Question

Describe the procedures described throughout this laborotory activity:

10.1 Flowers external:

10 Seed Plants II: Angiosperms After completing this exercise, you will be able to 1. define heterosporous, angiosperm, fruit, pollination, double fertiliation, endosperm, aeed, germina tion, annual, biennial, perennial 2. describe the significanceo 3. identify the structures of the flower: 4. recognize the structures and events (those in boldface) that take place in angiosperm reproduction; 5. describe the origin and function of fruit and seed; 6. identify the characteristics that distinguish angiosperms from gymnosperms Introduction The angiosperms, Phylum Anthophyta, are seed plants that produce flowers. "Antho" means flower, and "phyta plant. The word angiosperm literally means "vessel seed and refers to the seeds borne within a fruit There are more flowering plants in the world today than any other group of plants. Assuming that numbers indicate success, flowering plants are the most successful plants to have evolved thus far The most important characteristic that distinguishes the Anthophyta from other seed plants is the pr of flower parts that mature into a fruit, a container that protects the seeds and allows them to be dispersed without coming into contact with the rigors of the external environment. In many instances, the fruit also contributes to the dispersal of the seed. For example, some fruits stick to fur (or clothing) of animals and are brushed off some distance from the plant that produced them. Animals eat others; the undigested seeds pass out of the digestive tract and fall into environments often far removed from the seeds' source Our lives and diets revolve around flowering plants. Fruits enrich our diet and include such things as apples, oranges, tomatoes, beans, peas, corn, wheat, walnuts, pecans. ., the list goes on and on. Moreover, even when we are not eating fruits, we're eating flowering plant parts. Cauliflower, broccoli, potatoes, celery, and carrots all are parts of flowering plants. Biologists believe that flower parts originated as leaves modified during the course of evolution to increase the probability for fertilization. For instance, some flower parts are colorful and attract animals that transfer the sperm-producing pollen to the receptive female parts As seed plants, and like gymnosperms, the angiosperms are heterosporous; that is, they produce two spore types. Review the diagram of heterosporous alternation of generations shown in Figure 9-1, page 138. Figure 10-15 epicts the life cycle of a typical flowering plant. Refer to it as you study the specimens in this exercise. Note: This exercise provides two alternative paths to accomplish the objectives described above, a traditional approach (10.1-10.2) and an investigative one (10.3). Your instructor will indicate which alternative you will follow. 10.1 External Structure of the Flower (About 20 min.) The number of different kinds of flowers is so large that it's difficult to pick a single example as representative of the entire phylum. Nonetheless, there is enough similarity among flowers that, once you've learned the structure of one representative, you'll be able to recognize the parts of most. 149

Answer 1

Heterosporous is a plant in which two kinds of spores are borne by the same plant

Angiosperm: (Angios: enclosed Sperm: seed), Angiosperm are the plants which bear enclosed seed.

Fruit: the part of plant structure which is developed from the ovary after fertilization.

Pollination: The transfer of pollen grain from anther to the stigma is called pollination.

Double fertilization: It is the fertilization process in which 2 male gametes are involved. One male gamete is fuse with the female gamete egg to form seed and second male gamete fuse with the polar nuclei to form triploid endosperm nucleus. The fusion occurs twice therefore it is called double fertilization.

Endosperm: It is the nutritive tissue developed from the polar nuclei after fusion with the male gamete. It is triploid and provides nutrition to the developing embryo.

Seed: It is the plant part which is developed from the ovule after fertilization.

Germination: It is the budding of a seed after it has been planted in soil and remained dormant for a certain period of time.

Annuals: Plants that performs their entire life cycle from seed to flower to seed within a single growing season.

Biennials: plants which require two growing seasons to complete their entire life cycle.

Perrennials:Plants that persist for many growing seasons.

2. Fruits protect developing seeds and promote their dispersal once they are mature.

3. The structures of flower consist of four floral whorl that is from outside to inside is the calyx corolla androecium and gynoecium.

4. In angiosperm reproduction takes by the fusion of male gamete and female gamete. male reproductive structure is the androecium and female reproductive organ is gynoecium. Male gamete is develop in the anther and female gamete is develop in the ovary. By pollination the male gamete is transferred to the female gamete and then the male sperm nuclei fuse with the female egg nucleus to form zygote and second male sperm nucleus is fuse with the two polar nuclei to form primary endosperm nucleus.

5. The fruit is develop from the ovary after fertilization and the seed is developed from the ovule after fertilization

Angiosperm: Seed is produced by flowering plants and is enclosed within ovary. The lifecycle of these plants are seasonal. Has triploid tissue. Present; single (monocots) or in a pair (dicots). Leaves are flat in shape. Hardwood type. Reproduction rely on animals. Reproductive system present in flowers (unisexual or bisexual). Double fertilization occurs in angiosperm.

Gymnosperm: Seed is produced by non-flowering plants and are unenclosed or naked. These plants are evergreen. Has haploid tissue. Leaves are scalelike and needle-like in shape. Softwood type. Reproduction rely on wind. Reproductive system present in cones and are unisexual

iarment carfel or styte Pistil ovaay ovule Cotola etal Calte- se epals fedicel Receptacle FIG: FLOWER