Cells Provide Strength

broken and splintering pieces of wood in various shades of brown

Biological Strategy

AskNature Team

Image: T. Selin Erkan / Unsplash / Some rights reserved

Manage Tension

When a living system is under tension, it means there is a force pulling on it, like a person pulling on a rope tied to a horse. When applied to a living system, unless the system is completely rigid, the result is that it gets stretched. If stretching exceeds the strength of the living system’s material, it can damage it. Living systems manage tension using materials that are flexible and stretchable enough to survive most tension that occurs in their environment. The ocean’s intertidal zone offers a good example. The waves and incoming and outgoing tides put tension on soft-bodied organisms. Mussels resist tension with flexible threads that hold them onto rocks; in contrast, large algae have stretchy fronds.

Search this Function

Flowering Plants

Clade Angiosperms (“receptacle seed”): Dandelions, oaks, grasses, cacti, apples

With 416 families containing some 300,000 known species, angiosperms are the most diverse group of plants, and they can be found around the globe in a wide variety of habitats. They are characterized by seeds that grow enclosed in ovaries, which are enclosed in flowers. The floral organs then develop into fruits of myriad kinds and dimensions, from simple seed casings on maples to elaborate fleshy growths like papayas. The oldest flower known from fossils, Montsechia vidalii, appeared during the Jurassic Period 130 million years ago. They are the primary food source for herbivorous animals, which in turn makes them the indirect food source for carnivores as well.

Search this Living System

Cells and cellulose microfibers of woody plants provide tensile strength due to their position of long axes parallel to the direction of the tensile force.

“Because plant structures are formed by the assembly of cellular units, tensile materials made from do not contain the long, continuous fibers characteristic of such tensile materials as tendon. Rather, tensile plant materials consist of linear aggregates of cellular units which form fibrous structures. The cells found in these fibrous structures are normally elongated with their long axes parallel to the direction of the tensile force, and the cellulose microfibrils within the walls of these fibre cells have a high degree of preferred orientation parallel or nearly parallel to the long axis of the cell.” (Wainwright 1976)

Last Updated August 18, 2016

References

Book

Mechanical Design in Organisms

01/07/1982 | Stephen A. Wainwright

embedly preview

AskNature