Overview
This lecture discusses an experiment to observe the growth pattern of green bean seedlings over 10 days in a controlled environment.
Plant Growth Experiment Setup
- The hypothesis is that seedling height increases with time (number of days).
- Wet cotton is placed in a Petri dish for seed germination.
- Only the best green bean seeds, soaked overnight, are selected for the experiment.
- Three seeds are placed in the dish and kept in a perfectly closed cupboard to ensure darkness.
- Seedling height is measured daily for ten days.
Measuring and Recording Data
- Students measure plant height each day; height cannot be measured directly on weekends, so estimations are used.
- If seedlings grow in a spiral or curved manner, thread is used to follow the stem for accurate measurement.
- All measurements are recorded systematically each day.
Analyzing Growth Patterns
- Recorded heights are plotted on a graph to visualize growth over the 10 days.
- The typical plant growth curve is observed to be upward and curved (non-linear).
- Growth inconsistencies may occur due to various factors such as seed type or environmental conditions.
- Correction for plant height may be needed if the stem is not straight.
Conclusions
- Seedling height generally increases as the number of days increases.
- Recommended to take estimated readings on days when direct measurement isn't possible.
Key Terms & Definitions
- Hypothesis — a testable statement predicting the outcome of an experiment.
- Germination — the process by which a seed develops into a seedling.
- Petri dish — a shallow dish used to grow plants or microorganisms.
- Controlled environment — conditions like light and temperature are kept constant.
Action Items / Next Steps
- Record daily seedling heights for 10 days.
- Plot growth graphs and analyze plant growth patterns.
- Take estimated readings for days without direct measurements.