Reproduction in Flowering Plants

The flower is a structure specialized for reproduction Sexual Reproduction in flowering plants involves meiosis and fertilization

Reproductive Organs The stamen is the male reproductive structure and consists of an anther and filament The filament holds the anther The anther produces monopolid cells by meiosis called pollen

Reproductive Organs The pistil is the female reproductive structure located in the center of the flower It consists of the : Stigma: which is at the top of the pistil and receives pollen

Style: supports the stigma, connects the stigma to the ovary Ovary: produces monoploid cells by meiosis in structures called ovules

1. stigma 2. anther 3. petal 4.style 5. filament 6. ovary 7. sepal

Pollination Pollination is the transfer of pollen from an anther to a stigma

Self-pollination: transfer within the same plant (less variation) Cross pollination: pollen is transferred from the anther of one plant to the stigma of another Can be due to wind, insects, birds water (color and nectar are attractants) Artificial pollination: pollen is transferred by humans

Fertilization Pollen lands on the stigma of a flower A pollen tube grows down the style to the ovary

The pollen tube penetrates the ovary and enters the ovule A monoploid sperm nucleus fuses with a monopoloid egg nucleus to form a zygote The zygote undergoes mitosis to become and embryo

The ovule becomes the seed The ovary becomes the fruit containing seeds

Seed Structure Seed coat: the outer layer that protects the embryo

Seed Structure The epicotyl develops into the leaves and upper stem The hypocotly develops into the stem The radicle develops into roots The cotyledons store food

Monocots have one cotyledon Dicots have 2 cotyledons

Seed Germination: the early growth of a plant embryo The embryo develops into a mature plant by : Mitosis Differentation Growth

Requirements for Seed Germination Proper temperature Moisture Oxygen DOES NOT REQUIRE SUNLIGHT!!!!