:08:31,540
right here might become muscle
tissue, while these cells

168
00:08:31,540 --> 00:08:36,750
right here might become
the liver.

169
00:08:36,750 --> 00:08:40,740
These cells right here are
called embryonic stem cells,

170
00:08:40,740 --> 00:08:43,120
and probably the first time in
this video you're hearing a

171
00:08:43,120 --> 00:08:45,440
term that you might recognize.

172
00:08:45,440 --> 00:08:48,220
So if I were to just take one of
these cells, and actually,

173
00:08:48,220 --> 00:08:52,890
just to introduce you to another
term, you know, we

174
00:08:52,890 --> 00:08:54,770
have this zygote.

175
00:08:54,770 --> 00:08:59,030
As soon as it starts dividing,
each of these cells are called

176
00:08:59,030 --> 00:09:00,930
a blastomere.

177
00:09:00,930 --> 00:09:04,020
And you're probably wondering,
Sal, why does this word blast

178
00:09:04,020 --> 00:09:08,210
keep appearing in this kind
of embryology video, these

179
00:09:08,210 --> 00:09:09,130
development videos?

180
00:09:09,130 --> 00:09:13,480
And that comes from the Greek
for spore: blastos.

181
00:09:13,480 --> 00:09:19,030
So the organism is beginning
to spore out or grow.

182
00:09:19,030 --> 00:09:21,610
I won't go into the word origins
of it, but that's

183
00:09:21,610 --> 00:09:23,030
where it comes from and that's
why everything has

184
00:09:23,030 --> 00:09:23,860
this blast in it.

185
00:09:23,860 --> 00:09:25,680
So these are blastomeres.

186
00:09:25,680 --> 00:09:28,970
So when I talk what embryonic
stem cells, I'm talking about

187
00:09:28,970 --> 00:09:34,330
the individual blastomeres
inside of this embryoblast or

188
00:09:34,330 --> 00:09:36,890
inside of this inner
cell mass.

189
00:09:36,890 --> 00:09:39,780
These words are actually
unusually fun to say.

190
00:09:39,780 --> 00:09:43,160
So each of these is an
embryonic stem cell.

191
00:09:43,160 --> 00:09:47,120
Let me write this down
in a vibrant color.

192
00:09:47,120 --> 00:09:52,190
So each of these right here are
embryonic stem cells, and

193
00:09:52,190 --> 00:09:53,440
I wanted to get to this.

194
00:09:53,440 --> 00:09:56,440


195
00:09:56,440 --> 00:09:58,530
And the reason why these are
interesting, and I think you

196
00:09:58,530 --> 00:10:00,760
already know, is that there's
a huge debate around these.

197
00:10:00,760 --> 00:10:03,830
One, these have the potential
to turn into anything, that

198
00:10:03,830 --> 00:10:05,950
they have this plasticity.

199
00:10:05,950 --> 00:10:07,410
That's another word that
you might hear.

200
00:10:07,410 --> 00:10:09,455
Let me write that down,
too: plasticity.

201
00:10:09,455 --> 00:10:12,050


202
00:10:12,050 --> 00:10:14,920
And the word essentially comes
from, you know, like a plastic

203
00:10:14,920 --> 00:10:17,130
can turn into anything else.

204
00:10:17,130 --> 00:10:19,630
When we say that something has
plasticity, we're talking

205
00:10:19,630 --> 00:10:21,780
about its potential
to turn into a lot

206
00:10:21,780 --> 00:10:22,620
of different things.

207
00:10:22,620 --> 00:10:26,380
So the theory is, and there's
already some trials that seem

208
00:10:26,380 --> 00:10:28,390
to substantiate this, especially
in some lower

209
00:10:28,390 --> 00:10:31,070
organisms, that, look, if you
have some damage at some point

210
00:10:31,070 --> 00:10:36,460
in your body-- let me
draw a nerve cell.

211
00:10:36,460 --> 00:10:40,590
Let me say I have a-- I won't
go into the actual mechanics

212
00:10:40,590 --> 00:10:43,790
of a nerve cell, but let's say
that we have some damage at

213
00:10:43,790 --> 00:10:46,980
some point on a nerve cell right
there, and because of

214
00:10:46,980 --> 00:10:50,450
that, someone is paralyzed
or there's some nerve

215
00:10:50,450 --> 00:10:51,400
dysfunction.

216
00:10:51,400 --> 00:10:54,330
We're dealing with multiple
sclerosis or who knows what.

217
00:10:54,330 --> 00:10:57,280
The idea is, look, we have these
cell here that could

218
00:10:57,280 --> 00:11:02,650
turn into anything, and we're
just really understanding how

219
00:11:02,650 --> 00:11:04,410
it knows what to turn into.

220
00:11:04,410 --> 00:11:06,550
It really has to look at its
environment and say, hey, what

221
00:11:06,550 --> 00:11:08,900
are the guys around me doing,
and maybe that's what helps

222
00:11:08,900 --> 00:11:10,150
dictate what it does.

223
00:11:10,150 --> 00:11:12,500
But the idea is you take these
things that could turn to

224
00:11:12,500 --> 00:11:16,740
anything and you put them where
the damage is, you layer

225
00:11:16,740 --> 00:11:19,910
them where the damage is, and
then they can turn into the

226
00:11:19,910 --> 00:11:21,510
cell that they need
to turn into.

227
00:11:21,510 --> 00:11:24,990
So in this case, they would
turn into nerve cells.

228
00:11:24,990 --> 00:11:29,220
They would turn to nerve cells
and repair the damage and

229
00:11:29,220 --> 00:11:32,480
maybe cure the paralysis
for that individual.

230
00:11:32,480 --> 00:11:35,640
So it's a huge, exciting area
of research, and you could

231
00:11:35,640 --> 00:11:37,700
even, in theory, grow
new organs.

232
00:11:37,700 --> 00:11:39,800
If someone needs a kidney
transplant or a heart

233
00:11:39,800 --> 00:11:43,690
transplant, maybe in the future,
we could take a colony

234
00:11:43,690 --> 00:11:44,980
of these embryonic stem cells.

235
00:11:44,980 --> 00:11:48,510
Maybe we can put them in some
type of other creature, or who

236
00:11:48,510 --> 00:11:52,050
knows what, and we can turn it
into a replacement heart or a

237
00:11:52,050 --> 00:11:52,660
replacement kidney.

238
00:11:52,660 --> 00:11:56,480
So there's a huge amount
of excitement about

239
00:11:56,480 --> 00:11:57,420
what these can do.

240
00:11:57,420 --> 00:12:01,310
I mean, they could cure a lot of
formerly uncurable diseases

241
00:12:01,310 --> 00:12:03,350
or provide hope for a
lot of patients who

242
00:12:03,350 --> 00:12:05,120
might otherwise die.

243
00:12:05,120 --> 00:12:07,870
But obviously, there's
a debate here.

244
00:12:07,870 --> 00:12:10,950
And the debate all revolves
around the issue of if you

245
00:12:10,950 --> 00:12:15,120
were to go in here and try to
extract one of these cells,

246
00:12:15,120 --> 00:12:17,560
you're going to kill
this embryo.

247
00:12:17,560 --> 00:12:21,160
You're going to kill this
developing embryo, and that

248
00:12:21,160 --> 00:12:23,670
developing embryo had
the potential to

249
00:12:23,670 --> 00:12:27,140
become a human being.

250
00:12:27,140 --> 00:12:28,880
It's a potential that obviously
has to be in the

251
00:12:28,880 --> 00:12:33,520
right environment, and it has
to have a willing mother and

252
00:12:33,520 --> 00:12:35,820
all of the rest, but it does
have the potential.

253
00:12:35,820 --> 00:12:40,370
And so for those, especially, I
think, in the pro-life camp,

254
00:12:40,370 --> 00:12:44,280
who say, hey, anything that has
a potential to be a human

255
00:12:44,280 --> 00:12:47,310
being, that is life and it
should not be killed.

256
00:12:47,310 --> 00:12:52,510
So people on that side of the
camp, they're against the

257
00:12:52,510 --> 00:12:54,510
destroying of this embryo.

258
00:12:54,510 --> 00:12:57,880
I'm not making this video to
take either side to that

259
00:12:57,880 --> 00:13:01,740
argument, but it's a potential
to turn to a human being.

260
00:13:01,740 --> 00:13:04,010
It's a potential, right?

261
00:13:04,010 --> 00:13:07,730
So obviously, there's a huge
amount of debate, but now, now

262
00:13:07,730 --> 00:13:10,310
you know in this video what
people are talking about when

263
00:13:10,310 --> 00:13:12,690
they say embryonic stem cells.

264
00:13:12,690 --> 00:13:14,680
And obviously, the next question
is, hey, well, why

265
00:13:14,680 --> 00:13:16,910
don't they just call them stem
cells as opposed to embryonic

266
00:13:16,910 --> 00:13:17,490
stem cells?

267
00:13:17,490 --> 00:13:20,875
And that's because in all of our
bodies, you do have what

268
00:13:20,875 --> 00:13:22,850
are called somatic stem cells.

269
00:13:22,850 --> 00:13:24,850
Let me write that down.

270
00:13:24,850 --> 00:13:29,000
Somatic or adults stem cells.

271
00:13:29,000 --> 00:13:30,100
And we all have them.

272
00:13:30,100 --> 00:13:32,860
They're in our bone marrow to
help produce red blood cells,

273
00:13:32,860 --> 00:13:36,160
other parts of our body, but the
problem with somatic stem

274
00:13:36,160 --> 00:13:41,780
cells is they're not as plastic,
which means that they

275
00:13:41,780 --> 00:13:44,810
can't form any type of cell
in the human body.

276
00:13:44,810 --> 00:13:46,880
There's an area of research
where people are actually

277
00:13:46,880 --> 00:13:50,470
maybe trying to make them more
plastic, and if they are able

278
00:13:50,470 --> 00:13:52,900
to take these somatic stem
cells and make them more

279
00:13:52,900 --> 00:13:56,290
plastic, it might maybe kill
the need to have these

280
00:13:56,290 --> 00:13:58,660
embryonic stem cells, although
maybe if they do this too

281
00:13:58,660 --> 00:14:01,690
good, maybe these will have
the potential to turn into

282
00:14:01,690 --> 00:14:03,010
human beings as well,
so that could

283
00:14:03,010 --> 00:14:04,770
become a debatable issue.

284
00:14:04,770 --> 00:14:08,130
But right now, this isn't an
area of debate because, left

285
00:14:08,130 --> 00:14:12,510
to their own devices, a somatic
stem cell or an adult

286
00:14:12,510 --> 00:14:15,420
stem cell won't turn into
a human being, while an

287
00:14:15,420 --> 00:14:19,760
embryonic one, if it is
implanted in a willing mother,

288
00:14:19,760 --> 00:14:21,970
then, of course, it will turn
into a human being.

289
00:14:21,970 --> 00:14:24,210
And I want to make one side
note here, because I don't

290
00:14:24,210 --> 00:14:30,410
want to take any sides on the
debate of-- well, I mean,

291
00:14:30,410 --> 00:14:31,250
facts are facts.

292
00:14:31,250 --> 00:14:33,900
This does have the potential
to turn into a human being,

293
00:14:33,900 --> 00:14:36,980
but it also has the potential
to save millions of lives.

294
00:14:36,980 --> 00:14:39,740
Both of those statements are
facts, and then you can decide

295
00:14:39,740 --> 00:14:42,960
on your own which side of that
argument you'd like to or what

296
00:14:42,960 --> 00:14:45,670
side of that balance you
would like to kind of

297
00:14:45,670 --> 00:14:47,210
put your own opinion.

298
00:14:47,210 --> 00:14:50,020
But there's one thing I want
to talk about that in the

299
00:14:50,020 --> 00:14:51,890
public debate is never
brought up.

300
00:14:51,890 --> 00:14:55,600
So you have this notion of when
you-- to get an embryonic

301
00:14:55,600 --> 00:14:58,570
stem cell line, and when I say
a stem cell line, I mean you

302
00:14:58,570 --> 00:15:00,880
take a couple of stem cells, or
let's say you take one stem

303
00:15:00,880 --> 00:15:04,550
cell, and then you put it in a
Petri dish, and then you allow

304
00:15:04,550 --> 00:15:06,650
it to just duplicate.

305
00:15:06,650 --> 00:15:09,780
So this one turns into two,
those two turn to four.

306
00:15:09,780 --> 00:15:12,380
Then someone could take one of
these and then put it in their

307
00:15:12,380 --> 00:15:13,600
own Petri dish.

308
00:15:13,600 --> 00:15:15,200
These are a stem cell line.

309
00:15:15,200 --> 00:15:20,310
They all came from one unique
embryonic stem cell or what

310
00:15:20,310 --> 00:15:21,950
initially was a blastomere.

311
00:15:21,950 --> 00:15:24,500
So that's what they call
a stem cell line.

312
00:15:24,500 --> 00:15:28,140
So the debate obviously is when
you start an embryonic

313
00:15:28,140 --> 00:15:31,060
stem cell line, you are
destroying an embryo.

314
00:15:31,060 --> 00:15:33,900
But I want to make the point
here that embryos are being

315
00:15:33,900 --> 00:15:37,140
destroyed in other processes,
and namely, in-vitro

316
00:15:37,140 --> 00:15:38,390
fertilization.

317
00:15:38,390 --> 00:15:40,530


318
00:15:40,530 --> 00:15:44,740
And maybe this'll be my next
video: fertilization.

319
00:15:44,740 --> 00:15:48,690
And this is just the notion that
they take a set of eggs

320
00:15:48,690 --> 00:15:49,515
out of a mother.

321
00:15:49,515 --> 00:15:52,430
It's usually a couple that's
having trouble having a child,

322
00:15:52,430 --> 00:15:54,280
and they take a bunch of
eggs out of the mother.

323
00:15:54,280 --> 00:15:56,940
So let's say they take
maybe 10 to 30

324
00:15:56,940 --> 00:15:59,000
eggs out of the mother.

325
00:15:59,000 --> 00:16:02,460
They actually perform a surgery,
take them out of the

326
00:16:02,460 --> 00:16:06,760
ovaries of the mother, and then
they fertilize them with

327
00:16:06,760 --> 00:16:09,890
semen, either it might come
from the father or a sperm

328
00:16:09,890 --> 00:16:13,210
donor, so then all of these
becomes zygotes once they're

329
00:16:13,210 --> 00:16:15,090
fertilized with semen.

330
00:16:15,090 --> 00:16:17,860
So these all become zygotes,
and then they allow them to

331
00:16:17,860 --> 00:16:19,870
develop, and they usually allow
them to develop to the

332
00:16:19,870 --> 00:16:21,480
blastocyst stage.

333
00:16:21,480 --> 00:16:25,600
So eventually all of these
turn into blastocysts.

334
00:16:25,600 --> 00:16:30,050
They have a blastocoel in
the center, which is

335
00:16:30,050 --> 00:16:32,520
this area of fluid.

336
00:16:32,520 --> 00:16:37,920
They have, of course, the
embryo, the inner cell mass in

337
00:16:37,920 --> 00:16:41,310
them, and what they do is they
look at the ones that they

338
00:16:41,310 --> 00:16:44,180
deem are healthier or maybe
the ones that are at least

339
00:16:44,180 --> 00:16:47,400
just not unhealthy, and they'll
take a couple of these

340
00:16:47,400 --> 00:16:50,160
and they'll implant these into
the mother, so all of this is

341
00:16:50,160 --> 00:16:52,180
occurring in a Petri dish.

342
00:16:52,180 --> 00:16:55,270
So maybe these four look good,
so they're going to take these

343
00:16:55,270 --> 00:16:57,840
four, and they're going to
implant these into a mother,

344
00:16:57,840 --> 00:17:01,070
and if all goes well, maybe one
of these will turn into--

345
00:17:01,070 --> 00:17:02,670
will give the couple a child.

346
00:17:02,670 --> 00:17:05,180
So this one will develop and
maybe the other ones won't.

347
00:17:05,180 --> 00:17:09,520
But if you've seen John & Kate
Plus 8, you know that many

348
00:17:09,520 --> 00:17:12,349
times they implant a lot of
them in there, just to

349
00:17:12,349 --> 00:17:14,520
increase the probability that
you get at least one child.

350
00:17:14,520 --> 00:17:17,310
But every now and then, they
implant seven or eight, and

351
00:17:17,310 --> 00:17:18,680
then you end up with
eight kids.

352
00:17:18,680 --> 00:17:21,150
And that's why in-vitro
fertilization often results in

353
00:17:21,150 --> 00:17:25,359
kind of these multiple
births, or reality

354
00:17:25,359 --> 00:17:27,270
television shows on cable.

355
00:17:27,270 --> 00:17:30,330
But what do they do with all
of these other perfectly--

356
00:17:30,330 --> 00:17:33,110
well, I won't say perfectly
viable, but these are embryos.

357
00:17:33,110 --> 00:17:36,350
They may or may not be perfectly
viable, but you have

358
00:17:36,350 --> 00:17:41,980
these embryos that have the
potential, just like this one

359
00:17:41,980 --> 00:17:42,680
right here.

360
00:17:42,680 --> 00:17:46,340
These all have the potential
to turn into a human being.

361
00:17:46,340 --> 00:17:50,730
But most fertility clinics,
roughly half of them, they

362
00:17:50,730 --> 00:17:52,950
either throw these away,
they destroy them, they

363
00:17:52,950 --> 00:17:54,040
allow them to die.

364
00:17:54,040 --> 00:17:56,690
A lot of these are frozen, but
just the process of freezing

365
00:17:56,690 --> 00:17:59,370
them kills them and then bonding
them kills them again,

366
00:17:59,370 --> 00:18:04,290
so most of these, the process of
in-vitro fertilization, for

367
00:18:04,290 --> 00:18:08,740
every one child that has the
potential to develop into a

368
00:18:08,740 --> 00:18:10,500
full-fledged human being, you're
actually destroying

369
00:18:10,500 --> 00:18:14,730
tens of very viable embryos.

370
00:18:14,730 --> 00:18:18,550
So at least my take on it is
if you're against-- and I

371
00:18:18,550 --> 00:18:21,750
generally don't want to take a
side on this, but if you are

372
00:18:21,750 --> 00:18:33,320
against research that involves
embryonic stem cells because

373
00:18:33,320 --> 00:18:36,580
of the destruction of embryos,
on that same, I guess,

374
00:18:36,580 --> 00:18:40,630
philosophical ground, you
should also be against

375
00:18:40,630 --> 00:18:47,360
in-vitro fertilization because
both of these involve the

376
00:18:47,360 --> 00:18:49,540
destruction of zygotes.

377
00:18:49,540 --> 00:18:52,520
I think-- well, I won't talk
more about this, because I

378
00:18:52,520 --> 00:18:54,320
really don't want to take sides,
but I want to show that

379
00:18:54,320 --> 00:18:56,850
there is kind of an equivalence
here that's

380
00:18:56,850 --> 00:19:00,755
completely lost in this debate
on whether embryonic stem

381
00:19:00,755 --> 00:19:02,920
cells should be used because
they have a destruction of

382
00:19:02,920 --> 00:19:04,980
embryos, because you're
destroying just as many

383
00:19:04,980 --> 00:19:08,000
embryos in this-- well, I won't
say just as many, but

384
00:19:08,000 --> 00:19:09,580
you are destroying embryos.

385
00:19:09,580 --> 00:19:12,720
There's hundreds of thousands of
embryos that get destroyed

386
00:19:12,720 --> 00:19:16,210
and get frozen and obviously
destroyed in that process as

387
00:19:16,210 --> 00:19:19,120
well through this in-vitro
fertilization process.

388
00:19:19,120 --> 00:19:22,010
So anyway, now hopefully you
have the tools to kind of

389
00:19:22,010 --> 00:19:25,140
engage in the debate around stem
cells, and you see that

390
00:19:25,140 --> 00:19:29,870
it all comes from what we
learned about meiosis.

391
00:19:29,870 --> 00:19:33,200
They produce these gametes.

392
00:19:33,200 --> 00:19:35,790
The male gamete fertilizes
a female gamete.

393
00:19:35,790 --> 00:19:39,510
The zygote happens or gets
created and starts splitting

394
00:19:39,510 --> 00:19:42,490
up the morula, and then it
keeps splitting and it

395
00:19:42,490 --> 00:19:45,730
differentiates into the
blastocyst, and then this is

396
00:19:45,730 --> 00:19:47,230
where the stem cells are.

397
00:19:47,230 --> 00:19:50,320
So you already know enough
science to engage in kind of a

398
00:19:50,320 --> 00:19:53,770
very heated debate.

399
00:19:53,770 --> 00:19:53,876