asexual reproduction adjh- h. aucoin. how do cells make new cells what happens when you cut a worm...

Asexual reproductionAsexual reproduction

ADJH- H. AucoinADJH- H. Aucoin

How do cells make new cellsHow do cells make new cells

What happens when you cut a worm in half? What happens when you cut a worm in half? Why do you think you can grow new skin Why do you think you can grow new skin over a cut on your hand but you can’t grow over a cut on your hand but you can’t grow new fingers?new fingers?


What is reproduction?What is reproduction?

Reproduction is the process by which Reproduction is the process by which organisms produce more of their own kind.organisms produce more of their own kind.

Think about it – Without reproduction, all Think about it – Without reproduction, all

life on earth would no longer exist. life on earth would no longer exist.


The cell cycle in your bodyThe cell cycle in your body Cells don’t live forever, they eventually die.Cells don’t live forever, they eventually die. Some cells life spans:Some cells life spans:

Brain cells: 30 – 50 yearsBrain cells: 30 – 50 yearsRed blood cells: 120 daysRed blood cells: 120 daysStomach lining cells: 2 daysStomach lining cells: 2 daysSkin cells: 20 daysSkin cells: 20 days

You need mitosis and cell division to replace these You need mitosis and cell division to replace these cells.cells.

In your body about 3 billion cells die every minutes.In your body about 3 billion cells die every minutes.ADJH- H. AucoinADJH- H. Aucoin

Skin and bones can be healed because Skin and bones can be healed because they undergo mitosis and can replace they undergo mitosis and can replace injured cells.injured cells.

Research says that we age because as Research says that we age because as some cells die, they are not replaced or some cells die, they are not replaced or they are replaced more slowly , it is not they are replaced more slowly , it is not known for sure.known for sure.


CancerCancer

Cancer occurs when cells begin to divide Cancer occurs when cells begin to divide uncontrollably.uncontrollably.

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

Tumors/lumps are formed from the cells Tumors/lumps are formed from the cells that pile up on each other.that pile up on each other.


When you cut yourself, cells in that area over time multiply, fix the When you cut yourself, cells in that area over time multiply, fix the cut, and then slow their growth. Cancer stems from mutated cells cut, and then slow their growth. Cancer stems from mutated cells who do not stop growing. who do not stop growing.

Cancerous cells start with a Cancerous cells start with a mutation in the cell's in the cell's DNA. . Mutations in a cells DNA can be caused by either genetic inheritance or the in a cells DNA can be caused by either genetic inheritance or the environment (ie. smoking, sunlight exposure, radiation, etc)environment (ie. smoking, sunlight exposure, radiation, etc)(http://nanopedia.case.edu)(http://nanopedia.case.edu)

Cancer becomes malignant and fatal once its growth becomes Cancer becomes malignant and fatal once its growth becomes intrusive on nearby tissues and organs, sometimes causing pain.intrusive on nearby tissues and organs, sometimes causing pain.[3] Also, further problems arise when metastasis occurs and Also, further problems arise when metastasis occurs and cancer cells break away from the main growth and circulate in cancer cells break away from the main growth and circulate in lymphatic and/or blood vessels. Once these renegade cells lymphatic and/or blood vessels. Once these renegade cells relocate, they can cause additional tumors.relocate, they can cause additional tumors.[7]ADJH- H. AucoinADJH- H. Aucoin

http://nanopedia.case.edu/NWPage.php?page=news2.13

http://nanopedia.case.edu/NWPage.php?page=dna.structure

http://nanopedia.case.edu/NWPage.php?page=news2.13

http://nanopedia.case.edu/NWPage.php?page=news2.biblio

http://nanopedia.case.edu/NWPage.php?page=news2.biblio

Once the mutation occurs, the cell begins Once the mutation occurs, the cell begins to multiply at an increased rate, passing its to multiply at an increased rate, passing its mutated DNA on to further generations. mutated DNA on to further generations. They continue to grow and lead to an They continue to grow and lead to an unwanted, benign cluster. unwanted, benign cluster.

Cancer becomes malignant and fatal once Cancer becomes malignant and fatal once its growth becomes intrusive on nearby its growth becomes intrusive on nearby tissues and organs. tissues and organs.


What is Asexual Reproduction?What is Asexual Reproduction?

Only one parent is involved.Only one parent is involved. Offspring are genetically identical to their Offspring are genetically identical to their

parents.parents. All cells that come from a single cell are All cells that come from a single cell are

genetically identical to it and to each other; genetically identical to it and to each other; they are all clones.they are all clones.


Types of Asexual ReproductionTypes of Asexual Reproduction

1.1. MitosisMitosis - is the exact - is the exact duplication of the duplication of the nucleus of a cell so as nucleus of a cell so as to form two identical to form two identical nuclei during cell nuclei during cell division.division.



22. . Binary FissionBinary Fission - occurs - occurs in one-celled organisms in one-celled organisms such as the ameba and such as the ameba and paramecium. The nucleus paramecium. The nucleus divides by mitosis and the divides by mitosis and the cytoplasm divides, cytoplasm divides, forming 2 new daughter forming 2 new daughter cells of equal size.cells of equal size.



3. 3. BuddingBudding - Occurs in Hydra and yeast. The division of - Occurs in Hydra and yeast. The division of cytoplasm is unequal so one of the daughter cells is cytoplasm is unequal so one of the daughter cells is larger than the other. The daughter cells can separate larger than the other. The daughter cells can separate or remain attached. A copy of the nucleus is made, or remain attached. A copy of the nucleus is made, then a tiny bud begins to form on the cell wall. This then a tiny bud begins to form on the cell wall. This bud, containing the new nucleus continues to grow and bud, containing the new nucleus continues to grow and eventually breaks away. eventually breaks away.


Types of Asexual ReproductionTypes of Asexual Reproduction4. 4. SporulationSporulation - occurs in - occurs in

molds, mosses, etcmolds, mosses, etc SporesSpores are produced in are produced in

large numbers by mitosis.large numbers by mitosis.

Spores are surrounded by a Spores are surrounded by a tough coat to help them survive tough coat to help them survive harsh environmental conditions. harsh environmental conditions. When mature, and the When mature, and the sporangiumsporangium explode, and the explode, and the spores can now float on air spores can now float on air currents and begin the whole currents and begin the whole process over again.process over again.



5.5.RegenerationRegeneration - - Refers to the Refers to the replacement or replacement or regrowth of lost regrowth of lost or damaged or damaged body partsbody parts



6. Fragmentation – a small piece or fragment, breaks away from the main mass and grows into a new individual.


7.7.Vegetative PropagationVegetative Propagation Occurs only in plants. Occurs only in plants.

Meristemic cells (non Meristemic cells (non specialized cells) help specialized cells) help new plants to develop new plants to develop from the roots, stems, or from the roots, stems, or leaves of the parent plant.leaves of the parent plant.

Types of Asexual Reproduction


RunnersRunners- - Runners are Runners are specialized stems called stolons. specialized stems called stolons. These stems grow horizontally These stems grow horizontally outward and downward from outward and downward from plants and produce baby plants at plants and produce baby plants at their tips. their tips. . (ex. strawberries). (ex. strawberries)

Grafting- Grafting- horticultural horticultural techniques used to join techniques used to join parts from two or more parts from two or more plants so that they appear plants so that they appear to grow as a single plant. to grow as a single plant. ((For instance, a Macintosh seed will grow For instance, a Macintosh seed will grow into an apple tree, but not into a Macintosh into an apple tree, but not into a Macintosh apple tree, which can only be achieved apple tree, which can only be achieved through grafting.)through grafting.)

Types of Asexual Reproduction


Tissue Culture

Asexual reproduction– Brain Pop ADJH- H. AucoinADJH- H. Aucoin

asexual reproduction adjh- h. aucoin. how do cells make new cells what happens when you cut a worm...

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