Cell cylce and cell division, an introduction

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Introduction to cell cylce and cell division. Interphase (g1,s,g2) Mitotic phase (mitosis, cytokinesis) Meiosis, from diploid to aploid....

Transcript of Cell cylce and cell division, an introduction

INTRODUCTION TO CELL CYCLE AND CELL DIVISION

All organisms reproduce.

Reproduction has a cellular basis.

All cells come from pre-existing cells

Cell division enables living things to repair damage, grow and produce offspring

• Sexual reproduction, two parents are involved and the genetic material combines. Union of sex cells (egg and sperm).

• Some organisms reproduce by simple cell division (asexual reproduction). Ex. Paramecium (unicellular), and Sea stars (multicellular).

Cell division

Process by which a parent cell divides into two daughter cells.

Mitosis Meiosis

Each daughter cell is genetically identical to the parent cell.

Chromosomes in the daughter cell is reduced by

half

THE CELL CYCLE

Eukaryotic cells undergo a sequence of events known as the CELL CYCLE.

The cell cycle goes from the birth of a cells until it reproduces.

90% of the cell cycle in interphaseS phase 3-6 hours.

INTERPHASE

Duplication of chromosomes.

Cell increases supply of proteins

and # of many organelles.

Cell carries out metabolic processes

S DNA Synthesis.

G Gap.

Chromosomes are loosely packed as chromatine fibers.

G Gap.

Cell is ready for mitosis.

Mitotic phase

Includes 2 processes:

Mitosis

Cytokinesis.

Mitosis: Nucleus and chromosomes divide.

Cytokinesis: is the process by which the cytoplasm is divided in two.

Error in chromosome distribution is 1 in 100 000 cell divisions.

Centrioles are only present in animal cells.They help organize the microtubules.Self replicating

Cytokinesis in Animals and Plants

Concept check

1. Describe a significant event that occurs in each of the four stages of mitosis.2. Compare and contrast cytokinesis in animal and plant cells.3. In what sense may prophase and telophase in mitosis be characterized as opposites?

homework

Mitosis

Meiosis

Allele

Somatic Cells

Nucleus

G1 Phase

Interphase

G2 Phase

Chromatin

Research two different biological concepts for the following words indicating the source of each concept: