Chapter 9&10_Flowers,Fruits,Seeds

Overview
- Recorded lecture on chapters 9 and 10.
- Online or recorded due to interruptions from holidays and lab exam weeks.

Definition of Flowers
- Distinct reproductive structure of angiosperms (flowering plants).
- Flowers produce seeds contained in fruits.
- Often have brightly colored petals to attract pollinators.
Functions of Flowers
- Reproduction: Sexual reproduction organ of plants.
- Production: Gametes or sex cells are produced in flowers.
- Pollination: Transfer of pollen from anther to stigma of the same or different flowers.
Parts of a Flower
- Essential Parts (Reproductive)
  - Stamen: Male part; consists of anther and filament.
    - Anther: Produces pollen.
    - Filament: Supports the anther.
  - Pistil: Female part; includes stigma, style, ovary, and ovules.
    - Stigma: Sticky top that receives pollen.
    - Style: Stalk supporting the stigma.
    - Ovary: Contains ovules that develop into seeds after fertilization.
- Non-essential Parts (Accessory)
  - Peduncle: Stalk of the flower.
  - Receptacle: Base that holds floral organs.
  - Sepals: Leaf-like structures protecting flower buds (collectively called Calyx).
  - Petals: Colorful parts attracting pollinators (collectively called Corolla).
- Collective Terms:
  - Petals and sepals together are called Perianth.

Style: Holds the stigma, acts as the passage for pollen to reach ovary.
Ovary: Enlarged part of the pistil, where seeds develop; may become fruit.
Ovules: Contains female gametes, forms seeds after fertilization.
Fertilization Process
- Pollen lands on stigma → travels down pollen tube → fertilizes ovule.
- Double Fertilization occurs: One sperm fertilizes the egg, the other fuses with polar nuclei to form triploid endosperm.
Classification of Flowers
- Based on ovary type: Hypogynous, Epigynous, Perigynous.
- Complete vs. Incomplete: Complete has all essential parts; Incomplete is missing one or more.
- Imperfect Flowers: Have either stamens or pistils, never both (Pistillate or Staminate).
- Symmetry: Actinomorphic (radially symmetrical) vs. Zygomorphic (bilaterally symmetrical).
- Based on Origin: Determinate (from terminal buds) vs. Indeterminate (from lateral buds).
Pollinators: Wind, water, birds, insects (entomophilous), and bats.
Inflorescence: Clusters of flowers; can be indeterminate or determinate.

Fruits: Matured ovaries containing seeds; may also include adjacent parts.
Parts of Fruit:
- Pericarp (ovary wall): Exocarp (outer layer), Mesocarp (middle), Endocarp (inner).
- Funiculus: Channel connecting seed to fruit.

Classification of Fruits
- By origin: Simple (from single ovary), Aggregate (from multiple ovaries of one flower), Multiple (ovaries from several flowers).
- By pericarp structure: Fleshy (berries, drupe, pome) or Dry (dehiscent and indehiscent).
Fleshy Fruits: Different types such as berries (tomato, banana), drupes (mango, coconut).

Dry Fruits: Can be dehiscent (viable to open) or indehiscent (do not open).
- Dehiscent examples: Legume (peas), Follicle (milkweed), Capsule.
- Indehiscent examples: Achene (sunflower seeds), Nut (acorns).
Dispersal Mechanisms: Wind (anemochory), water (hydrochory), animals (zoocory), self-dispersal (autocory).

Review for Finals: Covers chapters 6 to 10, focusing on reproductive organs, fruits, and seeds.
Final Exam Date: December 5, 8-10 AM; rules about potential cheating aids, with incentives for creativity.
Ensure understanding of all topics discussed to prepare for the exam.