Chapter 5 Cell Division 2003v

Biology…is about us

…is about living things

…is about animal

…is about plant

Do you remember…during form 1

You have learnt about …

Cell is basic unit of life

Now we will learn new topic

Do you ready to start our lesson?

5.1 Mitosis 5.2 Meiosis

5.3 Appreciating

Watch the video carefully...

Pea plant movie

What about this picture???

allStagesButtons.gif

This is we called as...development

• What process or even occur which allow all of these happen????

Cell divison

CHAPTER 5:

Today we will learn about

5.1 mitosis

The necessity for cell division in living organism

What is chromosome?

The significance of mitosis

The necessity for cell division in living organism

• All living organism consist of cell

– Most of cell undergo cell division

Cell Division- mitosis

...splitting cell into two daughter cell which genetically identical to parent cell

Parent cell

Daughter cell

Why do cells divide?

• _______

• _______• _______

• _______

The cell divide for...

• The new cell formation allow:• replacement of dead cell

• body repair damaged tissue

• body growth and development

• reproduction in unicellular organism

Types of cells

– Somatic cell- all body cell (except reproductive cell) form trough mitosis

– Gametic cell- reproductive cell that formed trough meiosis

What is chromosomes

• The nucleus of cell contain chromosomes

• Each chromosomes contain DNA molecules which carries genes (genetic material)

• Genes- determine the individual characteristic of organism

Number of chromosomes

• The chromosomal number for certain species is constant and varied from one species to another.

Eg: human - 46 chromosomes

• Monkey- 48 chromosomes• Chicken- 78 chromosomes

Somatic cell – has two set of chromosomes. One set is inherited from each parent.

Two set of chromosomes = diploid= 2n

Gametic cell – has one set of chromosomes.

One set of chromosome=_______=_____

Gametic cell – has one set of chromosomes.

One set of chromosome=_______=_____

Diploid organisms receive one of each type of chromosome from female parent (maternal chromosomes) and one of each type of chromosome from male parent (paternal chromosomes)

Ploidy – refers to the number of sets of homologous chromosomes in a cell

● ______ – one copy of each chromosome

– designated as “n”

● ______ – two copies (= pair) of each chromosome – designated as “2n”

• In human (46 chromosomes in somatic cell)• Each set consist of _____ chromosomes

• the nucleus of human somatic cell has ______ chromosomes arranged in _____ pairs or 2n = ______ chromosomes

• Gametes contain only one set of unpaired chromosomes or haploid number of chromosomes (n)

2set (2n-diploid): ___ chromosomes (somatic cell)1set (n-haploid):___ chromosomes (gametic cell)

Trivia....

• A monkey sperm cell have 24 chromosomes, how many pairs of chromosomes does the cheek cells of the monkey have?

Homologous chromosomes

• Two chromosomes in each pair have the same structural features and are referred as the homologous chromosomes.

Homologue

• One form paternal origin whereas the other one is from maternal origin

Homologous Chromosomes

Homologous vsDuplicated

Karyotype

Significances of mitosis

• Each daughter formed through mitosis carries genetic material (DNA) inherited from the parent cell.

• This genetic information is passed on to new cells during division to produce two identical nuclei.

The important of mitosis

1. growth- the number of cell within organism increases by mitosis. Basic grow in multi cellular organism

Growth in human

2. cell replacement- replacement damaged cells and tissue

• 3. Regeneration – some animals are able to regenerate whole part of the body such as star fish, lizard tail

• 4. asexual reproduction – mitosis is the basis of asexual reproduction individual of species by one parent

What you need to know about cell divisions?

• What happen before division?

• What is chromosome, centromer, centriole, sister chromatids and homologous chromosome?

Packing for the move…

When cell is not dividing… ● DNA molecules in extended, uncondensed form = __________

● Cell can only use DNA to produce molecules when in extended state.

When cell is preparing for division…

● DNA molecules condense to form ______________ prior to division.

– each chromosome is a single molecule of DNA

– easier to sort and organize DNA into daughter cells

Structure of a eukaryotic chromosome

• __________ chromosome

arm armcentromere

Prior to cell division:• chromosomes (DNA) are replicated (duplicated)

duplicatedchromosome

• duplicated chromosome – attached at their centromeres – as long as attached, known as _________ ______________

daughterchromosomes

sisterchromatids

Karyotype• Karyotype is the ______

______ ___ _________ of a cell of any living organism.

• The chromosomes are arranged and displayed (often on a photo) in pairs, ordered by size.

• To the right is a typical karyotype of a human male.

arm armcentromere

Karyotype

Haploid, Diplod, Homologous, Replicated, Duplicated, Chromatids, Chromosomes…

What do you understand about development??? What happen to cell?

What is cell division?

allStagesButtons.gif

Cell cycle

Cell Cycle

2 major phases:

• __________ (3 stages) – DNA uncondensed (= chromatin)

• ________ (4 stages + cytokinesis)- Nuclear division & division of cytoplasm

– DNA condensed (= chromosomes)

My idea

• Before we continue, I want all of you to draw the cell in interphase phase base on you understanding

Interphase

non-dividing state

3 sub-stages:

___ – cell grows in size – organelles replicated

___ – replication of DNA – synthesis of proteins associated with DNA

___ – synthesis of proteins associated with mitosis

My idea (2 minutes)

• Base on the cell given, draw the cell in each sub phase base on your understanding

Mitosis 4 sub-phases:

1st – Prophase

2nd – Metaphase

3rd – Anaphase

4th – Telophase and Cytokinesis

ACTIVITY: JIGSAW1. Teacher will count student from 1 until

5 then it will be repeating until all of student finish

2. then all of you will sit in group and get the subtopic to be discuss from teacher.

3. after finish discussion in group (10 min), you need to distribute into another group and explain about the subtopic you get until they understand.(5 min)

Stages in Mitosis

PROPHASE

• Chromosomes in the nucleus condense and become tightly coiled. They appear shorter and thicker

• Each chromosomes consist of a pair of sister chromatids joined together at the centromere.

Prophase:nucleus disappears

centrioles migrate

chromosomes appear

METAPHASE

• Begin when centromere of all chromosomes are line up on the metaphase plate

• Two sister chromatids are attached the fibres by their centromere.

centriole

centromereSister chromatids

Spindle fibre

ANAPHASE

• Two sister cromatids of each chromosomes separate at the centromere

• Sister chromatid are pulled apart to the opposite pole by the shortening of spindle fibre.

anaphase

TELOPHASE• Begin when 2 set of

chromosomes reach the opposite pole of the cell.

• The spindle fibre dissapear and a new cell membrane form around each set of chromosomes

• Nucleolus also form in each of nucleus

• Chromosomes start to uncoil (chromatin)

APPLY YOUR IDEASAPPLY YOUR IDEAS

1. Answer all the objective question (individually)

2. I will call a number to write down the answer in front of class.

Lets plaaaay…

“Guess That Phase!”

Activities (20 MINUTES)Activities (20 MINUTES)

• Made model of MITOSIS using drawing paper, thread and plasticine in group of 5

• The chromosome number is 2n=2

• Made sure your model has the 4 phase of mitosis and show the daughter cell at the last.

Summary-Phases and Sub-phases of Cell Division

1. Interphase

2. Mitosis

a. Nuclear division

b. Cytokinesis

1. Prophase

2. Metaphase

3. Anaphase

4. Telophase

DEMOs: http://highered.mcgraw-hill.com/sites/0072437316/student_view0/chapter11/animations.html#

http://www.cellsalive.com/mitosis.htm

5.1 Mitosis

•Cytokinesis•Controlled mitosis

•Uncontrolled mitosis

Centrioles

Chromatin

Interphase

Nuclear envelope

Cytokinesis

Nuclear envelope reforming

Telophase

Anaphase

Individual chromosomes

Metaphase

Centriole

Spindle

CentrioleChromosomes

(paired chromatids)

Prophase

Centromere

Spindle forming

Go to Section:

Do you still remember this phase

Centrioles

Chromatin

Interphase

Nuclear envelope

Cytokinesis

Telophase

Anaphase

Metaphase

Centriole

Spindle

(paired chromatids)

Prophase

Centromere

Spindle forming

Go to Section:

Centrioles

Chromatin

Interphase

Nuclear envelope

Cytokinesis

Telophase

Anaphase

Metaphase

Centriole

Spindle

(paired chromatids)

Prophase

Centromere

Spindle forming

Go to Section:

Centrioles

Chromatin

Interphase

Nuclear envelope

Cytokinesis

Telophase

Anaphase

Metaphase

Centriole

Spindle

(paired chromatids)

Prophase

Centromere

Spindle forming

Go to Section:

Centrioles

Chromatin

Interphase

Nuclear envelope

Cytokinesis

Telophase

Anaphase

Metaphase

Centriole

Spindle

(paired chromatids)

Prophase

Centromere

Spindle forming

Go to Section:

Share your idea!!

You now that cell will divide into two daughter cell but how the cell will divide after the telophase????

How cell divide?

• 1.

• 2.

• 3.

• 4.

ACTIVITY: JIGSAW1. Please sit in group of five or four

2. Discuss in group the subtopic given in task sheet

3. after finish discussion in group (10 min), you need to distribute into another group and explain about the subtopic you get until your friends understand(5 min)

Cytokinesis:

• Cytoplasm of the cell and its organelles separate into 2 new daughter cells

• In animals, a groove called the cleavage furrow forms pinching the parent cell in two

• In plants, a cell plate forms down the middle of the cell where the new cell wall will be

What can limit cell growth?

• Think about what can limit your growth

• Hmmm….think about an ant, a tennis ball, and a basketball

• Space– Surface/volume ratio

• What could happen if cells continue to grow without any limits?

Cancer

• Cancer is one of the most common diseases in the developed world:

• 1 in 4 deaths are due to cancer• 1 in 17 deaths are due to lung cancer• Lung cancer is the most common cancer in men• Breast cancer is the most common cancer in

women• There are over 100 different forms of cancer

Cancer

• The division of normal cells is precisely controlled. New cells are only formed for growth or to replace dead ones.

• Cancerous cells divide repeatedly out of control even though they are not needed, they crowd out other normal cells and function abnormally. They can also destroy the correct functioning of major organs.

DNA mutations disrupt the cell cycle.

Mutations may be caused by:

1. radiation 2. smoking 3. Pollutants 4. chemicals 5. viruses

What can cause cancer?

1. a chemical in the coal dust caused damage to genes that regulate the cell cycle.

• Pott was probably the first person to associate a specific type of cancer (scrotal cancer) with a specific occupation (chimney sweeping).

• Pott believed the problem was the coal soot that caught in the skin folds of the scrotum. In 1918, coal tar was shown to cause skin cancer in rabbits, and in 1924 the causative agent was identified as polycyclic aromatic hydrocarbons, especially benzo (a) pyrene.

2.X-rays damages genes that regulate the cell cycle.

• Ionizing radiation is a well-known human carcinogen. The first reports of association between X-rays and cancer appear in the literature in the early 1900s.

• cancer developed among painters of luminescent dials in watch factories in the 1930s

• and radiation from nuclear tests and cancer (for example, children in the Marshall Islands exposed to radioactive iodine released from a nuclear test displayed a significant increase in thyroid cancer).

3.exposure to UV light damages genes that regulate the cell cycle.

• The relationship between sun exposure and skin cancer has been clarified greatly across the past century.

• In the late 1800s, observers noticed that sailors exposed to the sun developed a variety of abnormal lesions called "sailor's skin," and in the early 1900s, an increased risk of skin cancer was observed among farmers.

• By 1928, researchers had demonstrated the carcinogenic effect of UV radiation on the skin of laboratory animals. Today, scientists recognize excessive exposure to UV radiation (whether from the sun or other sources) as a key risk factor for skin cancer.

While normal cells will stop dividing if there is a mutation in the DNA, cancer cells will continue to divide with mutation.

TumoursTumours

Abnormalities can sometimes occur in cells which reproduce at a rapid rate, this in turn may lead to the formation of tumours.

Tumours of any type should be considered serious.

Although benign tumours do not usually cause a threat to a persons life, they can cause great inconvenience if not treated.

Applying your idea• Individually, answer all this question.

• Submit the answer at the end of the class.

Cytokinesis? (10 minutes)

• How cytokinesis occurs in animal cells?• How cytokinesis occurs in plant cells?• How many new cells formed? The new cells called as?• Compare size of new cells to each other?• Compare size of new cells & parent cell?• Daughter cells & parent cell genetically identical or

different? Give reason to your answer.

Controlled and uncontrolled mitosis (15 minutes)

• what is defined as controlled mitosis?

• Why the rate and timing of cell division important?

a._______________________b_______________________c_______________________• What cell continue divide throughout our life? • What cell do not divide at once they mature

• what is defined as uncontrolled mitosis?

• What factor can cause uncontrolled mitosis?

• What is tumour?

• What is benign tumour? Do benign tumour is dangerous?

• What is malignant tumour?

• Can cancer cell spreads through our body? If yes, how the cancer cell spreads?

Aplication of mitosis

The story story…

• You are a scientist which explore the forest to find out a rare plant species. One day, you find the plant after few month you are doing research in the forest. However, the people there not allow you to take out the plant out from the place but they allow you to take the piece of the meristem tissue of the plant. What can you do with the tissue so that you are able to replant and commercialized the plant.

Do you have watching this movie???

Or this???

• What do you know about

Cloning?

Chapter 5: Cell division

Mitosis- APPLICATION OF MITOSIS

Cloning

• Asexual organism reproduce clones.

• Clone has same genetic content and chromosomal number

• Cloning is the process to produce genetically identical organism

Cloning in plant

• Technique of cloning plant known as tissue culture

Tissue culture laboratory

How to do tissue culture?

Animal cloning

• Definition: The process of making identical genomic copies of an original animal.

Brief History of Cloning• 1952: Briggs and King clone tadpoles.

• 1953: Watson and Crick find the structure of DNA.

• 1962: John Gurdon clones frogs from differentiated cells.

• 1963: J.B.S. Haldane coins the term ‘clone’.

Brief History of Cloning• 1977: Karl Illmensee creates mice with

only one parent,

• 1984: Twinning- create genetic copies from embryonic cells.

• 1996: First animal cloned from adult cells is born.

The Cloning Process• 1978: Splitting embryos

• 1986: Embryo Cloning

• 1994: Embryonic cell line cloning

• 1996: Adult or Somatic cell cloning

Step of cloning-Stage 1

Cell collected from a sheep’s udder.

Stage 2

Nucleus is removed from unfertilized egg of second sheep.

Stage 3

Udder cell is inserted into egg with no nucleus.

Stage 4

Insertion is successful.

Stage 5

Electrical charge is supplied.

Stage 6

Cells begin to divide.

Stages 7 & 8

Dolly The SheepDolly The Sheep

Hello DollyDolly was the first mammal cloned from an adult cell.

She was born in 1996 and died in 2003.

She was 6 when she died, about half the usual age for a sheep

I am copy cat

From National Geographic

• Scientists in Texas have successfully cloned a cat, opening the way to replicating pets and other valued animals once the technique is perfected.

The kitten, called CC (the old typist's abbreviation for carbon copy) and now almost two months old, appears healthy and energetic, although she is completely unlike her tabby surrogate mother, Mark Westhusin and colleagues at Texas A&M University, College Station, announce in the February 21 issue of Nature.

Chapter 5 Cell Division 2003v

Documents

Cell Division / Cell Reproduction Chromosome (Package for DNA during Cell Division)

08 06 Xian Saito Talk 2003v

Cell division, cell growth, cell Cycle

Reproduction and Cell Division (8) Reproduction and Cell Division (5.8) Reproduction and Cell Division (5.8) The Cell Cycle and Mitosis (5.5) The Cell

Cell Division. Cell division consists of two phases: ● nuclear division ● cytokinesis = division of the cytoplasm

Www.soran.edu.iq M. Saadatian Cell division 1. Cell division Mitosis

Lisha Kill 2003v

Chapter 8: Cell Growth and Division. Cell Growth Describe cell growth Define cell division Relate cell growth to cell division

Cell division Mitosis and the cell cycle Key Knowledge Cell replication Mitosis and cytokinesis Cell growth Cell division

Cell cycle & cell division

Cell Cycle and Cell Division · Cell Cycle and Cell Division •เป็นที่อยู่ของ หน่วยพันธุกรรม( gene ) ซึ่งท าหน้าที่ควบคุมและถ่ายทอดข้อมูล

Cell Cycle & Division Biology I. Cell Division Cell Division: All cells are derived from preexisting cells (Cell Theory) Cell division is the process

Cell Cycle Cell Division

Chapter 3: Cell Division 3.1 Cell division occurs in all organisms 3.2 Cell division is part of the cell cycle 4.3 Meiosis is a special form of cell division

Reproductive Biology Cell Division –Somatic cell division (Mitosis) –Reproductive cell division (Meiosis) Flowering and Anthesis –Megagametogenesis (EMC

Cell Division Mitosis & Meiosis. Mitosis cell division somatic cell (body cell) The form of cell division by which a eukaryotic somatic cell (body cell)

Cell Division! 3.1: Cell division occurs in all organisms

Chapter 10: Mitosis Cell Growth and Division. Cell Division Cell Division – cell divides into two new IDENTICAL “daughter cells” Mitosis – division of

Cell Division: The Cell Cycle

Cell Division Meiosis Cell Division Meiosis Abnormal Meiosis