Plant Structure
Roots
Anchor the plant in the soil.
Absorb water and nutrients from the soil.
Store food for the plant
.
Stems
Support the plant above ground.
Transport water, nutrients, and sugars between roots and leaves.
Some store food or water.
Leaves
The main site for photosynthesis.
Absorb sunlight and carbon dioxide to produce sugars.
Release oxygen into the air.
Flowers
Reproductive structures of flowering plants.
Produce seeds through pollination and fertilization.
Attract pollinators like bees, butterflies, and birds.
Fruits
Develop from fertilized flowers.
Protect seeds and aid in their dispersal.
It can be fleshy (like apples) or dry (like nuts).
Flowering Plants (Angiosperms)
Angiosperms are plants that produce flowers, and seeds enclosed within a fruit.
They are the most diverse group of plants on Earth. Angiosperms can be annuals (live for one year), biennials (live for two years), or perennials (live for many years).
Example
Include roses, daisies, grasses, and trees like oak and maple.
Kingdom Plantae
Kingdom Plantae includes all plants, from tiny mosses to giant sequoias.
Plants are multicellular organisms with cell walls made of cellulose. They undergo photosynthesis to make food, using chlorophyll to capture sunlight. Most plants reproduce sexually, through the production of seeds, but some reproduce asexually. Plantae is essential for ecosystems, providing oxygen, food, and habitats for other organisms.
Plant Adaptations
Xerophytes are plants adapted to dry environments, with features like thick waxy coatings to reduce water loss.
Hydrophytes
are plants adapted to water environments, with features like floating leaves and airy stems.
Epiphytes
are plants that grow on other plants, often in rainforests, obtaining nutrients and moisture from the air.
Carnivorous Plants
are plants that trap and digest insects to supplement their nutrient intake, often found in nutrient-poor soils.
Plant Reproduction
Sexual Reproduction
Involves the fusion of male and female gametes.
Pollination: Transfer of pollen from the male reproductive organ (anther) to the female reproductive organ (stigma).
Fertilization: Fusion of the male gamete (sperm) with the female gamete (egg) to form a zygote, which develops into a seed.
Various means like wind, water, animals, or explosive mechanisms disperse seeds.
Asexual Reproduction
It involves producing new plants from vegetative parts like roots, stems, or leaves.
Examples include runners (like strawberry plants), bulbs (like onions), and tubers (like potatoes).
Plant Classification
Non-vascular Plants
Lack of specialized tissues for transporting water and nutrients.
Examples include mosses, liverworts, and hornworts.
Vascular Plants
Have specialized tissues (xylem and phloem) for transporting water, nutrients, and sugars.
Divided into two groups: Seedless vascular plants (ferns, horsetails) and seed plants (gymnosperms and angiosperms).
Gymnosperms
Produce seeds that are not enclosed within a fruit.
Examples include conifers like pine trees and spruces.
Angiosperms
Produce seeds enclosed within a fruit.
Further divided into monocots (one cotyledon in the seed) and dicots (two cotyledons in the seed).
The dominant group of plants on Earth includes flowering plants like roses, sunflowers, and wheat.
Importance of Plants
Oxygen Production
Plants release oxygen as a byproduct of photosynthesis, which is vital for the survival of all organisms.
Food Source
Plants provide food for humans and animals, including fruits, vegetables, grains, and nuts.
Ecosystem Stability
Plants play a crucial role in maintaining ecological balance by providing habitats, stabilizing soil, and regulating the climate.
Economic Importance
Plants are a source of materials like wood, fibers, and medicines, contributing to economies worldwide.
Aesthetic Value
Plants enhance the beauty of landscapes, gardens, and natural environments, improving the quality of life for humans.
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