Transcript Animal Characteristics

Animal Characteristics
Characteristics
►Eukaryotic
►Multicellular
►Ways
of moving that help them
reproduce, obtain food and
protect themselves
►Have specialized cells that form
tissues and organs
►Animal cells do not have cell walls
Characteristics
►Adults
mostly fixed in size and
shape
►Heterotrophic
►Must digest food
Development of Animals
►Most
develop from single, fertilized
egg call a _________________.
►Males produce _________, females
produce ________.
►Fertilization occurs when an egg is
penetrated by a sperm
►Fertilization may be internal or
external
Development of Animals
► Unicellular
zygote divides by mitosis
► Embryo develops until blastula
formed
► Blastula develops into gastrula
 Inner layer of cells called
endoderm, develops digestive
organs
 Outer layer of cells called
ectoderm, develops into skin and
nervous tissue
Development of Animals
►Gastrula
develops until mesoderm
formed
►Mesoderm = muscles, circulatory,
excretory system
Symmetry
► Asymmetry
symmetry
– no
Symmetry
► Radial
– think equal
slices of pie
Symmetry
► Bilateral
– animals
have anterior,
posterior, dorsal and
ventral surfaces
Posterior – butt, bottom
Anterior – head, front
Dorsal – back side
Ventral – stomach side
Animal Protection and Support
► Exoskeleton
or endoskeleton
 Hard outer protection or inner skeleton to
protect
► Invertebrates
and vertebrates
 Without backbone vs. with backbone