REPRODUCTION OF FLOWERING PLANTS REPRODUCTION OF FLOWERING PLANTS Copyright © 2009 Pearson Education, Inc.

The flower is the organ of sexual reproduction in angiosperms Sepals—enclose and protect flower bud Petals—showy; attract pollinators Stamens—male reproductive structures Carpels—female reproductive structures Student Misconceptions and Concerns 1. The development of the male and female gametophytes in flowers is rarely well understood by students who are more familiar with animals. A thorough review of the alternation of generations life cycle of plants is helpful before discussing the details of plant sexual reproduction. Teaching Tips 1. The authors note in Module 31.9 that Modules 17.9 and 17.10 provide important background information on the sexual life cycle of a flowering plant. If these modules have not been addressed previously, consider adding them to the Chapter 31 assignment. 2. More students will recall that stamens are the male organs if they emphasize the word’s last syllable: stamens. 3. The four main parts of a flower, which are modified leaves, represent additional examples of evolutionary remodeling.

The flower is the organ of sexual reproduction in angiosperms A stamen has two parts Anther—produces pollen, which house cells which develop into sperm Filament—elevates anther A carpel has three parts Stigma—site of pollination Style—“neck” that leads to ovary Ovary—houses ovules, which contain developing egg Student Misconceptions and Concerns 1. The development of the male and female gametophytes in flowers is rarely well understood by students who are more familiar with animals. A thorough review of the alternation of generations life cycle of plants is helpful before discussing the details of plant sexual reproduction. Teaching Tips 1. The authors note in Module 31.9 that Modules 17.9 and 17.10 provide important background information on the sexual life cycle of a flowering plant. If these modules have not been addressed previously, consider adding them to the Chapter 31 assignment. 2. More students will recall that stamens are the male organs if they emphasize the word’s last syllable: stamens. 3. The four main parts of a flower, which are modified leaves, represent additional examples of evolutionary remodeling. For the BLAST Animation Flower Structure, go to Animation and Video Files.

The development of pollen and ovules culminates in fertilization Pollination Transfer of pollen from anther to stigma Pollen is carried by wind, water, and animals Student Misconceptions and Concerns 1. The development of the male and female gametophytes in flowers is rarely well understood by students who are more familiar with animals. A thorough review of the alternation of generations life cycle of plants is helpful before discussing the details of plant sexual reproduction. 2. Students’ knowledge of sexual reproduction in animals often results in an expectation of similar processes in plants. The double fertilization typical of angiosperms requires extra time and attention to distinguish it from processes seen in animals. Teaching Tips 1. Plants that produce lightweight, windborne pollen are the major sources of allergies, because the pollen remains in the air longer than heavier pollen grains. Copyright © 2009 Pearson Education, Inc.

The flower is the organ of sexual reproduction in angiosperms Angiosperm life cycle overview Fertilization occurs in the ovule; the fertilized egg develops into an embryo encased in a seed The ovary develops into a fruit, which protects the seed and aids in dispersal The seed germinates under suitable conditions to produce a seedling, which grows into a mature plant Student Misconceptions and Concerns 1. The development of the male and female gametophytes in flowers is rarely well understood by students who are more familiar with animals. A thorough review of the alternation of generations life cycle of plants is helpful before discussing the details of plant sexual reproduction. Teaching Tips 1. The authors note in Module 31.9 that Modules 17.9 and 17.10 provide important background information on the sexual life cycle of a flowering plant. If these modules have not been addressed previously, consider adding them to the Chapter 31 assignment. 2. More students will recall that stamens are the male organs if they emphasize the word’s last syllable: stamens. 3. The four main parts of a flower, which are modified leaves, represent additional examples of evolutionary remodeling.

Ovary, containing ovule Mature plant with flowers, where fertilization occurs Figure 31.9B Life cycle of a generalized angiosperm.

Ovary, containing ovule Embryo Seed Fruit (mature ovary), containing seed Mature plant with flowers, where fertilization occurs Figure 31.9B Life cycle of a generalized angiosperm.

Ovary, containing ovule Embryo Seed Fruit (mature ovary), containing seed Mature plant with flowers, where fertilization occurs Figure 31.9B Life cycle of a generalized angiosperm. Germinating seed

Ovary, containing ovule Embryo Seed Fruit (mature ovary), containing seed Mature plant with flowers, where fertilization occurs Figure 31.9B Life cycle of a generalized angiosperm. Seedling Germinating seed

Foliage leaves Cotyledon Cotyledon Cotyledon Seed coat Figure 31.13A Pea germination (a eudicot). Seed coat

Bee vision of flower petals

Resulting Bee