Each multiple choice question is worth 3 points. A band of microtubules in the cortex of the cell appears to mark the future plane of cell division. Microtubules run perpendicular to the direction of cellulose microfibrils, thereby providing additional mechanical support to the cell. Cell differentiation or maturation usually follows cell elongation. Lateral roots and branches each originate from the same type of meristem tissue at the surface of the plant.
Epidermal tissue contains a waxy water-impermeable coat called the cuticle.
Rubisco, the enzyme that catalyzes the initial fixation of CO2, is an extremely abundant protein in plants. Not all plants do CO2 fixation during the day. The enzymes of the Calvin cycle are located in the stroma of the chloroplast. The final electron acceptor during fermentation is an organic molecule. A contractile ring of actin filaments helps form the cleavage furrow of animal cells.