I. Seed Plants A. Seed 1. plant embryo (sporophyte) 2. durable coat - water tight 3. stored energy source 4. adaptation for terrestrial life (meets these criteria): a. dispersal b. dormancy c. germination (well-timed) d. nourishment (through the seedling stage)

B. Sporophyte is dominant 1. gametophyte is dependent on the sporophyte 2. pollen grains a. male gametophytes b. sperm inside of “shell”

3. ovule a. contains megaspore (egg) b. gymnosperms - ovule not enclosed by sporophyte tissue - “naked seed” - evolved first

c. angiosperms - ovule(s) enclosed by carpel

4. pollination - no need for water

C. Gymnosperms 1. conifers are most familiar - cones - gametophytes grow inside the cones

2. ginkgo 3. cycads - predominant in Jurassic period 4. desert shrubs - Ephedra - Welwitschia

5. life cycle a. ovules on ovulate (seed) cones

5. life cycle a. ovules on ovulate (seed) cones b. pollen cones (male)

5. life cycle a. ovules on ovulate (seed) cones b. pollen cones (male) c. pollen wind-aided

5. life cycle a. ovules on ovulate (seed) cones b. pollen cones (male) c. pollen wind-aided - produced in large quantities

d. egg fertilized  zygote - usually occurs more than 1 year after pollination - seed = zygote + mature ovule - seeds are usually shed about 2 years after pollination e. delayed growth

II. Flowering Plants A. Angiosperms 1. 90% of plants 2. more specialized pollen delivery than gymnosperms

B. Flowers (pollination enhancers) 1. reproductive organs 2. petals attract pollinators

3. structure: 4 whorls (concentric circles) a. sepals (modified leaves) b. petals (attractors) c. stamens - anther at tip d. carpel - style - stigma (sticky at tip) - ovary (contains one or more ovules)

4. specializations a. nectar b. odor d. attract specific insects or birds c. colors

5. some angiosperms still rely on wind dispersal - grasses and some trees - typically lack attractants like colorful petals

C. Seeds - contain the new sporophyte form of the plant - in angiosperms can be produced within a few days after pollination

1. endosperm a. nutritious food source b. requires double fertilization - two sperm per pollen grain - one sperm fertilizes egg - one sperm fertilizes large diploid central cell of embryo sac - embryo sac is female gametophyte - forms triploid cell  endosperm

2. fleshy leaves (cotyledons) a. dicots - 2 seed leaves (cotyledons) - branched veins in leaves - 4 or 5 flower parts per whorl (occur in 4’s or 5’s)

2. fleshy leaves (cotyledons) a. dicots - 2 seed leaves (cotyledons) - branched veins in leaves - 4 or 5 flower parts per whorl - cotyledons absorb endosperm as seed develops

b. monocots - 1 seed leaf (cotyledon) - parallel veins in leaves - 3 flower parts per whorl (occur in 3’s)

b. monocots - 1 seed leaf (cotyledon) - parallel veins in leaves - 3 flower parts per whorl - cotyledon absorbs endosperm during germination

D. Fruit 1. from the ovary (surrounded by carpel)

D. Fruit 1. from the ovary (surrounded by carpel) 2. may be fleshy a. berries - include citrus, melons, cucumbers, squash, bananas

b. drupes - stone fruits

c. pomes - includes members of the rose family (although some members are berries) - apple - pear - quince - pomegranate

3. other specializations a. burrs b. coconuts (are drupes)

3. other specializations a. burrs b. coconuts c. wind adaptations - wings, plumes