General Biology II · Module 10 · Plant reproduction and responses

Plant Reproduction and Responses Lab

Grow seedlings toward light and against gravity, time flowering with night breaks, ripen fruit with ethylene, train on predictions and chromosome counts with animated worked solutions, match the key terms, and read real experiments. Nothing here is graded.

Part 1: Plant Response Bench

Pick a chamber, change the conditions and watch the plant respond. Time runs much faster than real life.
Auxin Phytochrome Pr Phytochrome Pfr FT (florigen) Ethylene Statoliths
Live readouts
MeasureValue

Teaching model with simplified, rounded rules. Seedling: blue (and white) light from one side shifts auxin to the shaded side; red and far-red light barely drive phototropism; gravity shifts auxin to the lower side; 1 second is about 2 simulated hours. Phytochrome: about 85% Pfr in red light, 60% in white, 3% in far-red, slow reversion to Pr in the dark. Photoperiod: the short-day plant flowers after 5 cycles with an unbroken dark period of at least 12 h; the long-day plant after 5 cycles with less than 10 h; the last flash of a night break decides whether the night is broken. Ripening: climacteric fruit respond to about 1 ppm ethylene and make their own once ripening starts (positive feedback); rate roughly 2.5 times faster per 10 °C; bananas are injured below about 13 °C.