Plant Reproduction and Characteristics

Stamen: Male reproductive part of a flower.
- Filament: Long stalk that holds the anther.
  - Allows pollen to be accessible to wind or pollinators.
- Anther: Sac-like structure that produces pollen grains.
- Pollen grains: Produce sperm and protect it.

Pistil: Female reproductive part of a flower.
- Stigma: Tip of the pistil.
  - Sticky surface to collect pollen grains, easing pollination.
- Style: Stalk that holds the stigma up to allow for easier pollination.
- Ovary: Base of the pistil containing the ovules.
  - Becomes the fruit after fertilization.
- Ovules: Make eggs.
  - Become the seed after fertilization.

Flower: Adaptation for sexual reproduction in angiosperms.
- Attract pollinators with color, shapes, fragrances, and/or nectar.
Parts of flowers:
- Sepals: Modified leaves that enclose and protect the bud.
- Petals: Modified leaves that attract pollinators.
  - Emerge when the bud opens.
  - Variable in shape, size, and color.

Each seed contains a tiny plant.
- If a seed sprouts, or begins to grow, it will become a new plant.
A mature plant produces a flower.
- Pollination and fertilization take place.
- Each ovule within the flower's ovary contains a fertilized egg.
- Petals and stamens fall away.
- The ovary becomes the fruit, and each ovule becomes a seed.
- Eventually, the fruit ripens, and seeds are dispersed.

Pollination: Pollen, which contains sperm, travels to the stigma.
- Pollinators = animals or wind.
Fertilization: Sperm fuses with egg in an ovule of the ovary.
Seeds develop from the ovule after eggs are fertilized; seed is dormant.
- Dormant: Growth is stopped.
Fruit: Mature ovary of a flower.
- Protects dormant seeds and aids in their dispersal.
- Develops from the ovary after eggs are fertilized.
Seed dispersal: Mature seed dispersed to new habitat.
Germination: Young sporophyte begins to grow.
- Need water, air, and warm temperatures.

What is a Plant?
- Characteristics of plants include:
  - Multicellular eukaryotes
  - Photosynthetic autotrophs (photoautotrophs)
  - Store energy as Starch
  - Cell wall containing cellulose
  - Possess a Cuticle
  - Alternation of Generations
Photosynthetic autotrophs:
- Autotroph: Able to make its own food, producer.
- Photosynthesis:
 - Process of using light energy to make glucose $(C6H{12}O6)$ from $CO2$ and $H_2O$ .
 - $6 CO2 + 6 H2O rightarrow C6H{12}O6 + 6 O2$ (light is required).
 - Photosynthesis occurs in the chloroplasts of plant cells.
Chloroplasts:
- Organelles that contain chlorophyll, site of photosynthesis.
Chlorophyll:
- Green pigment in chloroplasts that captures energy from sunlight, allows photosynthesis to occur.
Store energy as starch:
- Starch: Polysaccharide (carbohydrate) made by plants.