Download Plant Growth and Development Lab

Plant Growth and Development Lab
OVERVIEW: A seed is a packaged plant. Within it is a set of instructions for growing a big
plant. The seed contains all the parts and materials needed to establish the plant in the
soil. How does a change from a seed to a plant take place? What are the functions of the
structures of the seed and the growing plant? What changing characteristics can you
observe?
PROCEDURE:
1. Obtain and examine the external features of a soaked bean seed. Look along one
edge and find a scar where it was attached to the pod during development
2. Remove the seed coat and examine the two fleshy halves, called the cotyledons,
and the embryo.
3. Take the cotyledon that does not have the embryo attached. Scrape on its surface
and apply a drop of Lugol’s iodine solution. Be careful with the sharp scalpel and the
irritating iodine. Keep both off your body and clothes.
4. Take the cotyledon with the embryo and examine it with a hand lens. The embryo
contains two tiny leaves and short epicotyls that becomes the stem. Opposite the
leaves is the radical that becomes the root.
5. Examine and compare bean seedlings that are 3, 10, 15 days old. Measure and
record the length of the roots and leaves. Describe the appearance of the seed coat,
cotyledons and true leaves, if present for each plant.
6. Obtain, examine and cut a soaked, germinating corn seed lengthwise with the
scalpel
7. Test the cut surfaces with a drop of Lugol’s iodine solution.
8. Examine and compare corn seedlings that are 3, 10, 15 days old. Measure and
record the length of the roots and leaves. Describe the appearance of the seed coat,
coleoptile and true leaves, if present for each plant.
9. Compare a 15 day old bean plant and a 15 corn plant. Record your observations.
10. Examine and draw the pea pod with the developing seeds
Clean up your lab station. Throw away all materials and wash off your table and lab
trays.
Analysis Questions:
1. What is the function of a seed coat?
2. What is the function of a connection between a parent plant and the developing
seed?
3. As a result of the Lugol’s test, what food is contained in the cotyledons?
4. What is the function of the cotyledons? Is it the same in the corn and the bean?
5. Where did the energy originally come from that formed the cotyledons?
6. What part of the plant becomes established first? Why?
7. Where are the first leaves of the 10 day old bean seedling located?
8. What has happened to the cotyledons of the 15 day bean seedling?
9. Where is the seed coat in the 15 day old bean plant?
10. Which part of the embryo developed into the stem?
11. How are the first 2 leaves above the cotyledons arranged on the stem?
12. How does the corn develop differently than the bean?
13. What happens between the 3rd and 10th day of corn development?
14. How are the 15 day old bean and corn plant different?
15. What travels from the pea plant to the developing pea seeds through the veins?
CONCLUSION: - In your lab book answer the analysis questions; write out a conclusion
paragraph for this experiment. As a guide to completing your conclusion make sure you
answer the questions in the overview.