- [Voiceover] Both mitosis and meiosis
- [Voiceover] Both mitosis and meiosis

are forms of cell division
are forms of cell division

that produce daughter cells containing genetic information
that produce daughter cells containing genetic information

from the parent cell.
from the parent cell.

Part a.
Part a.

Describe two events that are common
Describe two events that are common

to both mitosis and meiosis
to both mitosis and meiosis

that ensure the resulting daughter cells
that ensure the resulting daughter cells

inherit the appropriate number of chromosomes.
inherit the appropriate number of chromosomes.

All right.
All right.

So, really we just wanna,
So, really we just wanna,

well, what are two commonalities between the two?
well, what are two commonalities between the two?

Well, I can think of a bunch of them.
Well, I can think of a bunch of them.

You could start off saying,
You could start off saying,

well, DNA replicates before going into either of them.
well, DNA replicates before going into either of them.

So DNA replicates
So DNA replicates

before either,
before either,

before either.
before either.

You could say,
You could say,

well, the chromatin condenses into chromosomes
well, the chromatin condenses into chromosomes

in both of them.
in both of them.

Chromatin, chromatin
Chromatin, chromatin

condenses,
condenses,

condenses into,
condenses into,

into chromosomes.
into chromosomes.

You could talk about chromosomes form,
You could talk about chromosomes form,

getting aligned near the center of the cell,
getting aligned near the center of the cell,

attaching to, to, to fibers.
attaching to, to, to fibers.

You could talk about,
You could talk about,

we could talk about cytokinesis.
we could talk about cytokinesis.

Splitting the cells.
Splitting the cells.

So, cytokinesis,
So, cytokinesis,

kinesis involved,
kinesis involved,

involved in creation of separate cells.
involved in creation of separate cells.

Creation of separate,
Creation of separate,

separate cells.
separate cells.

In general the,
In general the,

your meiosis one has a lot of analogs
your meiosis one has a lot of analogs

with mitosis in general.
with mitosis in general.

You could keep looking,
You could keep looking,

keep digging deeper and listing more and more.
keep digging deeper and listing more and more.

They just want me to describe two events.
They just want me to describe two events.

I've already described three.
I've already described three.

Well, I'll leave it at that for now.
Well, I'll leave it at that for now.

In general, before you take the AP test,
In general, before you take the AP test,

mitosis and meiosis are good things to know in detail,
mitosis and meiosis are good things to know in detail,

because you might see questions like this
because you might see questions like this

on the free answer section,
on the free answer section,

or they're likely to show up
or they're likely to show up

in the multiple choice section as well.
in the multiple choice section as well.

But I think this is sufficient for part a.
But I think this is sufficient for part a.

We've described at least two events
We've described at least two events

that are common to both mitosis and meiosis.
that are common to both mitosis and meiosis.

If you have extra time,
If you have extra time,

you might try to list more.
you might try to list more.

And then part b.
And then part b.

The genetic composition of daughter cells
The genetic composition of daughter cells

produced by mitosis differs
produced by mitosis differs

from that of the daughter cells produced by meiosis.
from that of the daughter cells produced by meiosis.

Describe two features of the cell division process
Describe two features of the cell division process

that lead to these differences.
that lead to these differences.

Well, maybe the most obvious one,
Well, maybe the most obvious one,

the biggest difference between them,
the biggest difference between them,

is mitosis,
is mitosis,

mitosis involves one division,
mitosis involves one division,

involves one division.
involves one division.

Meiosis involves two.
Meiosis involves two.

Meiosis involves,
Meiosis involves,

involves, not inolves,
involves, not inolves,

involves, involves two.
involves, involves two.

This leads to
This leads to

two daughter cells
two daughter cells

from mitosis,
from mitosis,

and four daughter,
and four daughter,

daughter cells
daughter cells

from meiosis.
from meiosis.

Meiosis.
Meiosis.

That's a pretty big difference
That's a pretty big difference

between the two.
between the two.

Another big difference,
Another big difference,

and this is related to this.
and this is related to this.

Because,
Because,

because meiosis
because meiosis

has an extra division,
has an extra division,

has extra
has extra

division,
division,

but DNA
but DNA

replicates once,
replicates once,

like in, once,
like in, once,

like in mitosis,
like in mitosis,

the daughter cells from meiosis
the daughter cells from meiosis

have half the number of chromosomes.
have half the number of chromosomes.

They have a haploid number of chromosomes.
They have a haploid number of chromosomes.

The daughter
The daughter

cells
cells

in meiosis
in meiosis

have a haploid
have a haploid

number of chromosomes,
number of chromosomes,

number of
number of

chromosomes.
chromosomes.

Chromosomes.
Chromosomes.

So, and we could say,
So, and we could say,

mitosis daughters have diploid,
mitosis daughters have diploid,

daughters have diploid number.
daughters have diploid number.

And these are probably the two strongest differences.
And these are probably the two strongest differences.

But you could talk about other things.
But you could talk about other things.

You could talk about crossing over occurring in meiosis
You could talk about crossing over occurring in meiosis

but not in mitosis.
but not in mitosis.

You could talk about the separation
You could talk about the separation

and independent sortment
and independent sortment

of homologous chromosomes that you have.
of homologous chromosomes that you have.

Homologous, each member of a homologous pair
Homologous, each member of a homologous pair

that you have in meiosis
that you have in meiosis

that you don't have in mitosis.
that you don't have in mitosis.

So there's a bunch of things you could talk about.
So there's a bunch of things you could talk about.

And you could go into arbitrary detail.
And you could go into arbitrary detail.

It's nice that they only have to list two in each of these,
It's nice that they only have to list two in each of these,

in each of these parts of question four.
in each of these parts of question four.