Angiosperns Phylum Anthophyta

General Characteristics Most general features shared with gymnosperms Flowering plants Considered the most evolved Flower is the reproductive structure Male parts: stamen - anther (makes pollen) and filament Female parts: pistil – stigma, style and ovary (contains ovules which make seeds)

General Characteristics Continued Two subclasses based on number of cotyledons (seed leaves) Dicotyledons (dicots) – two cotyledons Monocotyledons (monocots) – one cotyledon

Fertilization Pollination by insect and winds must occur first The pollen grain (male gametophyte) lands on the sticky stigma   Pollen tube grows down the style into the ovary Sperm nuclei unites with egg and a diploid zygote is formed Food storage tissue is fertilized separately (double fertilization) The zygote becomes a seed enclosed in a fruit

Adaptations Seed is enclosed in a protective fruit Have evolved methods of seed dispersal like animal vector Contain vascular tissue Fruit remains bitter until the seed is mature Angiosperms have coevolved with pollinator (symbiotic relationships)

Growth In gymnosperms and certain types of angiosperms, the only type of tissue that divides for growth is called meristem   There are two types of growth Primary growth – apical meristem divides at branch and root tips (height) Secondary growth – cork cambium and vascular cambium increase root and branch diameter (width)