Plants are living things. We can learn about them by observing their parts and recording changes over time. A seedling in a pot is a useful starting point: notice its leaves, the direction of its stem and the condition of its soil without repeatedly pulling it out.
Each part has a job
Roots usually hold a plant in the soil and absorb water and minerals. The stem supports the plant and helps transport substances. Green leaves use light energy to make food through photosynthesis. Flowers are involved in reproduction in flowering plants; fruits often protect seeds.
- Water is necessary, but a waterlogged pot can deprive roots of air.
- Soil supplies support and minerals; it is not the plant’s ready-made food.
A seed beginning to grow
Germination is the beginning of growth from a seed. Most seeds need suitable moisture, oxygen and temperature. Light requirements for germination vary between plants. After leaves develop, a green seedling needs sufficient light for healthy growth.
For a fair comparison, change one condition at a time. Keep the seed type and observation period the same. Record dates and visible changes rather than guessing which plant is healthier.
- Observe the first root, then the shoot and leaves.
- A labelled drawing can record changes more clearly than an unlabelled picture.
Put it into practice
A worked example
Why might two equally watered seedlings grow differently if one is kept in a dark cupboard?
- Compare the light available to each seedling.
- The seed initially has stored food, but a growing green plant needs light to make more food.
Answer: The seedling without enough light cannot continue healthy growth in the same way. It may become pale and weak.
Try it yourself
Have a go before revealing the answer.
Which part mainly absorbs water from the soil?
Show answer
The roots.
Answer: The roots.
Name two conditions usually needed for germination.
Show answer
Any two of suitable moisture, oxygen and temperature.
Answer: Any two of suitable moisture, oxygen and temperature.
Watch out for these
- More water is not always better for a plant.
- Do not say every seed must have sunlight to germinate; requirements vary.
Continue with official resources
Match these concept notes to your current textbook and syllabus. They are independent explanations, not official board publications.
