Fruits And Seed Formation
Key Notes :
1. Introduction to Fruits and Seed Formation
- Fruits are mature, ripened ovaries of flowers.
- They enclose and protect the seeds during development.
- Seed formation is a result of the fertilization process in flowering plants.
2. Process of Fruit and Seed Formation
- Pollination
- Transfer of pollen grains from the male anther to the female stigma.
- Types:
- Self-pollination (same flower/plant).
- Cross-pollination (different plants).
- Fertilization
- Fusion of male and female gametes (in the ovule).
- Results in the formation of a zygote.
- Development
- Zygote develops into an embryo (seed).
- Ovule becomes the seed, and the ovary becomes the fruit.
3. Structure of a Seed
- Seed Coat: Protects the seed.
- Embryo: Contains:
- Plumule (develops into shoot).
- Radicle (develops into root).
- Cotyledons: Store food for the developing embryo.
4. Types of Fruits
- Simple Fruits
- Formed from a single ovary.
- Example: Mango, Pea.
- Aggregate Fruits
- Formed from multiple ovaries of a single flower.
- Example: Strawberry, Raspberry.
- Multiple Fruits
- Formed from ovaries of multiple flowers.
- Example: Pineapple, Jackfruit.
5. Importance of Fruits and Seeds
- Protection of Seeds: Fruits protect seeds from damage and desiccation.
- Dispersal of Seeds: Help in spreading seeds through animals, wind, and water.
- Food Source: Many fruits and seeds are edible and provide nutrients.
6. Seed Dispersal
- By Wind: Seeds like dandelion have lightweight structures.
- By Water: Coconut seeds float.
- By Animals: Juicy fruits attract animals; seeds are dispersed after consumption.
- By Explosion: Seeds are forcefully ejected (e.g., Pea pods).
7. Germination of Seeds
- The process where a seed develops into a new plant.
- Requires:
- Water (activates enzymes).
- Oxygen (energy production).
- Optimal Temperature (enzymatic activity).
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