1 / 13

Chapter 38

Chapter 38. Angiosperm Reproduction. Angiosperm Reproduction. Angiosperms have 3 unique features: Flowers, Fruits, & Double Fertilization Microsporangia Pollen sacs in the anther Diploid cells = meiosis  male gametophyte (pollen) Pollen has 2 haploid nuclei

perrin
Download Presentation

Chapter 38

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Chapter 38 Angiosperm Reproduction

  2. Angiosperm Reproduction • Angiosperms have 3 unique features: • Flowers, Fruits, & Double Fertilization • Microsporangia • Pollen sacs in the anther • Diploid cells = meiosis  male gametophyte (pollen) • Pollen has 2 haploid nuclei • Tube nucleus – 1 sperm develops into a pollen tube • Generative nucleus – divides into 2 sperm cells which remain inside the pollen tube

  3. Ovary • Ovules form with a diploid cell • Soon 4 haploid megapsores form • Eventually get 8 haploid nuclei, but only 3 are most important • 1 haploid nucleus = egg • Will combine with sperm nucleus to form the zygote • 2 other nuclei are called polar nuclei • Polar nuclei will fuse with sperm nucleus to make 3n endosperm

  4. Watch Animation • 38-01.swf

  5. Pollination • Pollen lands on stigma • Pollen tube made from pollen grain • Pollen tube grows down into the ovary • When pollen tube reaches ovule, double fertilization occurs

  6. Double Fertilization • Double fertilization is the union of 2 sperm cells forming zygote & endosperm • Unique to angiosperms • 1 sperm fertilizes the egg  zygote • Zygote develops into the embryo  sporophyte • Other sperm combines with both polar nuclei = 3n nucleus • This 3n tissue  endosperm • Endosperm – food storing tissue in the seed

  7. After double fertilization • Ovule develops into a seed • Ovary develops into fruit which encloses the seed • Fruit protects the enclosed seed • Fruit aids in dispersal by wind or animales • Seed coat – protects embryo & its food supply • Radicle – embryonic root • Epicotyl – shoot tip with pair of miniature leaves

  8. Seed • As the seed matures, It goes dormant • Low metabolic rate, growth and development are suspended • Seed resumes growth given suitable environmental conditions for germination

  9. Asexual Reproduction in Plants • Asexual reproduction in plants is called vegetative reproduction • Fragmentation • Type of vegetative reproductive • When a part of the parent plant is separated and then generates into a new plant, genetically identical to parent plant • Self-fertilization is another means of asexual reproduction

More Related