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Gymnosperms and Angiosperms. Two types of seed plants. Plants that produce seeds are called “seed plants” Pine trees and apple trees are both seed plants. Gymnosperms!. Definition: A seed plant that produces “naked seeds”
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Gymnosperms and Angiosperms Two types of seed plants
Plants that produce seeds are called “seed plants” • Pine trees and apple trees are both seed plants
Gymnosperms! Definition: A seed plant that produces “naked seeds” • They are called “naked” because they are not enclosed by a protective fruit • No fruit because no flowers! Characteristics: • Many have needle-like or scale-like leaves • Deep growing root system • Very ancient – been on earth about 360 million years
4 types of gymnosperms survive today • Cycads • Grow mainly in tropical and subtropical areas • Look like palm trees with cones • Conifers (means cone-bearing plant) • Largest group of gymnosperms • Most are evergreens
4 types of gymnosperms survive today • Ginkgoes • Many species alive millions of years ago • Only one survives today (Ginkgo biloba) 4) Gnetophytes • Live in hot deserts and tropical rain forests • Can be trees, shrubs, or vines
Reproduction in Gymnosperms **Look at the picture on page 275 in your book** 4 Steps: • Pollination • Transfer of pollen (sperm) from male cone to female cone • Pollen carried by wind • Fertilization • Sperm cell fertilizes the egg cell • Fertilized egg develops into embryo part of the seed • Seed Development • Seed matures, can take up to 2 years! • Seed Dispersal • When seeds are mature the wind carries seeds away.
Angiosperms! Definition: A seed plant that produces flowers, which turn into seeds that are enclosed in fruit
The Structure of Flowers A flower is the reproductive structure of an angiosperm Reproductive Organs: • Pistil • Female part of the flower • Stigma = sticky tip • Style = connects stigma & ovary • Ovary = contains ovule • Stamen • Male part of the flower • Anther produces pollen • Filament holds up anther Pistil
The Structure of Flowers The other parts can play a role in reproduction! Non-reproductive parts: • Sepals • Protect the developing flower • Often green in color • Petals • Shape, size, and number are different from flower to flower Pistil • Petals help with pollination! • Colors and shapes attract pollinators • Pollinators include birds, bats, and insects • Wind can also pollinate flowers
Reproduction in Angiosperms **Look at the picture on page 279 in your book** 4 Steps: • Pollination • When a grain of pollen falls onto the sticky stigma • Fertilization • Sperm cell fertilizes the egg cell • Egg cell is inside an ovule which is in an ovary • Fruit Development • After fertilization, the ovary becomes a fruit • Seed Dispersal • Animals eat fruits that contain seeds and disperse the seeds
Types of Angiosperms Two major groups of angiosperms: • Monocots • Examples: grass, corn, lilies, tulips • Dicots • Examples: roses, maple trees, beans, apples “Cot” is short for cotyledon • Cotyledon = seed leaf