Section 22.2 Reproduction in Flowering Plants Standard: SC.912.L.14.7 Relate the structure of each of the major plant organs and tissues to physiological processes. EQ What are the functions of major plant tissues and organs? We will describe the reproductive organs and fertilization of flowering plants and compare and contrast pollination by animals and wind. I will label the parts of the flower after reading a power point presentation and viewing a flower dissection virtual lab. Chapter 43 Opener Amorphophallus titanium, also known as "corpse flower," has rarely been coaxed to bloom in the U.S. The central projection, called a spadix, is often over six feet tall and is filled with small male and female flowers.

How are these functions important for the survival of species? Flowers What are the functions of flowers? How are these functions important for the survival of species? Flower dissection Honeysuckle

Section 22.2 Reproduction in Flowering Plants What Is the Function and Structure of the Flower? Most Flowers Lure Animals that Pollinate Them. Flowers Are the Reproductive Structures of Angiosperms. Complete Flowers Have Four Major Parts. Pollen Contains the Male Gametophyte. The Female Gametophyte Forms within the Ovule of the Ovary. Pollination of the Flower Leads to Fertilization.

Flowers are distinguishing characteristics of angiosperms All fruits come from flowers Angion=vessel Sperma=seed Angiosperms have seeds contained in a vessel (developing ovary) Saguaro cactus Cherry Example flowers collage. Define angiosperm Apple Cattleya orchid Sunflowers

Gametophytes form “male” and “female” structures that produce sperm and egg cells.

Flower Parts Angiosperms bear male and female gametophytes on flowers.

Flower Parts Flowers are the reproductive structures of angiosperms, produced by the sporophyte generation.

Flower Parts Complete flowers have four major parts. Sepals - – located at base of flower; surround and protect the bud. Dicot sepals are green and leaf-like. Monocot sepals resemble petals. 2. Petals 3. Stamens 4. Pistil/Carpel FIGURE 43-5b A complete flower (b) The amaryllis is a complete monocot flower, with 3 sepals (virtually identical to the petals), 3 petals, 6 stamens, and 3 carpels (fused into a single structure). The anthers are well below the stigma, making self-pollination unlikely.

Flower Parts 2. Petals – located above sepals; usually brightly colored and fragrant (attract pollinators). 3. Stamens (male reproductive structures) – attached above petals. Each consists of a filament (stalk) and anther (produces pollen).

Flower Parts 3. Stamens Pollen grain = contains sperm cells that when it lands on female structure of another plant. Sperm burrow to egg and fuse to form a diploid zygote that becomes encased in a seed. Seed germinates to form a new sporophyte.

Flower Parts 4. Carpel/pistil (female reproductive structure) – centrally located Each consists of a sticky stigma (catches pollen), an elongate style, and a bulbous ovary containing one or more ovules. Ovules – contain eggs that develop into seeds. Ovary – contains and protect the ovules and develops into a fruit.

Seed Germination The development of a plant from a seed. Germination requires 3 conditions: Oxygen Water Warm temperatures Seed Germination – The development of a plant from a seed. Germination requires 3 conditions: Oxygen Water Warm temperatures

Complete-Incomplete Flowers Flowers are complete if they have all parts, and perfect if they have both male and female parts. Example: A tulip flower is complete (though the sepals are the same color as the petals) and perfect. Grass flowers: incomplete, usually imperfect (separate male and female flowers) lack one or more of the four major floral parts: example: Grass flowers lack both petals and sepals

The Male Gametophyte Pollen contains the male gametophyte. Pollen develops within anthers of diploid sporophyte plants. Pollen grains have tough protective coats that exhibit species-specific shapes and patterns. Pollen is dispersed by either animal pollinators or wind currents.

The Female Gametophyte The embryo sac is the female gametophyte and develops within the ovary of diploid sporophyte plants. Each ovary contains one or more ovules FIGURE 43-9 Wind-pollinated flowers The flowers of grasses and many deciduous trees are wind pollinated, with anthers (yellow structures hanging beneath the flowers) exposed to the wind. Petals are reduced or absent.

Pollination Pollination occurs when a pollen grain lands on the stigma of a compatible plant. Pollen grain absorbs water and germinates. Tube cell extends, forming a pollen tube that grows down the style. Generative cell divides (mitosis) to form two sperm cells Sperm cells follow pollen tube to the ovule.

Animal Pollinators Flowers enhance a plant’s reproductive success because animal pollinators transport pollen from plant to plant as they feed.

Animal Pollinators Wind pollination is inefficient because most pollen grains fail to reach their target. Flowering plants (angiosperms) evolved from gymnosperms. Flowers produce pollen and nectar that attract animal pollinators (bees, moths, butterflies, hummingbirds).

Now let’s start our Flower Dissection Virtual Lab! http://www.cuhk.edu.hk/ bio/IVPDL/

Exit Activity Summarize the development of fruit from a flower.

? Check Your Thinking ? Concept check: Some students confuse pollination with fruit dispersal. Understand and be able to explain the difference. Some students confuse seed germination with plant growth. Understand and be able to explain the difference.