| A | B |
|---|
| Phylum Anthophyta | flowering plants (antho – flower) |
| carpel | (parent diploid sporophytic tissue) at pollination |
| the “vessel” is the | carpel, which is a modified leaf |
| about 250,000 known living species | (dominant photosynthetic organisms on land) |
| Phylum Anthophyta 1. historically divided into two classes | dicots and monocots |
| nevertheless, by far most of the living angiosperm species are found within two monophyletic groups | eudicots and monocots |
| eudicots | most have embryos have two cotyledons (seed leaves) |
| annuals | (entire growth cycle in one year or less) |
| monocots | embryos have one cotyledon |
| Laurasia | North America, Europe, Asia |
| Gondwanaland | South America, Africa, Australia, Antarctica, India, New Zealand) |
| calyx – sepals | usually green, leaf-like, and protect immature flower |
| corolla – petals | usually colorful, attract pollinators; together with calyx called perianth |
| androecium – stamens | male reproductive structures |
| filament + anther | microspores produced within anther, shed as pollen |
| gynoecium | female reproductive structure |
| advanced: carpels fused | (called pistil) |
| ovary | swollen base with 1 to hundreds of ovules; develops into fruit |
| stigma | tip; sticky and/or feathery to catch pollen |
| style | usually present; separates stigma from ovary |
| nectaries may be present at base of pistil | secrete sugar, amino acids, and other compounds to attract pollinators |
| one nuclei from each group migrates toward center | these are polar nuclei |
| two layers of ovule | (integuments) |
| pollination | transfer of pollen to a stigma |
| some plants self-pollinate | (inbreeding) |
| double fertilization | one sperm unites with egg, forming zygote; • other sperm unites with polar nuclei, forming 3N primary endosperm |
| seed coat | tough, relatively impermeable |
| germination | breaking dormancy = resuming metabolic activity, growing out of seed coat; |
