CELL DIVISIONCELL DIVISIONMITOSISMITOSISMEIOSISMEIOSIS

CONCEPT MAP:CONCEPT MAP:

CELL DIVISIONCELL DIVISIONGROUP 4GROUP 4

CELL DIVISION

UnderstandingMitosis

UnderstandingMeiosis

what

Producing new cells

Cell cycle

the need

definition

The significance

divides into

a part of

consists of

cytokinesis

mitosis

phases

includesstages

Controlled mitosis

Importance of

Uncontrolled mitosis

effects of

cancertumour

examples

consists ofAnimal cell & plant cell

Contributes to

regeneration

healing

examples

Compare & contrast

cloningapplication

Tissue culture

includes

Advantages & disadvantages

Chromosome movement

appreciates

Preventive measuresDisorderly movement Effects Leads to

Compare & contrast

Compare & contrast

what

definition

Maintain diploid number the need

The significance Contributes to

Where it occurs

relates to

stages

consists of

Meiosis I Meiosis II

divides into

hasincludes

WHY WE GROW UP?WHY WE GROW UP?

CONCEPT MAP:CONCEPT MAP:

CELL DIVISIONCELL DIVISION

GROUP 4GROUP 4

MITOSISMITOSIS

• As you know cell is a living thing. So, died cells must be change. This process we call it mitosis process. Cells divides for enhance the number of cells in our body or in organism. Mitosis are very important to replace and improve the damage cells. Generally, mitosis processes are liable to re consuming, replace a new cells, growing and asexual reproduction.

LET’S ENJOY WITHLET’S ENJOY WITH

•MITOSIS

CYCLE OF CELLCYCLE OF CELL

- G1

- S

- G2

- MITOSIS

- CYTOKINESIS

INTERPHASEINTERPHASE

• In the non-dividing Interphase cell, we have already learned that the chromosomes are extended so that their DNA can be used by the cells. Because of this, the chromosomes can not be seen in the nucleus.

• G1 (FIRST GROWING)• S (SYNTHESIS DNA)• G2 ( SECOND GROWING) - chromosomes

condense by re-coiling. there is a point when they finally become visible in the nucleus as they grow shorter and thicker. This is the beginning of Prophase.

MITOSIS HAVE 4 PHASEMITOSIS HAVE 4 PHASE

• PROPHASE

• METAPHASE

• ANAPHASE

• TELOPHASE

CYTOKINESISCYTOKINESIS

• PLANT CELL • ANIMAL CELL

PROPHASEPROPHASE

• Chromatin in the nucleus begins to condense and becomes visible in the light microscope as chromosomes.

• The nucleolus disappears. Centrioles begin moving to opposite ends of the cell and fibers extend from the centromeres.

• Some fibers cross the cell to form the mitotic spindle.

METAPHASEMETAPHASE• Proteins attach to the centromeres

creating the kinetochores. Microtubules attach at the kinetochores and the chromosomes begin moving.

• Spindle fibers align the chromosomes along the middle of the cell nucleus. This line is referred to as the metaphase plate. This organization helps to ensure that in the next phase, when the chromosomes are separated, each new nucleus will receive one copy of each chromosome.

ANAPHASEANAPHASE

• The paired chromosomes separate at the kinetochores and move to opposite sides of the cell. Motion results from a combination of kinetochore movement along the spindle microtubules and through the physical interaction of polar microtubules.

TELOPHASETELOPHASE• Chromatids arrive at

opposite poles of cell, and new membranes form around the daughter nuclei. The chromosomes disperse and are no longer visible under the light microscope. The spindle fibers disperse, and cytokinesis or the partitioning of the cell may also begin during this stage

CYTOKINESISCYTOKINESIS

• In animal cells, cytokinesis results when a fiber ring composed of a protein called actin around the center of the cell contracts pinching the cell into two daughter cells, each with one nucleus. In plant cells, the rigid wall requires that a cell plate be synthesized between the two daughter cells.

IN PLANT CELLIN PLANT CELL

- In plant cells, the rigid wall requires that a cell plate be synthesized between the two daughter cells.

IN ANIMAL CELLIN ANIMAL CELLIn animal cells, cytokinesis results when a fiber ring composed of a protein called actin around the center of the cell contracts pinching the cell into two daughter cells, each with one nucleus

QUESTIONSQUESTIONS

MEIOSISMEIOSIS

Prophase 1Prophase 1

• Choromosome condense and split into two kromatid.

• Each homologus pairs is now called bivalent or tetrad

• The pairing of the homologus chromosomes is called synapsis.

Prophase 1Prophase 1

• Chiasma are points where the exchange of chromatid is called crossing – over.

• Nuclear membrane disappears.

Metaphase 1Metaphase 1

• The nuclear membrane disappear and the spindle fibres are fully formed

• The homologous chromosomes or tetrads assemble on the equator of the spindle.

Anaphase 1Anaphase 1

• Choromosomes in each homologous pair (tetrad) separate, being pulled by the spindle fibres.

• Each pole receive only one of each homologous pair chromosomes

Telophase 1Telophase 1

• Chromosomes reach the opposite poles of the spindle and the spindle fibres disappear

• Cytokinesis occurs to produce two haploid cells

Meoisis 11Meoisis 11

• Divide the remaining set of chromosomes in a mitosis – like process

• No replication

QUESTIONSQUESTIONS

1. Which of the following 1. Which of the following features of cell division is features of cell division is very different for animal very different for animal

and plant cells? and plant cells? • A. prophase

• B. metaphase

• C. anaphase

• D. cytokinesis

2. The stage of the cell cycle 2. The stage of the cell cycle where the cell is preparing where the cell is preparing to begin DNA replication is to begin DNA replication is

called: called:

• A. G1

• B. G2

• C. S

• D. M

3. Name the stage of mitosis as 3. Name the stage of mitosis as shown in figure 1shown in figure 1

Figure 1Figure 1

A. ProphaseB. MetaphaseC. TelephaseD. Anaphase

4. The parts of X and Y are4. The parts of X and Y are

• X YA. Chromosome Sentromer

B Chromatid Centromer

C. Chromatin Centriol

D. Chromosome Centriol

5. The number of chromosome in 5. The number of chromosome in diploid cell arediploid cell are

A. 3

B. 6

C. 12

D. 24

6. Which the following cell doing 6. Which the following cell doing the mitosis?the mitosis?

• I. Skin• II. Meristem• III. Gamete• IV Cambium

A. I and II onlyB. I, II and III

onlyC. I, II and IV

onlyD. II, III and IV

only

meiosismeiosis

• Reduction division of diploid cells to produce haploid sex gametes.

• Take places at testes and ovaries, anthers and ovules.

Question 1All tumours are malignant. Circle the correct answer.

(True or False)

Question 2Cancer cells become dangerous when they disrupt the functions of

neighbouring cells. Circle the correct answer.(True or False)

Question 3Tumour is a mass of cancer cells. Circle the correct answer.

(True or False)

Question 4Tumour is a mass of undifferentiated cells. Circle the correct

answer.(True or False)

Question 5Elongation of the roots is controlled mitosis. Circle the correct

answer.(True or False)

Question 6Germination of seeds is controlled mitosis. Circle the correct

answer.(True or False)

QUESTIONSQUESTIONS

QUESTIONSQUESTIONS