Name: ______________ Date: ________________

2. Cell Growth and Reproduction . S1-1-01 Illustrate and explain the process of mitotic cell division in plants and animals. Include: chromosomes,

mitosis, cytoplasmic division, cell cycle

. S1-1-02 Observe and explain the dynamic nature of cell division.

The Importance of Cell Division:

- Your SKIN is a protective layer of CELLS that covers your bones �and

organs.

- Cells are always DYING and have to be REPLACED.

- It has been found that 50% of all DUST in a FURNACE is dead �human

SKIN CELLS

- In order to replace these cells, they must REPRODUCE by �DIVIDING.

Cell Division:

ALL cells come from OTHER CELLS...NO EXCEPTIONS!

- All 100 trillion cells in your body came from one FERTILIZED EGG cell.

Functions of Cell Division:

1.REPLACEMENT CELLS:

- Every second, millions of your cells DIE, or are INJURED.

- The remaining cells must REPRODUCE or your body would �SHRINK

and DIE.

2. GROWTH:

- As the cells REPRODUCE, their numbers INCREASE, so your �SIZE

increases.

- All growth depends on CELL DIVISION.

�3. REPRODUCTION:

- When SINGLE-CELLED ORGANISMS divide, TWO NEW �organisms are

produced (eg. BACTERIA)

Million-Dollar Questions:

1.How do cells know WHEN to divide?

2.Why do cells divide RAPIDLY sometimes and SLOWLY others

(CALLUSES)?

3.Why do some cells always divide (BLOOD), and some rarely divide

(BRAIN)?

The Cell Cycle (Life of a Cell):

Cells can exist in one of two phases:

1. DIVIDING

- Very SHORT part of the

life of a cell - Called MITOSIS

2. NOT DIVIDING

- Very LONG part of the

life of a cell

- Called INTERPHASE

Interphase – A time for growth and repair:

During Interphase:

- Takes in NUTRIENTS.

- REPAIRS damaged parts

- GROWS rapidly

- Cell PREPARES for DIVISION by

DUPLICATING �CHROMOSOMES in

the NUCLEUS.

***Human cells go from 46 to 92 chromosomes during �interphase

- Chromosomes look like long STRINGS (SPAGHETTI) �

Mitosis & Cytokiniesis:

- In all cases of cell division, the MOTHER CELL divides into

TWO �DAUGHTER CELLS.

- CYTOKINESIS is the point where the cell SPLITS into two equal parts

Mitotic Cell Division:

MITOSIS has five different PHASES (STEPS). We will use an example of a

human cell going through mitosis

1. PROPHASE:

- LONG, thin CHROMOSOMES begin to SHORTEN and THICKEN.

- Nuclear membrane DISSOLVES

92 CHROMOSOMES are present (remember that they were

DOUBLED in INTERPHASE)

2. METAPHASE:

- The DOUBLE STRANDED CHROMOSOMES line up in the MIDDLE of

the cell

- SPINDLE FIBERS extend from CENTRIOLES

The cell still has 92 chromosomes.

3. ANAPHASE:

- Each chromosome SPLITS, and is pulled to opposite POLES (SIDES) of

the cell.

- This is the GENETIC MATERIAL provided to each DAUGHTER CELL.

46 chromosomes move to each SIDE (now SINGLE STRANDED)

4. TELOPHASE:

- New NUCLEAR MEMBRANE forms around each CHROMOSOME set.

- At the end of telophase, CYTOKINESIS begins…

…cell membrane PINCHES in.

- Two DAUGHTER CELLS with 46 CHROMOSOMES are formed.

Note: Cytokinesis is different in plant and animal cells:

In animal cells

- The cell membrane pinches in and forms a CLEAVAGE FURROW.

In plant cells

- A CELL PLATE forms to divide the cells

It is important to note that the whole cell cycle is CONTINUOUS (each phase FLOWS into the next).

- A cell goes through INTERPHASE, which flows into PROPHASE then

METAPHASE, ANAPHASE and TELOPHASE (MITOSIS).

- Once the new cells are formed, they are right back in INTERPHASE.

Remember: I P M A T I

Name: ______________ Date: ________________

2. Cell Growth and Reproduction . S1-1-01 Illustrate and explain the process of mitotic cell division in plants and animals. Include: chromosomes,

mitosis, cytoplasmic division, cell cycle

. S1-1-02 Observe and explain the dynamic nature of cell division.

The Importance of Cell Division:

- Your ______ is a protective layer of _________ that covers your

bones �and organs.

- Cells are always __________ and have to be _______________.

- It has been found that _______ of all ________ in a ____________ is

dead �human _________ ___________

- In order to replace these cells, they must ___________ by �_____________.

Cell Division:

_______ cells come from _________ __________...NO EXCEPTIONS!

- All 100 trillion cells in your body came from one _______________

______ cell.

Functions of Cell Division:

1.REPLACEMENT CELLS:

- Every second, millions of your cells _____, or are ___________.

- The remaining cells must ______________ or your body

would �_____________ and _________.

2. GROWTH:

- As the cells ____________, their numbers _____________, so

your �__________ increases.

- All growth depends on __________ _________________.

�3. REPRODUCTION:

- When ___________-___________ ______________ divide, __________ _________ �organisms are produced (eg. _______________)

Million-Dollar Questions:

1.How do cells know ____________ to divide?

2.Why do cells divide ___________ sometimes and ______________ others

(__________________)?

3.Why do some cells always divide (______________), and some rarely divide

(_______________)?

The Cell Cycle (Life of a Cell):

Cells can exist in one of two phases:

1. DIVIDING

- Very __________ part

of the life of a cell - Called

________________

2. NOT DIVIDING

- Very _________ part of

the life of a cell

- Called

________________

Interphase – A time for growth and repair:

During Interphase:

- Takes in ________________.

- _____________ damaged parts

- _____________ rapidly

- Cell ______________ for

_________________ by __________________ �__________________ in

the ____________________.

***Human cells go from ____ to ______ chromosomes during �interphase

- Chromosomes look like long ___________ (_________________) �

Mitosis & Cytokiniesis:

- In all cases of cell division, the _____________ ________ divides into

_____ �________________ __________.

- _____________________ is the point where the cell __________ into

two equal parts

Mitotic Cell Division:

______________ has five different __________ (_________). We will use an

example of a human cell going through mitosis

1. PROPHASE:

- __________, thin ______________ begin to _____________ and

________________.

- Nuclear membrane __________________

____ __________________ are present (remember that they were

________________ in ___________________)

2. METAPHASE:

- The _____________ ______________ ___________________ line up in the

__________________ of the cell

- _______________ ________________ extend from ____________________

The cell still has ____ chromosomes.

3. ANAPHASE:

- Each chromosome ____________, and is pulled to opposite _________

(___________) of the cell.

- This is the _____________ _____________ provided to each

_______________ ______________.

____ chromosomes move to each _______ (now _________ _____________)

4. TELOPHASE:

- New __________ _____________ forms around each ________________ set.

- At the end of telophase, _________________ begins…

…cell membrane ______________ in.

- Two _____________ ________ with ____ ___________________ are formed.

Note: Cytokinesis is different in plant and animal cells:

In animal cells

- The cell membrane pinches in and forms a ______________ ______________.

In plant cells

- A ________ _________ forms to divide the cells

It is important to note that the whole cell cycle is _________________ (each phase __________ into the next).

- A cell goes through ________________, which flows into ________________

then ________________, _______________ and _____________________ (__________________).

- Once the new cells are formed, they are right back in ____________________.

Remember: ____________________