EX 2 review

• Shared traits between Charophytes and Embryophytes

  Both are autotrophs and photosynthesize

  
  

  ONLY found in Embryophytes: Sporic life cycle
• 1. Major driving force behind plant evolution

  Retaining water its the major driving force behind plant evolution.

  1. Two specific adaptations plants have come up with for dealing with: Seeds, Vascular tissues, Xylem, Phloem, lignin
• What is Alternation of generation in plants?

  The alternation of a sexual and asexual phase in the life cycle of an organism.

  ADVANTAGES

  Allows for more flexibility in dealing with changing environments

  1. Haploid (asexuall) - Sporophyte
  2. Diploid (sexually) - Gametophyte
• Key characteristics go Bryophytes

  • Earliest land plants
  • Alternation of generations
  • Gametangia within tissue layers

  They do not have vascular tissues, seeds, roots, or meristems
• Key characteristics of Lycophytes and Monilophytes

  • Lignin
  • Vascular tissue
  • First leaves (lycophylls) (microphylls)
  • Sporophyte dominance

  Does not have seeds but has vascular tissue
• Key characteristics of gymnosperms

  • Ovules and seeds
  • Plants with naked seeds
  • All lack flowers and fruits of the angiosperms
• Four gymnosperm phyla and their key characteristics

  1. Coniferophyta (conifers)

  -Pines, cedars, spruces and most familiar gymnosperm

  1. Cycadophyta (Cycads)

  -Tropical/subtropical regions

  1. Gnetophyta

  -Only phyla with vessels in xylem -Have three unusual genera

  1. Ginkophyta

  -Only one remains -male/female reproductive structures form on different trees -Flagellated sperm
• Double fertilization

  • Female egg sac contains 6 haploid egg cells, one megaspore that has two haploid polar nuclei.
  • Important to Angiosperms because it gives rise to endosperm that provides nourishment.

  Endosperm tissue

  • Tissue that surrounds and nourishes the embryo in the seeds angiosperms. 


  Important to

  Humans: Endosperm is most nutritious part of the seed.

  Plants: Prevents plant from wasting energy on unfertilized seed.
• Difference between Gastrula and Blastula

  Gastrula: Sets up formation of outer ectoderm and inner endoderm germ layers -Has blastopore

  Blastula: Migration of cells- No blastopore

  Group of animals that forms blastula but not gastrula: Sponges
• Difference between 1.Diploblasts and 2.Triplobasts

  1. No Mesoderm
  2. Mesoderm 


  Embryonic germs found in both: Endoderm and Ectoderm

  Sorts of symmetry in both

  1. Radial Symmetry
  2. Bilateral Symmetry
• Coelom: Lined body cavity 


  Eucoelomates are more complex than acoelomates because they have a true coelom and acoelomates lack body cavity
• The difference between Protostome and Deuterostome development

  Protostome development: Mouth first + Anal

  Deuterostome development: Anal first + mouth
• What is the Cambrian explosion?: Rapid period in animal evolution and diversity.


  Why is it important to animal evolution?: most of todays animal phyla originated from it

  Causes: Rising levels of O2 and changes in predator prey relation
• What is mass extinction?: Major loss of diversity, global and regional climate change.


  Two major mass extinctions: K-T extinction and permian extinction.
• Phylum found within parazoa

  Porifera

  Common name: Sponges

  Key features: Lack true tissues and asymmetrical
• Why are flatworms flat

  They lack a body cavity
• Radiata two phylas:

  1. Chindaria
  2. Echinoderm 


  In common: they are both aquatic animals
• Two phyla within Lophotrocozoa

  1. Mollusca
  2. Platyhelminthe 


  Defining features

  1. complete digestive and gills for respiration
  2. They are triploblastic and bilaterally symmetrical
• Phyla within Ecdysozoa

  1. Arthopods- Exoskeleton made of chitin and invertebrates
  2. Nematoda- Primarily parasitical (round worms)
• Unique feature of Echinodermata

  Five point symmetry (radial symmetrical)
• Four characteristics that all chordates possess at some point in their life cycle? (humans, but then go away)

  1. Pharyngeal (gills)
  2. Notochord (flexible)
  3. Dorsal hollow nerve cord (develops into spinal)
  4. Post anal tail
• Two invertebrate within Phylum Chordata

  1. Urochordata
  2. Cephalochordata