g7 ch4.2 - asexual reproduction

Asexual Reproduction

Chapter 4 Lesson 2

p.128-137

Asexual Reproduction• A one-parent organism produces offspring

without meiosis and fertilization

• Offspring inherit the parent DNA

• Genetically identical

Budding

Animal Regeneration

Cloning

Vegetative Reproduction

Mitotic Division

Fission

AsexualReproduction

Fission• Prokaryotes divide rapidly through fission

– Pro = No (no nucleus)

• Steps1. The DNA molecule is copied

2. Each copy attaches to the cell membrane

3. Cell grows and splits

4. Finally, two new cells with one copy of the DNA*Original cell no longer exists

Fission

Mitotic Division• Unicellular Eukaryotes

– Eu = Yes (Yes, it has a nucleus)

• Unicellular organism divides by mitosis and cytokinesis.

Budding• A new organism grows by mitosis on the

body of the parent

• Genetically Identical

• When bud is large enough it can break from the parent

Animal Regeneration

Animal Regeneration• Offspring grow from a piece of the parent

• When the parent is cut or divided, the pieces has the potential to grow into a new organism

Regeneration• “Regeneration” also means the ability to

grow back parts of the body

• This is not asexual reproduction because it goes not produce a new organism

Vegetative Reproduction

• Offspring grows from a part of the parent plant

Cloning• Asexual reproduction done in a

laboratory to produce identical individuals from a cell or a cluster of cells taken from a multicellular organism

Cloning - Plants• Grown from meristems in culture

• “Meristem” – stem cells

Cloning - Animals• All the clone’s chromosomes come from

one parent

• The first mammal cloned was a sheep named Dolly

• Could save endangered species

• Ethical issues

Cloning - Animals