1. Flowers have evolved specialized structures and colors to attract insects to aid in the reproduction of plants. 2. Flowers are composed of four whorls of modified leaves: sepals, petals, stamens, and carpels. Stamens and carpels are the essential reproductive parts. 3. There are two types of imperfect flowers - monoecious flowers have male and female reproductive parts on separate flowers of the same plant, while dioecious plants have only male or female flowers.

1. Plant
Reproduction

2. Introduction
• A flower has a set of adaptations
– Petals have modified leaves
– Entire flower is a highly modified branch
• Flower shape, scent, color attracts insects,
thereby ensuring the reproduction of the plant

4. Flower
• Function
– To produce seeds for reproduction

5. Terminology
• Whorl
– Arrangement of three or more leaves,
petals, or other organs radiating from the
plant
• Non-essential flower parts
– Not directly involved in reproduction
• Essential flower parts
– Directly involved in reproduction

6. Parts of the Flower
• Receptacle
– Base of the flower

7. Parts of the Flower
• Sepals
– Non-essential parts of the flower
– Compose the first whorl
– Collectively
known as the calyx

9. Parts of the Flower
• Petals
– Non-essential parts of the flower
• Compose the second whorl
• Collectively known as the corolla

11. Parts of the Flower
• Stamen
– Essential flower parts
• Compose the third whorl
• Male reproductive organ
–Anther : Produces pollen (contains
sperm cells)
–Filament : Supports the anther

14. Parts of the Flower
• Carpels
– Essential flower parts
– Compose the last, fourth whorl
– Usually fused to make a single pistil
– Female reproductive organ

15. Carpels vs. Pistils
• (A) shows a single pistil
consisting of several
fused carpels
• (B) shows several
pistils, each consisting
of a single carpel

16. Parts of the flower
• Female reproductive organ
– Ovary : Swollen base of the pistil (contains
ovules, which contain egg cells)
– Style: Stalk of the pistil
– Stigma: Tip of the pistil, sticky to capture falling
pollen

19. Types of Flowers
• Perfect
– Has both pistils and
stamens in the same flower
– Have all 4 whorls of modified leaves
• Imperfect
– Has either pistil or stamens in the same flower
– Missing one or more flower parts
– Two types
• Monoecious
• Dioecious

20. Imperfect Flowers
• Monoecious
– “Same house”
– Separate male and female flowers on the
same plant
– Example
• Corn

24. Imperfect Flowers
• Dioecious
– “Two houses”
– Flowers are all male or all female on the
same plant
– Example
• Ginko tree
–Most are male
–Female produces seeds with foul odor