Most of the dry mass of a plant is the result of uptake of _____.

A. Water and minerals through root hairs

B. Carbon dioxide through stoma

C. Carbon dioxide and oxygen through stomata in leaves

D. Water and minerals through mycorrhizae

Compared to C₃ plants, C₄ plants _____.

A. Can continue to fix CO₂ even at lower CO₂ concentrations and higher oxygen concentrations

B. Make a four-carbon compound, oxaloacetate, which is then delivered to the citric acid cycle in mitochondria

C. Do not use rubisco for carbon fixation

D. Have higher rates of photorespiration

A botanist discovers a new species of land plant with a dominant sporophyte, chlorophylls a and b, and cell walls made of cellulose. In assigning this plant to a phylum, which of the following, if present, would be LEAST useful?

A. Seeds

B. Flowers

C. Spores

D. Endosperm