Fragmentation

The idea

In fragmentation, a multicellular organism with a simple body organisation breaks up into smaller pieces on maturing, and each fragment grows into a new individual.

Green threads

Spirogyra is a green thread-like organism made of many cells joined end to end.

What can happen when it matures?

• It breaks into smaller pieces, each a new Spirogyra
• It lays eggs
• It makes a flower

Spirogyra breaks up

Press Next step.

Break up, grow up

Fragmentation works in a simple multicellular body. When the thread matures, it breaks into pieces, and the pieces grow into new individuals.

In fragmentation, a multicellular organism with a simple body organisation breaks up into smaller pieces on maturing, and each fragment grows into a new individual.

Notes

In fragmentation, a simple multicellular organism breaks into pieces on maturing, and each fragment grows into a new individual.

Check yourself

Which organism reproduces by breaking into smaller pieces on maturing?

What does each fragment of Spirogyra do?

Fragmentation is used by multicellular organisms that have …

• Spirogyra — correct. Yes!
• Plasmodium. Plasmodium divides into many daughter cells by multiple fission.
• Amoeba. Amoeba is unicellular and divides by fission.
• Dies out. Each fragment grows into a new individual.
• Grows into a new individual — correct. Yes!
• Joins the other fragments again. The fragments grow into separate new individuals.
• tissues and organs at definite positions. The book says that for such carefully organised bodies, cell-by-cell division would be impractical.
• only one cell. An organism with one cell is unicellular and reproduces by fission.
• a relatively simple body organisation — correct. Yes!