Kingdom Animalia

Question 1

Kingdom Animalia

Answer 1

multicellular – many specialized cells

Question 2

1st Theory of Origin of Multicellularity

Answer 2

1. unicellular protist → colony → early multicellular organism w/ specialized, interdependent cells (some do photosynthesis & some for locomotion) → later organism that produces gametes
2. results in radial symmetry

Question 3

2nd Theory of Origin of Multicellularity

Answer 3

• 2. early colony of protists; aggregate of identical cells → hollow sphere → beginning of cell specialization → infolding → gastrula (specialize in digestion)
     * results in radial symmetry
• “ontogeny recaptulates phylogeny” - means life history (including your embryology summarizes ancestry)
  
  • 1. e.g. human embryology – gills, tails show ancestry

Question 4

3rd Theory of the Origin of Multicellularity

Syncytial hypothesis

Answer 4

• Large syncytial single cell → internal barriers → more internal barriers
• results in bilateral symmetry