The document provides an overview of the key characteristics of the animal kingdom. It discusses how animals originated from the sea and are classified into phyla. The key characteristics of animals include being multicellular and heterotrophic, having specialized tissues, and reproducing sexually. The document describes the basic body plans of animals, including their germ layers, body cavities, and patterns of symmetry. It distinguishes vertebrates from invertebrates and covers the major animal groups.

1. EasyShiksha.Com - A Way of Simple Learning
Introduction to Animals

2. Origin and Classification
 The first animals probably arose from the
sea.
 Taxonomists have grouped animals into
several phyla based on evolutionary
relationships.
 Many taxonomist recognize 30 or more
animal phyla. We will investigate 11 phyla.
Ten of the phyla include invertebrates and
only Chordata includes the vertebrates.
EasyShiksha.Com - A Way of Simple Learning

3. Kingdom Animalia
 Animals are capable of more complex and rapid movements compared to
other kingdoms.
 Evolved from heterotrophic protists
 Most animals contain large numbers of cells.
 Humans contain 50 trillion cells.
 DNA is the most direct evidence of evolutionary relationships between
animals
EasyShiksha.Com - A Way of Simple Learning

4. Characteristics of Kingdom Animalia
 Multicellular Organization
 Cells without cell walls
 Heterotrophic
 Sexual reproduction and development
 Movement
EasyShiksha.Com - A Way of Simple Learning

5. Multicellular Organization
 Most important advantage of multicellularity:
 Individual cells can specialize in one life task.
 In most animals, there is a division of labor.
 Specialization is the adaptation of a cell for a particular function.
 Tissues are the organization of similar cells.
 Specialized cells can carry out their tasks
more effectively than cells that must do many tasks.
EasyShiksha.Com - A Way of Simple Learning

6. Animals are Heterotrophic
 They must obtain complex organic
material from other sources.
 Most accomplish this through
ingestion.
 Digestion is accomplished within
the animal. This process extracts
the carbohydrates, protein and
lipids from the food eaten.
EasyShiksha.Com - A Way of Simple Learning

7.  Functions as a mechanism for breaking down food into small molecules
 Single-celled organisms digest food within their body cells
EasyShiksha.Com - A Way of Simple Learning
Digestion

8.  Choanocytes (specialized cells) capture & digest food for sponges
Two types:
 Two-way digestive system
 One opening in for food to enter & leave
 One-way digestive system
 have a mouth and an anus
 Food enters the mouth, continues in one direction through the
digestive tract, and wastes leave through the anus
 Includes annelids, arthropods, & vertebrates
EasyShiksha.Com - A Way of Simple Learning
Digestive Systems

9. Sexual Reproduction
 Requires two parents
 Gametes are haploid
 Allows for genetic variation
 Most animals reproduce sexually using
internal fertilization
Asexual Reproduction
 Only one parent
 Produces offspring genetically identical to the
parent
Parthenogenesis:
 The eggs develop without being fertilized
 New offspring will be all female
 occurs in some fishes, several kinds of insects,
and a few species of frogs and lizards
 Female bees can reproduce both sexually and asexually.
 Hermaphroditic organisms produce both eggs and sperm,
but cannot fertilize their own eggs.
EasyShiksha.Com - A Way of Simple Learning
Reproduction

10. Sexual Reproduction and Development
 In most animals, the gametes are the ONLY haploid cells in the life cycle.
 Sexual reproduction restores the diploid number and increases genetic variation.
 During the developmental process, the zygote undergoes many mitotic divisions.
These identical cells must undergo differentiation.
 Differentiation is process of cell becoming different from each other and being
specialized.
EasyShiksha.Com - A Way of Simple Learning

11. Movement
 Most animal are able to move.
 The ability to move results from the
interrelations of two types of
tissues found only in animals:
nervous tissue and muscular
tissue.
 There are a few animals that are
sessile (immobile).
EasyShiksha.Com - A Way of Simple Learning

12. SESSILE SEDENTARY
MOTILE
Sponge Chiton
Cheetah
EasyShiksha.Com - A Way of Simple Learning

13.  Oxygen and nutrients are transported
 Two types:
 Open circulatory system
 Body tissues are bathed directly in fluid containing oxygen
 Closed circulatory system
 The blood always remains inside the blood vessels and never comes in
direct contact with the cells.
 The materials enter and exit the blood vessels through the walls
EasyShiksha.Com - A Way of Simple Learning
Circulatory System

14. Have some type of skeletal support
 Endoskeleton inside and made of cartilage &/or bone
 Grow inside the animal
 Exoskeletons found in arthropods
 Hard and encases the body
 Cover the outside of the body
 Limit size
 Must be molted making animal vulnerable to predators
 Hydrostatic skeletons: fluid-filled internal cavities
 Worms and echinoderms (starfish)
EasyShiksha.Com - A Way of Simple Learning
Support System

15.  Taking in O2 & releasing CO2
 Gases can diffuse across moist surfaces (earthworms)
 Gills filter O2 from water (aquatic animals)
 Lungs take O2 from air (terrestrial animals)
Gills
Lungs
EasyShiksha.Com - A Way of Simple Learning
Respiratory System

16.  Coordinates the activities of the animal’s body
 Neurons – nerve cells that transmit electrochemical signals
 Nerve net - network of neurons, very little coordination
 Ganglia – clusters of neurons; may serve as a simple brain in anterior end of
an animal
 Brain – control center at anterior end
EasyShiksha.Com - A Way of Simple Learning
Nervous System

17.  Invertebrates
 10 phyla
 95% of animals
 Chordates
 Notochord
 Dorsal nerve cord
 Pharyngeal pouches
 Postanal tail
 Vertebrates
 Include fishes, birds and mammals
Kingdom
Animalia
Invertebrates Chordates
Vertebrates
EasyShiksha.Com - A Way of Simple Learning
Animal Diversity

18. Atom Molecule or
compound Organelle
CELL Levels of Organization
Tissue
Organ
Life begins
Organ
system Organism
EasyShiksha.Com - A Way of Simple Learning

19.  Sponges are the ONLY animals that have just the cellular
level
 All other animals show these levels – cell, tissue, organ, and
system
 Cells may specialize (take own different shapes and
functions)
 Cells are held together by cell junctions to form tissues
EasyShiksha.Com - A Way of Simple Learning
Levels of Organization

20. What is the difference in a
vertebrate and an invertebrate?
A vertebrate is an animal with a backbone
and invertebrates do not have a backbone.
EasyShiksha.Com - A Way of Simple Learning

21. Animal Body Structure
Symmetry
Germ layers
Body Cavities
EasyShiksha.Com - A Way of Simple Learning

22.  Symmetry refers to the consistent overall pattern of structure of an animal.
 Animals have three patterns of symmetry.
 Asymmetry – no symmetry
 Radial Symmetry – similar parts branch in all directions
from a central point
 Bilateral Symmetry- similar halves on either side of a
central plane. (distinct left and right halves)
EasyShiksha.Com - A Way of Simple Learning
Symmetry

23. EasyShiksha.Com - A Way of Simple Learning
Patterns of Symmetry

24. Bilateral
Identify the Type of Symmetry
Bilateral
Radial
Radial
EasyShiksha.Com - A Way of Simple Learning

25.  Most animals have a dorsal, ventral, anterior and posterior side or orientation.
 Dorsal – top
 Ventral – bottom
 Anterior – head
 Posterior - tail
 Most animals exhibit cephalization, the concentration of sensory and brain structures in the
anterior. Animals with cephalization have a head!
EasyShiksha.Com - A Way of Simple Learning
Directional Terms

26.  Germ layers are fundamental tissue types found in
 all animals except sponges (no true tissues).
 Ectoderm: becomes skin and nervous system
 Mesoderm: forms liver and lungs
 Endoderm: forms muscle and other systems
EasyShiksha.Com - A Way of Simple Learning
Germ Layers

27. Body Cavities
 COELOM : a fluid filled space
that forms between the
digestive tract and the outer
wall of the body during
development.
EasyShiksha.Com - A Way of Simple Learning

28.  Acoelomate: no body cavity
 Pseudocoelomate: fluid-filled cavity
 Coelomate: defined cavities
EasyShiksha.Com - A Way of Simple Learning
Types of Body Cavities

29.  2 germ layers
 Ectoderm and endoderm
 not separated by a cavity
 least complex body plan
Acoelomate (without a coelom)
 Examples: sponges and cnidarians
 3 layer acoelomate
 endoderm, mesoderm and ectoderm
 not separated by a cavity
 Examples: flatworms
EasyShiksha.Com - A Way of Simple Learning

30. Pseudocoelom: fluid filled cavity between the gut and body wall
Cavity formed between mesoderm and endoderm
Body cavity only partially lined with mesoderm
Examples: roundworms and rotifers
EasyShiksha.Com - A Way of Simple Learning
Pseudocoelomate

31. Cavity completely lined with mesoderm
Most complex body plan
Examples: mollusks, annelids, arthropods, echinoderms, and
chordates
Similar to human body plan
EasyShiksha.Com - A Way of Simple Learning
Coelomate