Chapter 3: Cell Division (Monday) http://player.discoveryeducation.com/index.cfm?guidAssetId=D007CB39-ABA0-429C-ABB8-1B70B3BD199A

Section 3.1: Cell division occurs in all organisms.

• DNA (deoxyribonucleic acid; de⋅ox⋅y⋅ri⋅bo⋅nu⋅cle⋅ic

ac⋅id) is the genetic material in cells, a chemical

that provides the cell with information for the

organism’s growth and repair. ([dee-ok-si-rahy-boh-noo-klee-ik)

• Fill in the frame game for DNA

1. made of two strands of molecules

2. a sketch of DNA strand

3. deoxyribonucleic acid

4. genetic material that contains information

for cell’s growth and function

Chromosomes are structures made of compacted

DNA. Chromosomes are made up of two pairs of

chromatids, held together near the center by

a structure called a centromere.

What is DNA & what are the two main parts of a

chromosome?

• Cell Division

• Cell Division is involved in growth,

development, and repair

In unicellular organisms functions of cell

division include reproduction

In multicellular organisms functions of cell

division include repair,

growth, and development,

Growth & Development

Describe how cell division makes growth,

development, and repair possible

new cells are produced as the body grows in size throughout life

as cells multiply, they become specialized for particular functions

Repair • When the body is injured, new cells are reproduced and cells divide to

replace old cells.

Cells in the lower layer new cell begin to fill the Cell stop their rapid

begin begin to divide and area as cells continue to once the break is

filled

What role does cell division play in healing the

body?

Break in skin

Dividing cells

New cells pushed up to fill cut

New cell layers

Wound is healed

Cells stop dividing

Section 3.2: Cell division is part of the cell cycle. http://player.discoveryeducation.com/index.cfm?guidAssetId=E674DE38-ED7E-407F-9678-EE48B04D417A

• Cell Cycle is the normal sequence of growth,

maintenance, and division in a cell.

The cell cycle includes three main parts:

Interphase, Mitosis, and Cytokinesis.

page 81: Cell Cycle

Fill in the word triangle diagram for

interphase

1. top row: a sketch of interphase

2. middle row: during interphase, the cell

grew to twice its original size

3. bottom row: interphase: the part of the

cell life cycle in which the cell grows

and performs life function

What is cytokinesis?

* occurs when a parent cell’s cytoplasm

divides after mitosis

• Interphase (1st)

Regular cell growth and functions

DNA is duplicated

• Mitosis (2nd)

Four phases of nucleus division.

• Cytokinesis (last)

The cytoplasm of the cell divides and two

identical cells are formed

Closure: Think pair share: (1) Explain a

cell cycle, including interphase and mitosis.

(2) What occurs in a life besides division?

Cell Division: Cell division produces two genetically identical cells

Steps of Mitosis

1. chromosmes form

2. chromosmes line up

3. chromosmes separate

4. nuclei form

• Before mitosis, the cell’s DNA is copy during

interphase

INTERPHASE

MITOSIS

The cell has grown and is ready to divide.

PROPHASE DNA condenses into chromosomes, each with two chromatids that are exact copies of each other.

METAPHASE Chromosomes line up in the middle of the cell.

ANAPHASE Chromosomes split into two chromatids and they are pulled to opposite sides.

CYTOKINESIS

• Cytokinesis differs in animal and plant cells

(bellwork)

animal cells have a cell membrane that form

around each cell.

plant cells have a cell plate that forms and

divides the two cells.

TELEPHASE New nuclear membrane forms and the cell begins to divide.

Two new cells are formed and are ready to begin the cell cycle again.

plant cells animal cells

Section 3.3: Both sexual and asexual reproduction involve

cell division. Tuesday

• Asexual reproduction occurs when an organism

produces one or more new organisms that are

identical to it self and that live independently of it.

Mitosis does not occur in asexual reproduction.

• Binary Fission is the form of asexual reproduction

occurring in prokaryotes. This process occurs when

the parent organism splits in two, producing two

completely independent daughter cells.

• Budding is a process in which and organism

develops tiny buds on its body. Each bud forms from

the parents’ cells, so the bud’s genetic material is the

same as the parents’. The bud grows until if forms a

complete or nearly complete new organism that is

genetically identical to the parent.

Yeast Cell

How is budding different in unicellular and

multicellular organisms?

• Regeneration is the process of new tissue growth

that occurs due to cell division. This process can

replace limbs that have been injured or removed, in

some organisms.

• Sexual Reproduction is the type of reproduction that

most multicellular organisms use.

It involves two parents

The offspring contain genetic material from two

parents