Flowering Plant Introduction and Reproduction Lesson Overview Flowering Plant Introduction and Reproduction

Flowers and Fruits What are the key features of angiosperm reproduction?   Angiosperms reproduce sexually by means of flowers. After fertilization, ovaries within flowers develop into fruits that surround, protect, and help disperse the seeds.

Flowers and Fruits Angiosperms develop unique reproductive organs known as flowers, shown in the figure.   Flowers contain ovaries, which surround and protect seeds.

Advantages of Flowers Advantages of Fruits Flowers are an evolutionary advantage to plants because they attract animals that carry pollen with them to the next flower they visit. This means of pollination is much more efficient than the wind pollination of most gymnosperms. Advantages of Fruits After pollination, the ovary develops into a fruit, a structure containing one or more matured ovaries. The wall of the fruit helps disperse the seeds contained inside it. When an animal eats a fleshy fruit, seeds from the fruit enter the animal’s digestive system. By the time the seeds leave the digestive system, the animal may have traveled many kilometers.   By using fruit, flowering plants increase the ranges they inhabit.

Angiosperm Classification For many years, flowering plants were classified according to the number of seed leaves, or cotyledons, in their embryos. Those with one seed leaf were called monocots. Those with two seed leaves were called dicots.

Monocots and Dicots The differences between monocots and dicots include the distribution of vascular tissue in stems, roots, and leaves, and the number of petals per flower. The characteristics of monocots and dicots are compared below.

Reproduction in Flowering Plants Lesson Overview Reproduction in Flowering Plants

The Structure of Flowers What are flowers? Flowers are reproductive organs that are composed of four different kinds of specialized leaves: sepals, petals, stamens, and carpels.

The Structure of Flowers

Sepals and Petals Sepals: enclose the bud before it opens, and they protect the flower while it is developing. Petals: are often brightly colored, are found just inside the sepals to attract insects and other pollinators.

Male Parts of the Flower - Stamen Stamen: are the male parts of the flower—each stamen consists of a stalk called a filament with an anther at its tip. Anthers: are the structures in which pollen grains—the male gametophytes—are produced.

Female Parts of the Flower - Pistil Pistil: the female parts of the flower that contain a single carpel or several fused carpels which enclose the ovary, the style, and the stigma. Carpels: the innermost floral part that produces and shelters the female gametophytes and, later, seeds. Each carpel has a broad base forming an ovary, which contains one or more ovules where female gametophytes are produced.

Female Parts of the Flower - Pistil Style: a stalk that narrows out of the carpel and bridges to the stigma. Stigma: is a sticky or feathery structure at the top of the style that specializes in capturing pollen.