Presentation on theme: "making more of a species"— Presentation transcript:
1 making more of a species Plant Reproductionmaking more of a species
2 Two Forms of Plant Reproduction SexualReproductionAsexualReproductionMeiosis+FertilizationMitosis+VegetativePropagation
3 2 Types of Reproduction: Definitions2 Types of Reproduction:Sexual Reproduction – when a seed is made that will reproduce a plant. Requires 2 plants.Asexual Reproduction – Utilizing a part or parts of 1 parent plant. The new plant is a clone (exact duplication) of its parent
4 Sexual reproduction occurs in many kinds of plants in different ways Sexual reproduction occurs in many kinds of plants in different ways. Some plants form pollen that fertilizes eggs in the flower or cone, others produce spores.
5 Angiosperms reproduce using their flower structure:
6 The petals attract insects and birds to encourage pollination. The stigma, style, and ovary make up the female structure – the pistil. The ovary houses the ovules (eggs) before and after fertilizationThe anther and filament make up the male structure – the stamen - that produces the pollen.
7 Summary: Stages of Reproduction pollination – the transfer of pollen from the stamens to the pistils of a flowerfertilization (seed production) – the joining of an egg cell and a sperm cellseed dispersal – moving seeds from one place to anothergermination – the sprouting of a plant from a seed
8 PollinationPollination is the transfer of pollen from anther to the stigma of the carpelself-pollination (same plant)cross-pollination (different plant; same species)Pollen grain germinates (forms pollen tube)Double fertilization occurs
9 Plant Reproduction Basics Sperm travels to embryo sac by way of a pollen tubeOnce sperm fertilizes egg, zygote becomes embryo (within ovule)Ovule develops into seedOvary becomes fruitGermination of seed creates new sporophyte (which develops into a mature organism)
10 POLLEN TUBE GROWTH AND FERTILIZATION Figure 40-14POLLEN TUBE GROWTH AND FERTILIZATIONPollengrainStigmaDoublefertilizationTube-cellnucleusPollen tubePrimaryendospermnucleus(3n)SpermStyleSynergidOvaryZygote(2n)Micropyle1. Pollen grain germinateson the stigma. Pollentube begins growingdown the style.2. The tube-cell nucleusmoves into pollen tube,and the generative cellnucleus divides by mitosisto form two sperm inpollen tube.3. Pollen tube completesgrowth toward the egg bypassing through microphyleand discharging the twosperm into a cell adjacentto egg.4. One sperm unites withegg to form zygote.The other fuses with thetwo polar nuclei to formendosperm (nutrient tissue).
12 Parts of a SeedEmbryo- The young multi-cellular organism before it emerges from the seedEndosperm- A source of stored food, consisting primarily of starchesSeed Coat- Consists of 1 or more protective layers that encase the seedCotyledon- A seed leaf that stores food in the form of starch and protein for use by the embryoEpicotyl- The portion of the embryonic stem above the point at which the stem is attached to the cotyledon(s)
13 Getting the seeds dispersed (moving them) Flowering plants have different adaptations to enable their seeds to be dispersed as far away as possible.The different methods of seed dispersal are…by windby animalsby waterby splitting open forcefully
14 GerminationOnce the seed has been dispersed, it must germinate in order to grow.Some seeds do not grow right away because they become dormant.Dormant – Resting stage, no active growth
15 Germination Germination – A seed sprouting or starting to grow To germinate the seed must be placed in certain favorable conditions. Seeds need:WaterAirTemperatureLight
18 Summary: Stages of Reproduction pollination – the transfer of pollen from the stamens to the pistils of a flowerfertilization (seed production) – the joining of an egg cell and a sperm cellseed dispersal – moving seeds from one place to anothergermination – the sprouting of a plant from a seed