1 Review What are chromosomes Compare and Contrast How does the

structure of chromosomes differ in prokaryotes and eukaryotes

2 Review What happens during each of the four phases of mitosis- write one or two sentences about each

Predict What do you think would happen if the spindle fibers were disrupted during metaphase

CH 10 CELL GROWTH AND DIVISION

10.2 The Process of Cell Division

Chromosomes

Carries and passes on genetic information from one generation to another

Each cell must copy its genetic information before cell division begins

Each daughter cell gets its own copy Different organisms have different

number of chromosomes.

Prokaryotic Chromosomes

Most prokaryotes contain a single, circular chromosome

Located in the cytoplasm (no nucleus).

Eukaryotic Chromosomes

Located in the nucleus Made up of chromatin

DNA and histone proteins.

Eukaryotic Chromosomes

Chromatin is DNA and histone proteins.

Eukaryotic Chromosomes

DNA coils around histones to make nuclesome.

Eukaryotic Chromosomes

Nucleosomes coil and form supercoils that form chromosomes.

The Prokaryotic Cell Cycle

Regular pattern of growth, DNA replication, and cell division

Binary fission Asexual reproduction Two genetically identical

cells are produced.

The Eukaryotic Cell Cycle

G1, S, G2, and M Interphase is G1, S,

and G2.

G1 Phase: Cell Growth

Cells increase in size and synthesize new proteins and organelles.

S Phase: DNA Replication

New DNA is synthesized (chromosomes are replicated).

G2 Phase: Preparing for Cell Division Organelles and

molecules are produced.

M Phase: Cell Division

Mitosis Division of the cell

nucleus Cytokinesis

Division of the cytoplasm.

Cell Structures Involved in Mitosis

Chromatid Each strand of a duplicated chromosome

Centromere Area where each pair of chromatids is joined

Centrioles Tiny structures in cytoplasm of animal cells

that help organize the spindle Spindle

Fanlike microtubule structure that helps separate the chromatids.

Mitosis

Prophase Metaphase Anaphase Telophase.

Prophase

Chromosome condense and become visible.

Prophase

Chromosome condense and become visible

Centrioles move to opposite sides.

Prophase

Chromosome condense and become visible

Centrioles move to opposite sides

The spindle forms.

Prophase

Chromosome condense and become visible

Centrioles move to opposite sides

The spindle forms Nucleolus

disappears and nuclear envelope breaks down.

Metaphase

Chromosomes line up across the center of the cell.

Metaphase

Chromosomes line up across the center of the cell

Spindle fibers connect the centromere.

Anaphase

The chromatids separate

Chromosomes are pulled to opposite ends.

Telophase

Chromosomes arrive at poles

Nuclear envelope reforms

Spindle breaks apart.

Animal Cytokinesis

Cell membrane is drawn in until the cytoplasm is pinched into two equal parts containing its own nucleus and organelles.

Plant Cytokinesis

Cell plate forms between the divided nuclei

Forms into a cell membranes Cell wall created between the

membranes.