Biology / Foundations
Biology investigates living systems through evidence.
Biology investigates living systems through evidence. Organisms obtain resources, exchange materials, respond to conditions and reproduce; no single visible movement is enough to identify life.
A useful question links a change to a measurable response. Compare like with like, repeat observations and separate what was observed from the explanation proposed. Models simplify living systems and must be tested against evidence.
Seedlings measure 8, 10 and 12 cm. Find their mean height.
Add the three measured heights: 30 cm; divide by 3 to obtain a mean of 10 cm.
Using the worked example as supplied data, predict the effect of changing one condition. Draw a labelled model, record your reasoning and identify a variable that would need controlling. No human, animal or microbial experiment is required.
No exact PhET model is claimed for this topic. Use diagrams and supplied-data reasoning instead.
A leaf has yellow patches
Colour patches can be directly recorded; the cause needs additional evidence.
10 cm
Add the three measured heights: 30 cm; divide by 3 to obtain a mean of 10 cm.
No
Biological variation and other conditions may explain a difference; replicated controlled evidence is needed.