Presentation on theme: "Reproduction in Flowering Plants"— Presentation transcript:
1Reproduction in Flowering Plants Objective:Describe the reproductive organs of the plantExplain the process of sexual reproduction in angiospermsDescribe the structure and function and structure of seedsHomework: Learn about and describe different methods of seed dispersal
2Quiz1. Why are the palisade and the spongy mesophyll called the ‘working layers’ of the leaf?What is cambium and what does it do?How does the arrangement of the stomata leading into the spongy mesophyll (filled with air spaces) ensure chlorophyll containing cells have a constant supply of carbon dioxide for photosynthesis?On board
4Sexual Reproduction in Angiosperms Plants reproduce sexuallyThe products of this sexual reproduction are seeds.These seeds are contained inside an ovary. Which develops into a fruit.
5Reproductive Parts Male reproductive organs (stamen): Anther: produces pollen grainsFilament: supports anther above female reproductive organsFemale reproductive organs (carpel):Stigma: sticky landing site for pollen grainsStyle: tube that leads down to ovaryOvary: contains ovules that develop into seeds
6Reproductive Mechanisms 9AdReproductive MechanismsPollen (male gamete) from one plant landson the stigma of another plant.This is called pollination.pollenstigma6
7Methods of Pollination Natural ReproductionPollination in angiosperms can happen by wind or animals.Animals can transfer pollen (bees) from one plant to the other.They are called pollinatorsPollen can be blown from one plant to another.Wind dispersal
10Selective breeding in plants 9AdSelective breeding in plantstexturesizeSelective breeding and cross-breeding are carried out on plants to produce flowers and crops with desirable characteristics…tastecolour10
119A Plant-breeding techniques Anne the plant breeder chooses two parent plants with useful characteristics.One plant will be the female parent. Anne removes the anthers and covers the flower with a bag. Why?female parentThe other plant is the male parent. Its anthers develop as normal.Anne collects its pollen and brushes it onto the female plant.collected pollenanthers removedShe puts the bag over the flower again. Later she collects the seeds and grows them to produce the new plant.
12From Pollen to Ovary The pollen grain grows a pollen tube 9AdFrom Pollen to OvaryThe pollen grain grows a pollen tubetowards the ovary, which contains the ovule and egg cell (female gamete).pollen tubeovary containing ovule12
139AdFertilizationFertilisation takes place when the ‘sperm’ nucleus from the pollen grain enters the egg cell. The resulting zygote eventually turns into a seed.pollen tube with pollen grain nucleusovuleEmbryo grows inside the ovule.egg cell13
14CompareWith your neighbour, discuss how the reproductive system in plants is similar to the reproductive system in humans.
15Quiz Name three different methods of seed dispersal. Chose one method and explain how it effectively disperses seeds away from plant.What are the male parts of the plant called?What is it called when pollen from one plant lands on the stigma of another plant.
16Comparing Plant and Human Reproductive Systems Male and Female organsMale Gamete is pollenFemale Gamete is egg produced in ovulePollen nuclei fuses with egg nuclei (fertiliation)Diploid zygoteZygote grows into embryoEmbryo grows inside protective seed coatCotyledons provide nourishmentMale or Female organsMale Gamete is spermFemale Gamete is egg produced in ovarySperm nuclei fuses with egg nuclei (fertilization)Diploid zygoteZygote grows into embryoEmbryo grows inside protective wombPlacenta provides nourishment
17Zygote to EmbryoThe zygote will grow through the process of mitosis to form an embryo (The ovule is now called a seed and is covered by a protective seed coat.)seedseed coatfood supply(cotyledon)embryo
18Fruit Formation Some plants produce fruit containing seeds. Fruit: Mature ovaryTissue surrounding the embryo develops into fruit.When the fruit is fully developed it drops off the plant, or is carried away by an animal.When fruit decomposes it releases the seed and germination can occur.
19Germination A seed requires moisture (water) to germinate. The as the embryo grows, the root and shoot break through the seed coat.Nutrients stored in the cotyledon provide nourishment and support early development