Download Classifying Animals - Ms. Chui's science class

Classifying Animals
Section 3.4
Kingdom Animalia
• in the domain Eukarya
• defining features:
•
•
•
•
eukaryotic
multicellular
motile (can move) at some point in life
heterotrophic
• the most diverse of all kingdoms
• classified based on body and behaviour
Symmetry:
Asymmetrical vs. Symmetrical
Asymmetrical
Radial Symmetry
Bilateral Symmetry
Irregular body shape
with no symmetry
body can be divided
equally along any plane
body can be divided equally
along only one plane
e.g., sponges
e.g., most lower animals
e.g., most higher animals
Organisms with bilateral symmetry
have defined body locations:
Anterior
(front end)
Posterior
(back end)
Dorsal (back side)
Ventral (under side)
Tissue layers:
Diploblastic vs. Triploblastic
Developing embryos are made up of layers
of cells (“germ layers”).
Classification is
based on the
number of germ layers
in the embryo.
• Diploblastic – Two germ layers:
• endoderm and ectoderm
• e.g., most lower animals
• Triploblastic – Three layers:
• endoderm, mesoderm, ectoderm
• e.g., most higher animals
Body Cavity:
Acoelomate vs. Coelomate
Acoelomate: No coelom
e.g., lower animals
Coelom
Coelomate: Has a coelom
e.g., higher animals
:
(“see-lome”)
• fluid-filled or air-filled cavity found between the digestive tract
and outer body wall
• cushions internal organs
• acts as a form of skeleton for soft-bodied animals
• provides space for development and suspension of organ systems
Segmentation:
Non-segmented vs. Segmented
Segmentation:
• the division of the body into repetitive sections
(“segments”).
• allows specialization of body regions
• more efficient movement
Non-Segmented:
No segments
Segmented:
Has segments
Movement:
Sessile vs. Motile
• Sessile – Stationary in its
environment
• e.g, adult sponges
• Motile – Can move through its
environment
• e.g., jellyfish
Some animals (sponges, anemones) are motile as juveniles,
and sessile as adults.
Reproduction:
Asexual vs. Sexual
• Asexual – One parent only
• Sexual – Two parents
• Internal fertilization – Gametes combine inside the body
• External fertilization – Gametes combine outside the body
Practice: Classify Yourself!
a)
b)
c)
d)
e)
f)
Symmetry
Tissue layers
Body cavity
Segmentation
Movement
Reproduction