Download
2 kinds of cones n.
Skip this Video
Loading SlideShow in 5 Seconds..
Conifers PowerPoint Presentation

Conifers

447 Vues Download Presentation
Télécharger la présentation

Conifers

- - - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

  1. 2 kinds of cones Conifers

  2. Male vs. Female Cones Male Pollen cones Female Seed cones immature

  3. Male Female immature

  4. Mature Immature

  5. “Naked” and “Covered”

  6. Reproduction • Scales • Male cones produce male gametophytes called pollen grain • Female cones (seed cone) produce female gametophytes called ovules(eggs) • Embryo – same idea as zygote (egg+sperm)

  7. Conifer Reproduction In this example we are using a pine cone seed coat Egg (n) Female gametophyte (n) Unfertilized ovule

  8. Unfertilized ovule

  9. Conifer Reproduction Fertilization initiates the transformation of the ovule into a seed Female gametophyte (n) Discharged sperm nucleus (n) Micropyle Male gametophyte (pollen grain) (n)

  10. Conifer Reproduction Compared to a single-celled spore, a seed is much more resistant and complex Seed coat Food supply Embryo (2n) Inside the seed (new sporophyte)

  11. Rise to the Angiosperms Seed plants appeared ~360 mya with the rise of the Gymnosperms Flowering plants (Angiosperms) – the other surviving lineage – appeared ~200 million years later