Flowers and Seeds
1. Why do plants produce flowers?
2. In the table below, list the names of the parts of a typical flower and the functions of each part. The first letters of the flower parts are provided following the order in the book on pages 40 and 41.
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The parts in our list numbered 3 through 7 are referred to as the "male" part of the flower, because they produce the male sex cell called the "sperm."
The parts in our list numbered 8 through 12 are referred to as the "female" part of the flower, because they produce the female sex cell called the "egg."
A new seed is formed (a new plant is produced) when the sperm combines with the egg in the ovary. |
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3. What is required for sexual reproduction to take place in flowers? What happens during fertilization in flowers?
(see the table above)
4. Why does pollen usually have to travel some distance before pollination occurs?
Many plants do not self-pollinate. The pollen must be carried to another flower of the same species.
5. What are the two main agents of pollination?
6. If a plant has tiny flowers, how are its pollen grains probably spread?
wind
7. If a plant has large, colorful flowers, how are its pollen grains probably spread?
8. How do flowers “advertise” and how do they “bribe” insects?
a. “advertise” –
b. “bribe” - nectar
9. In the space below, draw a typical flower and label 12 of the parts listed in the table above in #2.
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stigma B. anther C. petals D. sepal E. ovary F. stem G. ovules & eggs H. filament |
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The function of a flower is reproduction.
(The plant is reproducing itself by making seeds). The typical flower has sepals (D) and petals (C) which surround and protect the functional, seed-making parts. The rounded ovary (E) in the lower center of the diagram holds the ovules and eggs (G) which will become seeds after they are fertilized by pollen. Pollen is produced on the anther (B) and is carried by wind or pollinators to the stigma (A). A sperm cell in the pollen travels from the stigma to the ovary where it combines with an egg to form a new seed containing an embryo and cotyledons surrounded by a seed coat. |
A more complete explanation and an animation of seed formation is found here.
