The Cell Cycle In Your BodyThe Cell Cycle In Your Body

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The Cell Cycle In Your BodyThe Cell Cycle In Your Body

The cell cycle is responsible for growth The cell cycle is responsible for growth and development of all your body’s cells.and development of all your body’s cells.

YOU started out as a single cell but YOU started out as a single cell but through the process of MITOSIS you through the process of MITOSIS you became a living system composed of became a living system composed of trillions of cells working together.trillions of cells working together.

Here’s how it works!Here’s how it works!

The Cell Cycle In Your BodyThe Cell Cycle In Your Body AllAll of your body cells are of your body cells are specializedspecialized (each (each

designed for one particular purpose.designed for one particular purpose.

Groups of Groups of specialized cellsspecialized cells form form tissuestissues..

Groups of Groups of specialized tissuesspecialized tissues form form organsorgans..

Groups of Groups of specialized organsspecialized organs form form organ organ systemssystems

The Cell Cycle In Your BodyThe Cell Cycle In Your Body

CELLSCELLSformform

TISSUESTISSUESformform

ORGANSORGANSformform

ORGAN SYSTEMSORGAN SYSTEMS

The Cell Cycle In Your BodyThe Cell Cycle In Your Body

The Cell Cycle In Your BodyThe Cell Cycle In Your Body

The cell cycle ensures that the number of The cell cycle ensures that the number of chromosomes in the nuclei of your cells will chromosomes in the nuclei of your cells will remain constant.remain constant.

All human beings have the same number of All human beings have the same number of chromosomes in each nucleus of every cell.chromosomes in each nucleus of every cell.

How many chromosomes does a human How many chromosomes does a human being have?being have?

The Cell Cycle In Your BodyThe Cell Cycle In Your Body Dogs have 78 chromosomesDogs have 78 chromosomes

Tomato plants have 24 chromosomes.Tomato plants have 24 chromosomes.

Humans have 46 chromosomes - they are Humans have 46 chromosomes - they are arranged in 23 pairs.arranged in 23 pairs.

There are a number of disorders that can affect There are a number of disorders that can affect the number or structure of human chromosomes.the number or structure of human chromosomes.

Chromosomal DisordersChromosomal Disorders

Patau Syndrome (Trisomy 13)occurs Patau Syndrome (Trisomy 13)occurs when an extra chromosome develops when an extra chromosome develops on the 13th pair.on the 13th pair.

Downs Syndrome (Trisomy 21) Downs Syndrome (Trisomy 21) occurs when an extra chromosome occurs when an extra chromosome develops on the 21st pair.develops on the 21st pair.

Patau SyndromePatau Syndrome Newborns with Patau syndrome share Newborns with Patau syndrome share

common physical characteristics:common physical characteristics:

Extra fingers or toes (polydactyly)Extra fingers or toes (polydactyly)

Deformed feet, known as rocker-bottom feetDeformed feet, known as rocker-bottom feet

Neurological problems such as small head Neurological problems such as small head (microcephaly), failure of the brain to divide (microcephaly), failure of the brain to divide into halves during gestation into halves during gestation (holoprosencephaly), severe mental deficiency(holoprosencephaly), severe mental deficiency

Patau SyndromePatau Syndrome

Facial defects such as small eyes Facial defects such as small eyes (microphthalmia), absent or (microphthalmia), absent or malformed nose, cleft lip and/or cleft malformed nose, cleft lip and/or cleft palatepalate

Heart defects (80% of individuals)Heart defects (80% of individuals)

Kidney defectsKidney defects

Chormosomal DisordersChormosomal Disorders

There are a number of, relatively rare There are a number of, relatively rare chromosomal disorders that have been chromosomal disorders that have been identified.identified.

At present there is no cure for any of these At present there is no cure for any of these since every cell in the body is affected the since every cell in the body is affected the same way.same way.

There are many There are many websites websites devoted to devoted to support.support.

Normal Cell ReplacementNormal Cell Replacement

While you grow While you grow mitosis and cell divisionmitosis and cell division add to the add to the total numbertotal number of cells in your of cells in your body.body.

This process continues even after you are This process continues even after you are fully grown simply because cells do not fully grown simply because cells do not live forever - they are continually dying.live forever - they are continually dying.

Normal Cell ReplacementNormal Cell Replacement

Some cells have definite life spans programmed Some cells have definite life spans programmed into their genetic material.into their genetic material.

These cells die when they receive “instructions” These cells die when they receive “instructions” to do so, when they are no longer needed or to do so, when they are no longer needed or when they can no longer function properly.when they can no longer function properly.

Mitosis and cell division are necessary for cells Mitosis and cell division are necessary for cells to be replaced after they die.to be replaced after they die.

Normal Cell ReplacementNormal Cell Replacement

Approximately 3 000 000 000 (3 billion) Approximately 3 000 000 000 (3 billion) cells die each minute!cells die each minute!

Cells can also die when they do not Cells can also die when they do not receive enough food or oxygen or as a receive enough food or oxygen or as a result of damage.result of damage.

Cells must be replaced to maintain a Cells must be replaced to maintain a healthy body.healthy body.

Lifespan of Human Body CellsLifespan of Human Body Cells

RegenerationRegeneration Repair of lost body cells, or making of lost Repair of lost body cells, or making of lost

body parts is called body parts is called regeneration.regeneration.

If you cut your finger or break your leg, cells If you cut your finger or break your leg, cells must be regenerated to repair the cut.must be regenerated to repair the cut.

Some animals can regenerate entire limbs.Some animals can regenerate entire limbs.- the northern plateau lizard can regenerate its tail- the northern plateau lizard can regenerate its tail

- children under the age of 12 may be able to - children under the age of 12 may be able to completely regenerate severed fingertipscompletely regenerate severed fingertips

AgingAging

Research suggests that we age because, as Research suggests that we age because, as cells die they are either not replaced or are cells die they are either not replaced or are replaced more slowly.replaced more slowly.

This process results in changes to the structure This process results in changes to the structure and function of major body systems and function of major body systems - skin wrinkles skin wrinkles - bones lose densitybones lose density- ability to fight disease weakensability to fight disease weakens

AgingAging

Scientists believe that certain changes take Scientists believe that certain changes take place in aging cells that affect their ability to place in aging cells that affect their ability to repair themselves.repair themselves.

CancerCancer

What happens if cells begin to divide What happens if cells begin to divide uncontrollably?uncontrollably?

The result is called cancer.The result is called cancer.

CancerCancer

Cancerous cells interfere with Cancerous cells interfere with surrounding cells abd disrupt surrounding cells abd disrupt their normal functioning.their normal functioning.

They continue to divide and They continue to divide and pile up on one another.pile up on one another.

Excess cells may produce a Excess cells may produce a tumour or lump that stays tumour or lump that stays constant in one area.constant in one area.

CancerCancer In other cases cancerous cells may move to In other cases cancerous cells may move to

other areas of the organism and continue to other areas of the organism and continue to grow and divide uncontrollably.grow and divide uncontrollably.

These cells gobble up oxygen and nutrients These cells gobble up oxygen and nutrients for themselves, crowding out other cells and for themselves, crowding out other cells and robbing them of foodrobbing them of food

Exposure to some substances can increase Exposure to some substances can increase the rate of cancer.the rate of cancer.

CancerCancer

Some carcogenic substances Some carcogenic substances include…include… TobaccoTobacco AsbesosAsbesos Certain chemicalsCertain chemicals Radioactivity and Ultraviolet RadiationRadioactivity and Ultraviolet Radiation

These have all been linked to cancer in humans.These have all been linked to cancer in humans.