Various flowers in Reproduction in Plants – Class 7 Science Experiment

Chapter Name: Reproduction in Plants

Activity Name: Various flowers in Reproduction in Plants

Activity Description:

In this activity, students will collect various flowers, including Datura, Chinarose (Hibiscus), Cucumber, Bottle gourd, Tridax, Sunflower, Ipomea, etc. They will observe and compare the size and shape of these flowers.

The focus will be on studying the parts present in a flower (floral parts) using the example of a Datura flower. Students will dissect the Datura flower and identify its different floral parts, such as the thalamus, calyx, corolla, androecium (stamens), and gynoecium (pistil).

Required Items:

1. Various flowers (Datura, Chinarose, Cucumber, Bottle gourd, Tridax, Sunflower, Ipomea, etc.)
2. Notebooks for drawing and writing observations

Step by Step Procedure:

1. Collect the different flowers and observe their size and shape.
2. Take a Datura flower and hold it by its stalk (the slightly swollen head at the end).
3. Identify and draw the shape of the thalamus, which is the base where the parts of the flower are present.
4. Above the thalamus, observe the green tube-like structure called calyx, with sepals at the edges.
5. Carefully remove the fused sepals to reveal what lies beneath.
6. Identify the funnel-shaped corolla formed of fused petals. Count the free edges of the petals and note their color. Remove the corolla and draw it in the notebook.
7. Examine the androecium (male part) of the flower, which consists of stamens. Each stamen has an elongated filament and a bulb-like pollen sac or anther at the top. Count the number of stamens and draw their structure.
8. Move on to the gynoecium (female part) of the flower. Observe the ovary, style, and stigma. Draw the pistil and count the number of pistils present in the Datura flower.
9. Compare the flower parts of different flowers collected by recording observations in a table.
10. Also, observe different types of stamens and pistils from the collected flowers and make notes.

Experiment Observations:

Students will observe and record the following:

1. Size and shape of various collected flowers
2. Structure of the Datura flower, including thalamus, calyx, corolla, androecium (stamens), and gynoecium (pistil)
3. Number of stamens and pistils in the Datura flower
4. Differences in male and female flower parts among the collected flowers
5. Drawings of the dissected flowers and their respective parts

Note down your observations in below table format

Precautions:

1. Handle the flowers carefully during dissection to avoid damaging the floral parts.
2. Use clean tools to dissect the flowers to avoid contamination.
3. Observe and draw the floral parts accurately for proper analysis.

Lesson Learnt from Experiment:

Through this activity, students will learn about the different parts of a flower, including the thalamus, calyx, corolla, androecium (stamens), and gynoecium (pistil). They will understand the variations in floral structures among different flowers and how these structures play a crucial role in plant reproduction.