Regeneration n Is n Is the ability to regrow a tissue, an organ or a part of the body n Humans n Humans can regenerate: blood, bone, skin

Animals that Regenerate n What animals can regenerate? n Many animals can grow new parts of their bodies to replace those that have been damaged n LIZARDS--> tail

Animals that Regenerate n Planarians-->if cut into pieces, each piece will grow into a new worm (p.186) n Sea Cucumbers--> body is three feet long. If cut, can grow new sea cucumber n Sharks-->continually replace lost teeth n Spiders--> regrow missing legs or parts of legs n Sponges--> can be divided, and will regrow to be exactly as before.

Animals that Regenerate n Starfish--> that lose arms can grow new ones n Sometimes an entire animal can regrow from a lost arm

Fragmentation n A form of asexual reproduction where a new organism is formed from a part that breaks off from the parent n ie. Sponge, planarian

Cell Specialization n The nucleus of every cell contains a complete code for your characteristics. n (Every cell contains identical DNA) n Why can skin cells regenerate when nerve cells can’t? n Because each cell uses only a specific part of their DNA. n Ie. The muscle producing part of DNA is turned off in nerve cells

Cell Specialization cont’d n Animals with little cell specialization are capable of regeneration n The cells of these organisms are very similar n Complex animals (like dogs, elephants etc.) have more cell specialization (where specific parts of the DNA are turned off)

Producing Plants without Seeds n What happens to a potato when it has been left for a while? n It grows eyes (tiny buds) n see p.190

Potatoes n So, when farmers grow potato crops, they make sure a section of the potato containing an eye is planted

n Using a potato eye to grow a new potato is a type of asexual reproduction n What are some other examples of growing a new plant from another plant? n ie. Spider plant

Fact n When a new plant that has been grown from an already existing plant, is the new plant is genetically identical to the parent? n Yes!

Dolly

Dolly