AP BIOLOGY

Detailed explanation-1: -From examination of two images taken under a microscope, approximately 450 cells were tallied. Approximately 60% of the cells were in interphase. The next most common stage observed was prophase, and 35% of cells were in this phase.

Detailed explanation-2: -Interphase. The cell is engaged in metabolic activity and performing its duty as part of a tissue. The DNA duplicates during interphase to prepare for mitosis (the next four phases that lead up to and include nuclear division).

Detailed explanation-3: -Metaphase. They are shortest and thickest in this stage and in their condensed form.

Detailed explanation-4: -Although the cells of an onion root tip are actively growing, the longest and most common phase for this tissue is still Interphase. Cells spend the longest amount of time in interphase to ensure that cell size has increased properly and DNA has been replicated accurately prior to mitosis and cytokinesis.