Non-bioriented bivalents do not prevent APC activation in smaller oocytes. (A) Representative time-lapse images of B₀ and B₃ oocytes expressing H2B-mCherry (green) and CenpC-GFP (red) with time relative to anaphase. Arrowheads indicate non-bioriented bivalents in both types of oocyte. Bar, 10 µm. (B) Cartoon depicting measurements of stretch, displacement and θ on a bivalent with sister kinetochore pairs (red). (C) Number of bivalents per oocyte classed as non-bioriented (>3 SDs from the control mean in any of the parameters of stretch, displacement, or θ) at times relative to anaphase; n.s. not significant. (D) 3D plot of bivalents in B₃ oocytes 5 min before anaphase, indicating the spread of stretch, displacement, and θ. Colors indicate the number of SDs a bivalent is, according to its worst-performing measure, from mean values defined by metaphase oocytes treated without nocodazole (green <1, yellow ≤2, orange ≤3, and red >3). (E and F) Proportion of bivalents falling within the stated number of SDs at anaphase −5 min for B₀ (E) and B₃ (F) oocytes. Error bars indicate SD.