In-Depth Notes on Plant Biology

Biotic Factors: Living components in an ecosystem that can affect the organisms within it.
- Bacteria
- Archaea
- Fungi
- Animals
- Plants
- Protists
Abiotic Factors: Non-living chemical and physical parts of the environment.
- Air
- Salinity
- Soil
- Temperature
- Light
- Water
- Minerals
- pH
- Humidity

Nonvascular Plants: Do not possess a well-developed system for transporting water and food.
- Characteristics:
- No true roots, stems, or leaves.
- Nutrients absorbed directly from the environment and passed cell to cell.
- Generally small in size.
- Examples: Mosses, liverworts, hornworts.
Vascular Plants: Have a complex system for transporting water and nutrients.
- Vascular Tissue:
- Xylem: Transports water and minerals.
- Phloem: Transports food (sugars).
- Functions of plant parts:
- Roots: Absorb water and nutrients from the soil, anchor the plant.
- Leaves: Photosynthesis (produce food) and transpire (release water vapor).
- Stems: Transport nutrients and water between roots and leaves.

Transpiration: The process where water is absorbed by roots and evaporates from leaves. It is carried through the xylem.
Translocation: Movement of organic nutrients, mainly sucrose, from the leaves to other parts of the plant via the phloem.
Characteristics of Xylem and Phloem:
- Xylem:
- One-way flow (upwards).
- Consists of thick-walled vessels supported by lignin.
- Phloem:
- Two-way flow (can move in both directions).
- Contains perforated end walls between cells.

Key parts of flowers:
- Stamen: Male part, composed of an anther (produces pollen) and a filament.
- Pistil: Female part, composed of stigma (receives pollen), style, and ovary (develops into fruit).
- Petals: Attract pollinators, part of the corolla.
- Sepals: Protect the flower before it opens, part of the calyx.
Types of Flowers:
- Ray Flowers: Often found in composite flowers like daisies.

Asexual Reproduction: Produces offspring exactly like the parent (clones).
- Methods include:
- Cuttings
- Tubers
- Runners
- Bulbs
Sexual Reproduction: Involves the fusion of male and female gametes leading to seed formation.

Main parts of seeds:
- Seed Coat: Protects the seed.
- Embryo: Developing plant.
- Endosperm: Provides nutrition to the developing plant.
Germination: The process of a seed sprouting into a new plant. Requires moisture and appropriate conditions.

Angiosperms: Flowering plants with seeds enclosed in fruits.
- Divided into two main groups:
- Monocots: One cotyledon.
- Dicots: Two cotyledons.
Gymnosperms: Cone-bearing plants with exposed seeds. Examples include:
- Pines (produce male and female cones).

Pollination Types:
- Self-Pollination: Pollen from the same plant fertilizes the ovule.
- Cross-Pollination: Pollen from one plant fertilizes the ovule of another.
Importance: Pollination is essential for the reproduction of flowering plants and leads to the production of fruits and seeds.