A)
(i) The two cell poles of S. pombe have different characteristics. Morphologically they can be distinguished from each other by their distance from the division scar.
(ii) The growth characteristics of the two poles also differ. The old pole is further away from the division scar, which is shown as distance “a”. The new pole is closer to the division scar. The distance is “b”. Prior to G2 cells, only grow from the old pole and “a” increases.
(iii) In G2, after cells reach a critical size, NETO (new-end-take-off) occurs and cells begin to grow at both cell poles (“a” and “b” increase).
B) Growth rate changes during cell cycle in S. pombe. See text for details. The graph represents the growth pattern of a single cell. Cell length and rate of protein synthesis are shown as arbitrary units. Cell cycle length is shown on the x-axis with 0 representing the birth of the cell and “1” describing the end of the cell cycle. Adapted from [12].

A) Cell volume (dashed lines) and cell mass (solid line) of single cells were measured by light and interference microscopy, respectively. Cell density was calculated based on the measured volume and mass (Reprinted with permission from [21]).
B) Growth potential varies during the yeast cell cycle. Various cell cycle mutants were arrested at the indicated cell cycle stage and their volume was measured using a coulter counter 10 hours after shift to the restrictive temperature (Reprinted with permission from [23]).
C) Changes in actin organization during the cell cycle of S. cerevisiae. Black wavy lines represent actin cables and red arrows indicate the locations of cell growth (vesicle deposition). Stages of the cell cycle are indicated under the Roman numeral. See text for detailed explanation.