Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Reproduction in Flowering Plants WALT – Explain how plants reproduce Sexually Mr. Stuart Living Environment • Identify and draw, using a hand lens if necessary, the • sepals, • petals, • stamens, • anthers, carpels, • ovaries and • stigmas of one, locally available, named, insect-pollinated, dicotyledonous flower, Sexual Reproduction • Using the gametes from 2 parents to produce genetically unique individuals Flower • Sexual reproductive structure • Produces egg and sperm • Fertilization takes place inside the flower Which is the most accurate statement? The principal role of a flower in the life cycle of a plant is: • • • • (a) attracting insects (b) producing seeds (c) producing pollen (d) producing nectar Female reproductive organ Pistil/ Carpel *Stigma –top of the carpel, Sticky surface for pollen to stick to *Style – connects the stigma to the ovary *Ovary –contains ovules ( eggs) Male reproductive organ Stamen *Anther – produces sperm nuclei by meiosis. Sperm nuclei are enclosed by pollen grains. *Filament – holds the anther up Pistel = many Carpels • Female • Male 1) What features of flowers might attract insects? 2) Which part of the flowers become a the seed and be the fruit? Draw an accurate diagram of a flower and include both Male/ Female Organs • Pg 67 http://www.bbc.co.uk/bitesize/standard/biol ogy/world_of_plants/growing_plants/revisio n/4/ Pollination Pollination WALT – • Explain the Transfer of mature pollen grains from the anther to the stigma using -wind -insects -birds & other animals • Name the agents of pollination • Compare the different structural adaptations of • insect-pollinated and wind-pollinated flowers • Describe the growth of the pollen tube and its entry into the ovule followed by fertilisation (production of endosperm and details of development are not required) • and examine the pollen grains under a light microscope or in photomicrographs • Pollination as the transfer of pollen grains from the male part of the plant (anther of stamen) to the female part of the plant (stigma) Draw in your books • Cross Pollination *Self pollination –pollen from same flower *Cross pollination – pollen from a different flower - more variation Because nature doesn’t like self pollination, often it is rejected • When a pollen grain lands on the stigma, it sticks and a pollen tube grows down through the style to an ovule (egg) Wind v Insect Pollination • Wind pollinated flowers are different in structure from insect pollinated ones. • [You need to be able to explain the main differences. This table will help to make these clear for you] Insect pollinated flowers - rose sweet pea Wind pollinated flowers - ragweed Insect Pollinated Wind Pollinated Insect Pollinated Wind Pollinated Insect Pollinated Wind Pollinated large, brightly coloured small petals, often petals - to attract brown or dull green - no insects need to attract insects large, brightly coloured petals - to attract insects small petals, often brown or dull green - no need to attract insects often sweetly scented - no scent - no need to to attract insects attract insects often sweetly scented - to attract insects no scent - no need to attract insects usually contain nectar - to attract insects no nectar - no need to attract insects moderate quantity of pollen less wastage than with wind pollination pollen produced in great quantities - because most does not reach another flower wastage than with wind pollination flower pollen very light and pollen often sticky or spiky -smooth - so it can be blown to stick to insects in the wind and stops it clumping together wastage than with wind pollination because most does not reach another flower pollen often sticky or spiky - to stick to insects pollen very light and smooth - so it can be blown in the wind and stops it clumping together anthers firm and inside flower - to brush against insects anthers loosely attached and dangle out - to release pollen into the wind Insect Pollinated Wind Pollinated large, brightly coloured petals - to attract small petals, often brown or dull green insects no need to attract insects often sweetly scented - to attract insects no scent - no need to attract insects usually contain nectar - to attract insects no nectar - no need to attract insects moderate quantity of pollen - less wastage than with wind pollination pollen produced in great quantities because most does not reach another flower pollen often sticky or spiky - to stick to insects pollen very light and smooth - so it can be blown in the wind and stops it clumping together anthers firm and inside flower - to brush anthers loosely attached and dangle out against insects - to release pollen into the wind stigma inside the flower - so stigma hangs outside the that the insect brushes flower - to catch the drifting against it pollen Fertilization • The sperm travels through the pollen tube to the ovule. The sperm & egg fuse forming the zygote (fertilized egg) –this grows into the plant embryo (cells grow by mitosis) • The ovary and zygote (fertilized ovule) develop and ripen. *The ovule forms the seed and the ovary forms the fruit. • A fruit is a ripened ovary Germnination WALT – Understand the process of germination The plant embryo uses food stored in the cotyledon of the seed until it develops leaves for photosynthesis • Cotyledon – Leaf inside seed that supplies food to growing embryo Seedling micropyle –opening in ovule where pollen tube attached and sperm entered hilum –scar where ovule attached to ovary radicle –embryonic root Epicotyl – grows above the cotyledons and gives rise to the leaves. Hypocotyl –below the point of attachment of the cotyledon, develops into the stem. Parts of a seed • Dicot Seed coat Hypocotyl Epicotyl Cotyledons Endosperm • Monocot Seed coat Epicotyl Hypocotyl Cotyledon Radicle Seed Germination Monocot Dicot Epigeous Hypogeous Radicle Page 71 72 74 76 Question 1 2 5 1 2 3 4 5 1 2 3 1 2 3 4 5 Marks 1 1 1 2 1 2 3 3 1 1 1 3 2 1 1 1 This powerpoint was kindly donated to www.worldofteaching.com http://www.worldofteaching.com Is home to well over a thousand powerpoints submitted by teachers. This a free site. Please visit and I hope it will help in your teaching