Chapter 33 Intro to animals Questions And
Answers 2026 Update!!!
Multicellular and heterotrophs
• Mobility (at least during part of the life cycle)
• Prevalent sexual reproduction
• Unique cell structure:
List the characters that define animals o No cell wall
o An extensive extracellular matrix provides
structural support
o Unique cell junctions hold cells in place and
facilitate
communication among them
invertebrates (evolved first; backbone is
Invertebrates
absent)
vertebrates vertebrates (have a backbone)
Morphological and developmental features Type of body symmetry
traditionally used to classify • Number of germ layers
animals • Specific features of embryonic development
Can be divided equally by
any
longitudinal plane
through the central
Radial symmetry (Radiata)
axis
• Often circular or tubular
in shape,
with a mouth at one end
, Bilateral symmetry (Bilateria) Can be divided along a
vertical
plane to produce two
halves
Answers 2026 Update!!!
Multicellular and heterotrophs
• Mobility (at least during part of the life cycle)
• Prevalent sexual reproduction
• Unique cell structure:
List the characters that define animals o No cell wall
o An extensive extracellular matrix provides
structural support
o Unique cell junctions hold cells in place and
facilitate
communication among them
invertebrates (evolved first; backbone is
Invertebrates
absent)
vertebrates vertebrates (have a backbone)
Morphological and developmental features Type of body symmetry
traditionally used to classify • Number of germ layers
animals • Specific features of embryonic development
Can be divided equally by
any
longitudinal plane
through the central
Radial symmetry (Radiata)
axis
• Often circular or tubular
in shape,
with a mouth at one end
, Bilateral symmetry (Bilateria) Can be divided along a
vertical
plane to produce two
halves
