LE CYCLE CELLULAIRE ET LA MITOSE POUR ÊTRE TRADUITS EN FRANÇAIS

PHA Biology 9

Moretti/ Dickson

DNA

Chromosomes: DNA tightly coiled around little protein balls (histones) to make it very compact

Gene: Instructions for making a protein that determines a trait

Another Gene: instructions for making a different protein that determines a different trait

Chromosome Review

Nucleotide Base Pairs

Chromosomes unraveling into DNA

DNA

Chromosomes: ADN étroitement enroulé autour de balles peu de protéines (histones) pour le rendre très compact

Gene: Instructions for making a protein that determines a trait

Another Gene: instructions for making a different protein that determines a different trait

Chromosome examen

Nucleotide Base Pairs

Chromosomes unraveling into DNA

Chromosome Review

Contain DNA Number varies

with organism: Humans: 46 Cats: 32 Dogs: 72

Note: Page 341 in Textbook has a good picture of karyotype

Objectives for Class:• Describe the structure of a chromosome.• Describe the purpose and the 4 major steps of the cell cycle.

The Cell Cycle: Overview

One cell grows and divides into two new cells

Purpose: Growth Replace dead cells Repair tissues

after injury Asexual

reproduction (in single-celled organisms)

Amoeba reproducing

Major Steps of the Cell Cycle

Interphase: growth; copying of chromosomes & organelles G1 phase: Cell grows S phase: DNA replicates G2 phase: More growth;

cell prepares to divide

M-Phase: Mitosis Chromosomes separate

to form two new nuclei Cytokinesis: Cell splits to form two new

identical cellsObjectives for Class:• Describe the structure of a chromosome.• Describe the purpose and the 4 major steps of the cell cycle.

Principales étapes du cycle cellulaire

Interphase: la croissance, la copie des chromosomes et les organites La phase G1: cellule croît Phase S: réplication de l'ADN Phase G2: Plus de croissance;

cellule se prépare à se diviser M-Phase:

Mitose chromosomes distinctspour former deux nouveaux noyaux

Cytocinèse: cellule se divise pour former deux nouvelles cellules identiques

Objectives for Class:• Describe the structure of a chromosome.• Describe the purpose and the 4 major steps of the cell cycle.

What do you notice about the chromosomes in G1 versus G2?

Objectives for Class:• Describe the structure of a chromosome.• Describe the purpose and the 4 major steps of the cell cycle.

Chromosome Replication During the Cell Cycle

G1 Phase: Chromosomes are un-

replicated - each contains one copy of its DNA

Un-Replicated Chromosome

G2 Phase: Chromosomes are replicated

- each contains two exact copies of its DNA

Centromere – a small spot in the center of a chromosome

Replicated Chromosome

Sister Chromatids– two halves of a replicated chromosome– exact copies of each other

Centromere

S Phase:DNA Replication

creates replicated chromosomes

Objectives for Class:• Describe the structure of a chromosome.• Describe the purpose and the 4 major steps of the cell cycle.

More Images of Chromosome Replication

Objectives for Class:• Describe the structure of a chromosome.• Describe the purpose and the 4 major steps of the cell cycle.

Why do Chromosomes Replicate?

So they can split during mitosis and separate into two new cells

Each cell gets an exact copy of each chromosome!

Objectives for Class:• Describe the structure of a chromosome.• Describe the purpose and the 4 major steps of the cell cycle.

Short Activity: Plant Cells in Mitosis Can you identify the different stages?

Objectives for Class:• Explain how mitosis separates the cell’s DNA into two different nuclei to create two new cells.

Mitosis: Chromosomes separate to form two new nuclei

Cytokinesis: Cell splits to form two new identical cells

M-Phase: Mitotic Division

Objectives for Class:Describe the purpose and steps of mitosis and cytokinesis.Draw diagrams showing how mitosis/cytokinesis separate chromosomes into two new cells.

• .

Stages of Mitosis

Step 1: Prophase

Step 2: Metaphase Step 4:

Telophase

Step 3: Anaphase

Animal Cell Plant Cells

Interphase

Objectives for Class:• Explain how mitosis separates the cell’s DNA into two different nuclei to create two new cells.

Mitosis begins (cell begins to divide) Spindle fibers form between the ends (poles) of

cell.

Mitosis Stages: Prophase

Objectives for Class:• Explain how mitosis separates the cell’s DNA into two different nuclei to create two new cells.

Mitosis Stages: Metaphase

Chromosomes line up at the center of the cell Spindle fibers attach to sister chromatids, as they

prepare to pull them apart

Objectives for Class:• Explain how mitosis separates the cell’s DNA into two different nuclei to create two new cells.

Chromatids (or pairs of chromosomes) separate and begin to move to opposite ends of the cell

Mitosis Stages: Anaphase

Objectives for Class:• Explain how mitosis separates the cell’s DNA into two different nuclei to create two new cells.

Two new nuclei form Chromosomes appear as chromatin (threads rather

than rods) Mitosis ENDS

Mitosis Stages: Telophase

Objectives for Class:• Explain how mitosis separates the cell’s DNA into two different nuclei to create two new cells.

Cell membrane moves inward to create two daughter cells – each with its own nucleus with identical chromosomes

Cytokinesis

Objectives for Class:• Explain how mitosis separates the cell’s DNA into two different nuclei to create two new cells.

Objectives for Class:• Explain how mitosis separates the cell’s DNA into two different nuclei to create two new cells.

Stages of Mitosis

Quiz Review: DNA Structure & Replication and the Cell Cycle

Schéma et décrire la structure de l'ADN et ...

Label les parties suivantes: le sucre désoxyribose Phosphate bases azotées des liaisons hydrogène.

Afficher bon appariement entre les bases azotées.

Définir chacun des termes suivants et expliquer

comment ils se rapportent tous à l'autre: ADN Les gènes Chromosomes Nucléotides Décrire les étapes de la

réplication de l'ADN.

Schéma et décrire la structure d'un chromosome. Dessiner un chromosome et l'étiquette

de la chromatides centromère et la sœur.

Distinguer entre les chromosomes non répliqués et reproduites.

Expliquer le résultat objectif et globale du cycle cellulaire.

Décrire ce qui se passe à chaque étape du cycle cellulaire: Interphase

Phase G1 Phase S Phase G2

Mitose Prophase Métaphase Anaphase Télophase Cytocinèse