Pop Quiz! 5. Gametophytes are a. haploid plants that produce spores. 4. Which of the following statements concerning fertilization in ferns is true? a. It occurs within the female structure. b. It requires water. c. The fertilization product is a seed. d. It occurs within the female structure; and It requires water. e. It occurs within the female structure; It requires water; and the fertilization product is a seed. 5. Gametophytes are a. haploid plants that produce spores. b. diploid plants that produce spores. c. haploid plants that produce gametes. d. diploid plants that produce gametes. e. diploid or haploid plants that produce gametes.

Pop Quiz! 6. Alternation of generations refers to the a. expression of recessive traits. b. presence of a diploid and a haploid generation in the life cycle of plants. c. presence of the different sexes in two different plants. d. occurrence of a sexually reproducing diploid stage followed by an asexually reproducing haploid stage during the life cycle of higher plants.

Reproduction Part 2 (lecture 16) (Gymnosperms & Angiosperms) PLANTS! Reproduction Part 2 (lecture 16) (Gymnosperms & Angiosperms)

First Seed Plants Gymnosperm: conifers vascular heterospory seeds male vs. female gametophytes seeds naked seeds (no fruit) pollen contain male gametophyte life cycle dominated by sporophyte stage coniferous trees you are familiar with are diploid reduced (microscopic) gametophyte reduction of gametophyte protects delicate egg & embryo in protective sporophyte protected from drought & UV radiation

Ragweed pollen…oh my itchy eyes! Pollen eliminated the water requirement for fertilization spread through wind & animal Ragweed pollen…oh my itchy eyes!

male female sporangium & pollen male (pollen) cones female cones pine embryo

Gymnosperm Life Cycle

First Flowering Plants Angiosperm: flowering plants vascular heterospory male vs. female gametophytes flower specialized structure for sexual reproduction seeds within fruit pollen life cycle dominated by sporophyte stage trees & bushes you are familiar with are diploid reduced (microscopic) gametophyte

Flower Modified shoot, modified leaves Male Female sepals petals Stamens Filament & anther Female Carpel Stigma, style, & ovary Anther Filament Stamen Stigma Style Ovary Carpel Sepal Petal Ovule sepals petals stamens carpel

Flowering Plant Pollination Pollination – transfer of pollen from the anther to a stigma If pollination occurs, a pollen tube forms The pollen tube transfers sperm to the ovule which will result in a zygote (new plant) and a 3n (triploid) nucleus that will form endosperm Endosperm is the nutrient storing tissue in a seed

Seed & Plant Embryo Seed offers… protection for embryo seed coat endosperm (3n) Seed offers… protection for embryo stored nutrients for growth of embryo cotyledons embryo (2n) cotyledons = “seed” leaves, first leaves of new plant

Double Fertilization Remember: 3 Features of the Angiosperm Cycle Flowers, Fruits, & Double Fertilization The Process: Pollination (pollen grain lands on stigma) Tube Nucleus (pollen tube produced down the style) Generative Nucleus (2 sperm form by mitosis) Enters ovary through micropyle 1 sperm fertilizes haploid egg to form zygote; other sperm combines with 2 polar nuclei to form 3n endosperm (food-storing tissue)

Angiosperm Life Cycle double fertilization polar nuclei pollen grains male gametophyte = pollen grain (haploid) dehiscence egg cell ovary sac sperm nuclei travel down pollen tube 3n endosperm female gametophyte = ovary sac (haploid) 2n zygote double fertilization 2n embryo new sporophyte in seed (diploid)

Monocots & Dicots Angiosperm are divided into 2 classes dicots (eudicot) 2 cotyledons (seed leaves) leaves with network of veins woody plants, trees, shrubs, beans monocots 1 cotyledon leaves with parallel veins grasses, palms, lilies

Pop Quiz! 1. The heterosporous condition led to evolution of a. gymnosperms and angiosperms. b. pollen grains and seeds. c. male and female plant parts. d. pollen grains and seeds in male and female plant parts. e. gymnosperms and angiosperms which bear pollen grains and seeds in male and female plant parts.

Pop Quiz! 2. Which of the following produces no seeds? a.Cycads b.Conifers c.Horsetails d.Ginkgos e.Tomato 3. Microspores mature into a.ovules. b.seeds. c.pollen grains. d.anthers.

Pop Quiz! 4. Gymnosperms a. were the first plants not to have swimming sperm and were therefore freed from the need for water to reproduce. b. are divided into two groups, the monocots and dicots. c. were the first plants to develop vascular tissues. d. were the first plants to develop flowers to attract insects.

Pop Quiz! 5. Which of the following statements about pine cones is correct? a. Cones are exclusively female structures. b. Cones are the result of pollination. c. One type of cone produces microspores. d. Seeds are enclosed in cones. e. One type of cone produces microspores; and seeds are enclosed in cones.