Topic 16: seed plants: gymnosperms Flashcards

• seeds changed the course of what

  plant evolution
• how long ago did seed plants originate

  360 million years ago
• what kind of plants are the dominant producers in most terrestrial ecosystems

  seed-bearing plants
• What does a seed consist of?

  an embryo and nutrients surrounded by a protective coat
• the domestication of seed plants allowed for what

  permanent human settlements
• what are shared, derived traits of seed plants (5)

  -reduced gametophytes-heterospory-ovules-pollen-seeds
• Where do the gametophytes of seed plants develop?

  within the walls of spores retained within tissues of the parent sporophyte
• non-vascular bryophytes: -gametophyte or sporophyte dominant?-sporophyte/gametophyte are dependant/independent?

  -gametophyte dominant-sporophyte dependent on the gametophyte
• seedless vascular plants: -gametophyte or sporophyte dominant?-sporophyte/gametophyte are dependant/independent?

  -sporophyte dominant-gametophyte independent
• seedless plants: -gametophyte or sporophyte dominant?-sporophyte/gametophyte are dependant/independent?

  -sporophyte dominant-sporophyte independent, gametophyte microscopic and dependent on the sporophyte
• what is the trend in the evolution of plants

  progressive reduction in size and independence of the gametophyte, and the increasing role of the sporophyte
• almost all seedless plants are what? but all seed plants are what?

  − Almost all seedless plants are homosporous, but all seed plants are heterosporous
• what is heterosporous

  produce two sizes of spores: megaspores and microspores.
• Microsporangia produce what

  microspores that give rise to male gametophytes.
• Megasporangia produce what

  megaspores that give rise to female gametophytes.
• Are spores dispersed in seed plants?

  no, theyre retained within sporophyte
• what does an ovule consist of (3)

  -megasporangium (2n)-megaspore (1n)-one or more protective integuments (2n)
• how many integuments does gymnosperms have


  one
• how many integuments do Angiosperm ovules usually have

  two
• what do ovules develop into after fertilization


  seeds
• what gives rise to male gametophytes

  microspores
• what gives rise to female gametophytes

  megaspore
• megasporangium 2n makes megaspore 1n via what

  meiosis
• megasporangium wrapped in what

  integuments 2n
• pollination triggers what

  the development of female (mega)gametophyte (1n)
• what are female gametophytes reduced to in angiosperms

  few nuclei and cells (embryo sac)
• how many female gametophytes are in gymnosperms

  several thousand cells
• what are contained within pollen grains

  microspores that develop into male magetophytes
• pollen grains are coated with what

  sporopollenin
• how does sporopollenin protect the pollen grains (3)

  withstands desiccation, UV, and physical damage
• in pollen grains, where do male gametophytes go

  to ovule
• microspore is not dispersed, it developes into what


  pollen grain
• microspores undergo what to produce tiny male gametophytes

  mitosis
• pollen grain contains what

  the male gametophyte that develops within the spore wall
• each male gametophyte has at minimum what

  generative cell and a tube cell
• after pollination what will a generative cell and a tube cell turn into

  sperm nuclei and a pollen tube
• pollen eliminates the need for what

  water for fertilization
• what is pollination

  transfer of pollen to part of a seed plant containing ovules
• if a pollen grain germinates, it gives rise to what

  a pollen tube that discharges two sperm nuclei into female gametophyte within the ovule
• a seed develops from the what

  whole ovule