Asexual Reproduction Versus Sexual Reproduction Asexual reproduction occurs when a portion of a plant develops into a separate new plant that is genetically identical to the original, or parent, plant. Sexual reproduction occurs when a plant’s sperm combines with a plant’s egg. The resulting zygote can grow into a plant that is a genetic combination of its parents. Lesson 3-1

Animals live their entire lives as diploid organisms Animals live their entire lives as diploid organisms. But plants alternate between haploid and diploid lives called alternation of generations. generations Lesson 3-2

Alternation of Generations (cont.) Meiosis produce haploid spores. Spores grow by mitosis to become the haploid generation of a plant. Then haploid generation produce haploid sperm or egg. These fuse during fertilization to form a diploid zygote which become the diploid generation of a plant. Spores haploid sperm Eggs zygote diploid Lesson 3-2

How Do Mosses Reproduce? Plants Non Vascular Mosses Vascular Seedless (Spores) Ferns Seed Non Flowering Gymnosperms Angiosperms Lesson 1-3

How Do Mosses Reproduce? Mosses have large haploid generations and small diploid generations. It uses spores, not seeds. Haploid Diploid Spores Lesson 3-3

How Do Ferns Reproduce? Plants Non Vascular Mosses Vascular Seedless (Spores) Ferns Seed Non Flowering Gymnosperms Angiosperms Lesson 1-3

How Do Ferns Reproduce? Ferns have large diploid generations and small haploid generations. It uses spores, not seeds. Diploid Haploid Spores Lesson 3-3

Reproduction in Seedless Plants (cont.) How do seedless plants such as mosses and ferns reproduce? Lesson 3-3

How do seed plants reproduce? Seed plants have large diploid generations and small haploid generations. The haploid generation is protected within the diploid generation. In seed plants, pollen produce sperm which fertilize an egg in an ovule during pollination. Diploid Haploid Pollen Ovule pollination Lesson 3-4

How do seed plants reproduce? (cont.) After fertilization, a seed is produced. A seed consist of: an embryo, its food supply, and a protective covering. Seed embryo food supply protective covering Lesson 3-4

How do seed plants reproduce? (cont.) Non-flowering seed plants produce male and female cones. Lesson 3-4

How do seed plants reproduce? (cont.) Flowering seed plants produce flowers which have either/both male (stamen) and female (pistil) reproduction organs. Lesson 3-4

How do seed plants reproduce? (cont.) The male reproductive organ of a flower is the stamen. Pollen grains form at the tip of the stamen in the anther. Lesson 3-4

How do seed plants reproduce? (cont.) The female reproductive organ of a flower is the pistil. Pollen can land at the tip of the pistil, or stigma. The ovary is at the base of the style. It contains one or more ovules. Lesson 3-4

How do seed plants reproduce? (cont.) The ovary, and sometimes other parts of the flower, will develop into a fruit that contains one or more seeds. The seeds can grow into new, genetically related plants that produce flowers, and the cycle repeats. Lesson 3-4

Lesson 3-4

Difference Between Spores, Pollen, Seeds Chromosomes Haploid Diploid Function Produce haploid generation Produce sperm Produce diploid generation Size ~0.001 cm ~0.01 cm ~0.1 to 30 cm Transported Water, air, gravity Water, air, insects Water, air, animals Lesson 3-4