REPRODUCTIONSexual and Asexual

ReproductionReproduction – the process of living things producing the

same type of living thing.Examples – horses produce horses, humans produce

humans, and tomato plants produce tomatoes.* Like produces like.There are two types of reproduction: asexual and sexual

Asexual Reproduction

Living things that reproduce from only one parent.

Examples: Regeneration, budding, and cellular division.

Advantages of Asexual Reproduction:• animals that live in one place & unable to look for mates reproduce asexually.

• numerous offspring can be produced without a great amount of energy or time.

• One single organism can start new colonies in new locations.

• Mating partners are not needed to be found.• More reliable (less to go wrong in cell division)

Disadvantages of Asexual Reproduction:• Species may not be able to adapt to a changing

environment

Regeneration

Regeneration(before)

Regeneration(after)

Crown of Thorns Story

Regeneration(ex. starfish)

Can humans regenerate body parts by asexual reproduction?

Regeneration(ex. Planaria)

Budding(ex: Hydra)

Cellular Division(also called Binary Fission)• Protozoa

Binary Fission(ex. paramecium)

Binary Fission (ex. bacteria)

Asexual Reproduction in Plants

• Propagation-transplanting parts of a plant to a new growing area (ex. Rhizomes, runners, bulb formation, rooting from stems)

• Budding-tiny bud growing off parent plant (ex. Potato “eyes”, branches budding)

• Spores-reproductive cells that produce a new organism (ex. Ferns, mushrooms, molds)

Propagation

Plant Budding

Spores

Sexual Reproduction

Sexual reproduction

usually requires two

parents (partners).

Examples: frogs,

deer, bats, humans,

and flowers.

Surinam Toad• http://www.youtube.com/watch?v=mZ7b4spjXhw

Advantages of Sexual Reproduction:• The offspring will be different than its parents. This allows

the species to adapt to its surroundings.

Galapagos Finches• http://www.youtube.com/watch?v=l25MBq8T77w

Disadvantages of Sexual Reproduction:

• Often slower than asexual reproduction, and less reliable (more mutations, problems)

• Much energy is used in mating processes• http://videos.howstuffworks.com/animal-planet/28366-fooled-by-nature-bowerbirds-seduction-video.htm

• Can’t always find suitable mate

TWO TYPES OF REPRODUCTION

• 1. Internal Fertilization

• 2. External Fertilization

Internal Fertilization• Conjugation-

Sexual reproduction

between microscopic

organisms

Asexual budding

External Fertilization• Sex cells are dispersed

out of the body in water• Examples: fish,

salamanders,

jellyfish

Meiosis• Produces sex cells only (sperm or egg cells)• Takes place in the reproductive organs of organisms that

reproduce sexually.