20.2 classification of plants vascular cone-bearing plants conifers
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20.2 Classification of Plants
Vascular Cone-bearing Plants
Conifers
20.2 Classification of Plants
Seed plants include cone-bearing plants and flowering plants.
• Seed plants have several advantages over their seedless ancestors. – can reproduce without free-standing water, via pollination
– pollination occurs when pollen meets female plantparts
– seeds nourish and protect plant embryo
– seeds allow plants to disperse to new places
20.2 Classification of Plants
• Gymnosperms do not have seeds enclosed in fruit. – “Gymnosperm” comes from a Greek word meaning
“naked seed”– most gymnosperms are cone-bearing and evergreen.– pollen is produced
in male cones.– eggs are produced
in female cones.
– seeds develop on scales of female cones.
20.2 Classification of Plants
• Cycads are gymnosperms
– look like palm trees with large cones– grow in tropical areas
20.2 Classification of Plants
• Ginkgos are gymnosperms– only one species alive today, Ginkgo biloba– grown in gardens and used in urban landscaping
20.2 Classification of Plants
• Conifers are gymnosperms in phylum Coniferophyta.– most common
gymnosperms alive today
– includes pines, spruce, cedar, fir, and juniper
20.2 Classification of Plants
20.2 Classification of Plants
Life Cycle of a Conifer