Download Introduction to Animals

Bell Ringer
 What is the function of the chloroplast?
Objectives
• Identify shared characteristics in animals
• Distinguish radial and bilateral symmetry
• Summarize the importance of a body cavity in animals
• Identify how scientists determine evolutionary
relationships between animals
Characteristics of Animals
 Heterotrophy
 Mobility
 Multicellularity
 Diploidy
 Sexual reproduction
 Blastula Formation
 Tissue
Heterotrophy
 All animals are heterotrophs
 Animals cannot make their own food
Mobility
 Animals have the ability to perform rapid, complex
movements
 Animals move by using muscle cells
 Swim, walk, crawl, run, fly
Multicellularity
 All animals have more than one cell
Diploidy
 Diploidy-two copies of each chromosomes
 All animals have two copies of each chromosome. One
copy from mom and one from dad.
Sexual Reproduction
 Almost all animals reproduce sexually by producing
gametes.
 Sperm cells of all animals have a flagella and they are
highly mobile.
Blastula Formation
 Blastula- a hollow ball of cells
 Cells within the blastula eventually develop into three
distinct layers of cells
 Ectoderm
 Endoderm
 Mesoderm
Blastula
• Ectoderm- Outer layer of skin, nervous system, sense
organs
• Endoderm- Lining of digestive tract, respiratory,
system, digestive organs, urinary bladder
• Mesoderm- Most of the skeleton, muscles, circulatory
system, reproductive organs
Tissues
 The cells of all animals except sponges are organized
into structural and functional units called tissues
 Tissues- groups of cells with a common structure that
work together to perform a certain function
Bell Ringer
What are the three distinct
cellular layers that the
Blastula forms into?
Body Symmetry
 All animals have their own Body Plan.
 Different types of Body Plans
 Asymmetry
 Radial Symmetry
 Bilateral Symmetry
Asymmetry
 Asymmetry- irregular in shape.
 Asymmetry is the simplest body plan in the animal
Kingdom
 Example: Sponges
Asymmetry
Radial Symmetry
 Radial Symmetry- Body parts arranged around a
central axis.
 Most animals that exhibit radial symmetry are aquatic.
 Example: Starfish or Sea Anemone
Radial Symmetry
Bilateral Symmetry
 Bilateral Symmetry-A body design in which there
are distinct right and left halves.
 In Bilateral Symmetry there are




Dorsal Surfaces(Top)
Ventral Surface(Bottom)
Anterior End(Front)
Posterior End(Back)
Bilateral Symmetry
Bell Ringer
What are the three different
types of symmetries?
Cephalization
 Most bilaterally symmetrical animals have evolved an
anterior concentration of sensory structures and
nerves.
 This is called Cephalization
 Animals with cephalic ends are often active and mobile.
Cephalization
Internal Body Cavity
 Bilaterally Symmetrical Animals have three basic
internal body plans
 Acoelomates
 Pseudocoelomates
 Coelomates
 Coelom-Body cavity; a fluid filled space found
between the body wall and the digestive tract.
Acoelomate
Aceolomate-No Body cavity
Pseudocoelomate
 Pseudocoelomate-A body cavity that is
located between the mesoderm and
endoderm.
Coelomate
 Coelomate-Have a body cavity located
entirely within the mesoderm.
 Provides an internal space where mesoderm and
endoderm can be in contact during embryonic
development.
 This helped complex organs evolve, why?
Coelomate
 Earthworms are coelomates
 True coelom wraps around the digestive tract to protect
organs.
 Provides are firm base for animals muscles to push
against.
Body Segmentation
 Segmented animals are composed of repeating
segments.
Challenge
 Earth worms are segmented animals that can live
without certain segments, why do you think that is?
Phylogenetic Tree
 Kingdom Animalia contains 35 divions
 Phyla
 Scientists use a Phylogenetic tree to visualize
classification
 The animal kingdom can then be divided into
vertebrates and non-vertebrates