Mitosis How do your cells divide? Chapter 10 Why Do Cells Divide? Surface area Damaged cells Sex cells.

Mitosis

How do your cells divide?

Chapter 10

Why Do Cells Divide?

Surface area

Damaged cells

Sex cells

Cell Reproduction

is either sexual or asexual

Asexual Reproduction(one parent)

Binary Fission-

Budding

Vegetative Propagation

Regeneration

Advantages of Asexual Reproduction

Speed

Desirable Characteristics

Replacement

Division of the Cell 2. Cell division – the process by

which a cell divides into two new daughter cells.

3. Before cell division occurs, the cell replicates all it’s DNA giving each cell its own complete set of genetic information.

Chromosomes 4. The genetic information that is

passed from one generation of cells to the next is carried by chromosomes.

5. Chromosomes are made of DNA and protein.

C. At the beginning of cell division, each chromosome is replicated.

D. Each replicated chromosome consists of two chromatids attached at the centromere.

1. chromatid – one of two identical sister parts of a duplicated chromosome.

2. centromere – the area where the two chromatids are attached.

II. The Cell Cycle is made up of: A. Interphase – (G1, S, G2) the

period of growth between cell divisions.

B. Cell division

III. Events of the Cell Cycle (see Figure 10-4)

A. Interphase is divided into three phases:

1. G1 phase – period of activity in which cells do most of their growing.

2. S phase – chromosomes are replicated and the synthesis of DNA molecules take place.

3. G2 phase (shortest of the three) – many of the organelles and molecules required for cell division is produced.

.

B. When the events of G2 phase are completed, the cell enters M phase where mitosis and cytokinesis take place

Eukaryote cell division occurs in two stages: a. Mitosis – division of the cell nucleus. b.Cytokinesis – division of the cytoplasm.

The Cell Cycle

A Cell’s Life Cycle

When does a cell divide?

M

G1

S

G2

C

G1

Most of a cell’s life cycle is spent in Interphase when it performs normal life functions

6. After interphase, the cell enters mitosis which is the division of the nucleus.

Parent Cell

DNA condenses into chromosomes; Chromosomes attach to the spindle fibers

Chromosomes line up on the equator

Prophase

Metaphase

MITOSIS

Telophase DNA uncoils; 2 nuclei form

Anaphase Chromosomesseparate and are pulled to opposite ends

Cytokinesis- division of the cytoplasm

Cleavage (indention in cell membrane) or cell plate formation occurs.

Cell divides.

Animal Cell Plant Cell

Mitosis Animation

Overview of the Cell Cycle

InterphaseC ell G row th

an d R ep lica tion

M itosisN u c lear D ivis ion

CytokinesisC ytop lasm D ivis ion

Cell Cycle

It’s all about the chromosomes!10. There are 46 in human body

cells(23 pair)

– The number of chromosomes remain constant during Mitosis

Which Cells Go Through Mitosis?

Grow

Repair

Work

Cells which help the body The cells are called autosomes

12. What happens if cell division gets out of control?

CANCERThe body doesn’t respond

normally to the body’s control mechanisms

“Checkpoints”

Cell Cycle Regulators 13. Cyclin – proteins that

regulate the timing of the cell cycle in eukaryotic cells.

* Two types of regulatory proteins: internal regulators and external regulators.

1. Internal regulators – allow the cell cycle to proceed only when certain processes have happened inside the cell.

2. External regulators – direct cells to speed up or slow down the cell cycle.example – growth regulators

Bone Cancer X-ray

Ovarian Cancer Cell Dividing

14. Causes of cancer include smoking, tobacco, radiation exposure, and viral infection.

Skin Cancer

Mitosis Review

1. Is the beginning parent cell diploid or haploid ?

Diploid 2. Are the daughter cells diploid or haploid (2n or n)? Diploid

More Mitosis Review

3. How many daughter cells are produced? 2

4. Are the resulting daughter cells different from the parent cell? NO

More Mitosis Review

5. Are the resulting daughter cells different from each other? NO

6. How many chromosomes are in a human parent cell?

46Diploid or

Haploid? Diploid

7. How many chromosomes are in a human daughter cell?46

Diploid or Haploid?

Diploid

More Mitosis Review

7.What types of cells are produced by mitosis? Autosomes (body cells)

8. Why (when) does a cell go through mitosis? Growth, repair, make more cells

10.What is the name of the process? Mitosis

11.What are the names of the phases?

A. prophaseB. metaphaseC. anaphaseD. telophase

12. The cell labeled I is in what phase of the cell cycle?

interphase13. The nucleus is going

through process of mitosis and division of cytoplasm known as cytokinesis.