1. 10.1 Sexual Reproduction in Flowering Plants

2. Review from 29.4! Sepals: surround unopened flower bud; whorl around petals when open Petals: size, shape, colour, odor used to attract pollinators

4. Stamen: composed of anther (sac-like container) and filament (slender stalk)  Male reproductive parts Pistil: female reproductive parts; vase-like shape  Stigma (enlarged, sticky knob), Style (slender stalk), and Ovary (enlarged base, contains ovules)

6. Perfect Flower (Bisexual): has all parts (sepals, petals, stamens, and a pistil) Imperfect Flower (Unisexual): missing some parts  Staminate Flowers: only have stamens  Pistillate Flowers: only have pistils Monoceious: staminate and pistillate flower on one plant Diocecious: staminate and pistillate flower on separate plants

8. Involves 2 generations: sporophytes and gametophytes  Diploid sporophytes produce haploid spores through meiosis

10. Heterosporous – ovules (pistil) produce megaspores; anthers (stamen) produce microspores Microspores  pollen grains (sperm- containing microgametophyte or male gametophyte) Megaspores  egg-containing embryo sac (megagametophyte or female gametophyte) Fertilization  Zygote  Embryo within seed  Germination  Growth of new sporophyte plant!

11. In ovules...  megaspore undergoes meiosis  produces 4 haploid megaspores  3 megaspores disappear, remaining 1 undergoes mitosis  Results in megagametophyte (embryo sac)  cytoplasm differentiates and produces polar nuclei (2 nuclei in centre, 3 at each opposite end)

13. In anthers...  Pollen sacs contain microspores  undergoes meiosis and produces 4 haploid microspores  microspores separate, each one produces a pollen grain  Nucleus undergoes mitosis, creating 2 nuclei called tube cell and generative cell

15.  When pollen is windblown or carried to the stigma of the same type of plant  Pollen grain germinates and develops a long pollen tube  Grows within style, reaching ovule in ovary  mitosis of generative cell produces 2 sperm (no flagella)

16. Double fertilization occurs...  One fertilizes egg, forming a zygote  Other fertilizes polar nuclei, forming endosperm nucleus

17.  Endosperm nucleus divides, forming endosperm (food for developing plant)  zygote develops into multicellular embryo  Ovule wall hardens, forming seed coat Seed consists of sporophyte embryo, stored food, and seed coat.  Ovary (and sometimes other floral parts) develops into fruit

19. Involves cell division, cellular elongation, and cell differentiation into tissues then organs. Development: set series of stages from a simpler to more complex form Cellular Differentiation: specialization of structure and function

20.  single-celled zygote under endosperm nucleus  endosperm nucleus divide by mitosis, producing mass of endosperm tissue  zygote divides  upper part = embryo, lower part = suspensor (anchors embryo and transfers nutrient)

21. Cotyledons (seed leaves) develop  embryo goes from heart-shaped to torpedo shaped  Shoot apex: shoot apical meristem = above ground growth  Root apex: root apical meristem = underground growth Endosperm is taken up by 2 cotyledons  Epicotyl is above cotyledon, contributes to shoot development  Hypocotyl is below cotyledon, contributes to stem development  Radiclecontributes to root devleopment Result: Embryo + stored food now contained in seed

23.  monocots = 1 cotyledon  monocot cotyledon rarely stores food  absorbs food from endosperm and passes it to embryo  dicot cotyledon usually stores food

24. Fruit: a mature ovary that usually contains seeds  Ovary wall thickens to become pericarp (fleshy)  apple, tomatoes, peaches  dry fruits have dry pericarps  legumes (peas and beans) split along 2 sides or seams

25.  Aggregate fruits develop from individual ovaries (blackberries, strawberries)

26.  adaptations to be carried by animals  clover has hooks to attach to fur  eaten by animals, then deposited in stool  buried by animals  ocean currents – ex. carry coconuts  wind – wooly hairs, plumes and wings

28. Germination: when an embryo grows into a seedling Dormancy: time during which no growth occurs, even when conditions are favourable Growth affected by presence of water and oxygen, temperature, dormancy period, etc.

29. Growth requires regulation (inhibitors and stimulators)  fleshy fruits – inhibitors that prevent growth until seeds are removed/washed  stimulators may include mechanical actions (ex. fire making seed coat permeable to water) Water uptake causes seed coat to burst!

30. Dicot  2 cotyledons (seed leaves) shrivel up Plumule: epicotyl bears young leaves Dicot seedling breaks through ground...  Shoot is hook shaped  hypocotyl becomes part of stem  radicle develops into roots

31. Can also grow in the dark  Etiolation: stem elongates, roots/leaves are small, plant lacks colour  resumes normal growth when light becomes normal

33. Monocot  endosperm is food storage tissue (cotyledon has no storage role)  plumule and radicle covered in protective sheaths (coleoptile and coleorhiza)  burst through coverings when germination occurs