Plants grow in many different shapes and sizes. Much of their shape depends on an internal structure that is composed of carbon-containing molecules such as cellulose and lignin. Plants that have a strong internal structure can grow larger than other plants because their structure can support their size.

Plants obtain the majority of the carbon necessary for building these structural molecules from —

A) air

B) microorganisms

C) soil

D) water

A. Air

Explanation:

Lignin which has a glucos link is a unique hydrocarbon comprising 8-20% of the cell wall of plants. It is a complex, dense, amorphous, secondary cell wall polymer found in the trachea elements and sclerenchyma of terrestrial plants.

Since plant absorbs carbon dioxide from air to form glucose and hence, starch; That is the source of carbon to build other macromolecules.

Water which it absorbs from soil is not of carbon content neither do plant take in microorganisms.

the role of the microscope world in creating new materials .