Asexual Reproduction

Advantages and Disadvantages

Binary Fission

Bacteria reproduce by a process called binary fission

Binary fission: a copy of their single chromosome is produced and then the cell divides in half so that one half gets one chromosome and the other half gets the other chromosome

Because the chromosome was duplicated, each new cell receives a complete set of hereditary information

Asexual Reproduction Binary fission is an example of asexual

reproduction in single celled organisms Multi-cellular organisms that

reproduction asexually is more complex and occurs in the nucleus through mitosis.

Only types of asexual reproduction are: Budding Fragmentation Gemmules (Internal Buds) Regeneration

Budding

Offspring grows out of the body of the parent

Hydras exhibit this type of reproduction Jellyfish also reproduce through budding

Sponges

Sponges reproduce asexually through gemmules (internal buds)

A parent releases a specialized mass of cells that can develop into an offspring

Fragmentation

In this form of asexual reproduction, the body of the parent breaks into distinct pieces, each of which can produce an offspring.

Molds, yeast and some mushrooms reproduce in this way.

Regeneration

If a piece of a parent is detached, it can grow and develop into a completely new individual.

Flatworms use this type of asexual reproduction.

Mitosis

In a complex cell going through asexual reproduction, the nucleus divides during a process called mitosis.

Mitosis ensures that each new cell received the same number and kinds of chromosomes that were present in the parent cell.

In both binary fission/mitosis, these processes produce two offspring with hereditary information that is identical to the parent cell.

Mitosis

Advantages and Disadvantages of Asexual Reproduction

Advantage: an organism does not have to wait for a partner to be able to produce offspring.

Disadvantage: the offspring are exactly like the parents (no variation in DNA).

Asexual reproduction does not allow organisms to have variation from generation to generation. (could cause an organism to die out if changes occur in ecosystem)