TOPIC: Reproduction & Development AIM: How do living things reproduce asexually?

TOPIC: Reproduction & DevelopmentAIM: How do living things reproduce asexually?

All types of asexual reproduction involve

MITOSIS

1.What type of organisms do these cartoon creatures represent?

2.Why does the younger organism look like both adult organisms?

1.Binary Fission:

•Unicellular organisms

•Mitosis 2 new identical offspring

•EQUAL DIVISION of cytoplasm

•Ameba, paramecium, bacteria…

2.Budding:•Mitosis UNEQUAL division of cytoplasm

•New organism (bud) smaller than parent but has same # of chromosomes

•Ex: hydra, yeast

3.Sporualtion•Formation of spores• Cells that divide by mitosis into new organism

•Ex: Bread mold, mushrooms…

4. Regeneration:a. Ability to regrow lost body parts

b. New organism forms from part of the parent

•Ex: starfish, lobsters, lizards, planaria

Regeneration of the freshwater planaria (flatworm) This flatworm can be cut into as many as thirty-two pieces and it

can rebuild itself into thirty-two complete flatworms.

Salamanders: Salamanders can regenerate legs. When a salamander is in the larval stage, it can regenerate a limb in thirty to forty days! Adult salamanders can also regenerate limbs, but it takes much longer and the leg is not as large as the original one.

Lizards: Lizards have the ability to replace lost limbs or a lost tail. This is important because when a predator such as a hawk captures the tail, the lizard can escape. The new tail lacks the backbone of the original tail.

Frogs: A younger frog can regenerate limbs to a better extent than an adult frog. For example, the tadpole can regenerate its hind limbs.

Earthworm: When the worm is cut into two pieces, the head grows a new tail. Interestingly, the tail grows another tail if the portion cut off is larger than 15-20 segments. With two tails, this portion dies.

Crayfish: Cray fish can regrow claws, pinchers, or legs. It is easy to recognize the regenerated part because it is smaller than the other parts. Just like the lizard, it can break off a claw or leg so that it can escape when captured by a predator.

5. Vegetative Propagation•Asexual Rep in plants•NO SEEDS•Part of plant grows into new plant by mitosis

•Types:a. Runners =Stems that grow

over surface of soil –Ex: Strawberries

b. Bulbs = underground stems for food storage –Ex: tulips, onions

c. Tubers = enlarged part of underground stem that store food –Ex: Potatoes

6. ArtificialVegetativePropagatio

n

•Occurs as a result of human activities

•Types:

a. Cuttings = any part from roots, stems, or leaves that can develop into new plants by MITOSIS

b. Grafting = cutting from one plant attached to stem of another plant–Ex: Seedless Oranges

Graft at 2 months

Graft at 4 months

Graft at one year

Graft at three years