Plant biology, perhaps the oldest branch of science, is driven by a combination of curiosity and need curiosity about how plants work need to apply this knowledge judiciously to feed, clothe, and house a burgeoning human population.

Plant Reproduction Alternation of Generations  Sporophyte (diploid) produces haploid spores via meiosis  Gametophyte (haploid) produce haploid gametes via mitosis  Fertilization joins two gametes to form a zygote

 Monocots and Dicots named for the number of cotyledons present on the embryo of the plant Monocots  Orchids  Palms  Lilies  Grasses Dicots  Roses  Beans  Sunflowers  Oaks

 Sporophyte (diploid) actual plant with flowers  Gametophyte (haploid) male: germinated pollen grain female: embryo sac  Fertilization joins two gametes to form a zygote

 Gametophyte dominant generation has both sexes and produces gametes  archegonia (eggs)  antheridia (sperm)  Fertilization sperm move along moss to find archegonia  Sporophyte grows on top of gametophyte sporangia is where spores are produced by meiosis

 Sporophyte produce spores via meiosis spores develop into young gametophyte  Gametophyte has both sexes and produces gametes  archegonia (eggs)  antheridia (sperm)  Fertilization similar to mosses

 Sporophyte produce gametophytes inside of cones Pollen cone (male)  produces microspore via meiosis Ovulate cone (female)  produces megaspores via meiosis  Fertilization pollen grains discharge sperm into egg

 Male Gametophyte pollen grain  microspores produced within the anther  divide once to produce two sperm cells  FemaleGametophye embryo sac  megaspore produced within the ovule  divide to produce three egg cells and 2 polar nuclei

 Pollen grain lands on stigma  Pollen tube toward ovule  Both sperm discharged down the tube  Egg and one of the sperm produce zygote  2 polar nuclei and sperm cell produce endosperm  Ovule becomes the seed coat  Ovary becomes the fruit

The most common anti-selfing mechanism in flowering plant is known as self-incompatibility, the ability of a plant to reject its own pollen Stigma Anther with pollen Stigma Pin flowerThrum flower

 The radicle is the first organ to emerge from the germinating seed  In many eudicots a hook forms in the hypocotyl, and growth pushes the hook above ground Foliage leaves Cotyledon Hypocotyl Radicle Epicotyl Seed coat Cotyledon Hypocotyl Cotyledon Hypocotyl

 Monocots use a different method for breaking ground when they germinate  The coleoptile Pushes upward through the soil and into the air Foliage leaves Coleoptile Radicle