Section 6.3:Kingdom Animalia

pg. 182-197

Part 1:Invertebrates

Animal Kingdom

• Includes the very small to the very large organisms on Earth.

• Animals:– are multicellular

eukaryotes– are heterotrophic– reproduce sexually

Animal Characteristics

These are used to classifyanimals into different phyla:1. The number of Germ Layers– “germ” = cells in early stages– Most have 3 layers: ectoderm

(outer), endoderm (inner) & mesoderm (middle)

2. Digestive Tract– Most animals use

extracellular digestion– Incomplete digestive tract :

only one opening (food & wastes use the same opening)

– Complete digestive tract : separate openings for food & wastes.

3. Body Symmetry– Asymmetrical Body : irregular shape (i.e.

sponges, who are the simplest animals)– Symmetrical Body : most animals are balanced in

their shape

Symmetry

There are 2 types of symmetry1. Radial (Fig. 6.17a, pg. 185)

2. Bilateral (Fig. 6.17b, pg. 185)

4. Development of a Coelom– Coelom = a fluid-filled body

cavity– The presence of a coelom

allows for the development of more complex organ systems.

– Animals with a coelom = coelomates

– Animals without a coelom = acoelomates

5. Reproduction– All animals reproduce sexually– Some also reproduce asexually– Some are hermaphrodites = have both male &

female reproductive organs

Invertebrates(95% of Animal Kingdom)

• Examples include: (see Table 6.2, pages 183-184)– sponges– sea anemones– jellyfish– coral– planarians– tapeworms– leech– slug– clam– octopus– starfish– sand dollars, etc.

Invertebrate Characteristics

• Lack of internal structures• Reproduction includes

sexual & asexual• Some are coelomate

(i.e. earthworm) & some are acoelomate (i.e. flatworm)

Invertebrate Characteristics

• Can have asymmetrical (i.e. sponges), radial (i.e. jellyfish) or bilateral body forms (i.e. earthworm).

There are over 30 phylaof invertebrates, but wewill look at the major eight.

8 Phyla of Invertebrates

1. Porifera2. Cnidaria3. Platyhelminthes4. Nematoda5. Annelida6. Mollusca7. Echinodermata8. Arthropoda

Phylum Porifera

• Means “pore-bearing”• Example: Sponges

Phylum Cnidaria

• Means “thistle”• Examples: Jellyfish, corals, sea anemones,

hydras

Phylum Platyhelminthes

• Means “flat, wide worms”• Examples: Tapeworms, flukes, planarians

Phylum Nematoda

• Means “thread-like”• Examples: Pinworms, hookworms

Phylum Annelida

• Means “ring”• Examples: Earthworms, leeches, tubeworms

Phylum Mollusca

• Means “soft-bodied”• Examples: clams, oysters, squids,

octopi, snails, slugs, scallops

Phylum Echinodermata

• Means “spiny-skinned”• Examples: starfish, sea cucumbers, sand

dollars, sea urchins

Phylum Arthropoda

• The MOST successful phylum!!• Over 1 million species have been identified.• Very diverse – some live at the bottom of the

ocean, and some float in the air.

Examples of Arthropods

• Include:– Insects– Spiders– Shrimp– Barnacles– Lobster– Scorpions

Arthropods…

• have jointed appendages• have bilateral symmetry• have a coelom• have a “tube within a tube”

digestive system• reproduce sexually

Why are Arthropods So Successful?

• Exoskeleton: – a rigid, jointed external skeleton – is waterproof and protects against water loss– they must shed their exoskeleton in order to grow.

Other Reasons Why They Are Successful…

• The nature of their body segments & attached appendages.

• Their well-developed nervous system.• Their structures & functions related to feeding

themselves.

Insects

• The most successful species on Earth.

• But Why???1. They have many adaptations

for feeding.2. Most are small in size,

allowing them to hide.3. They move quickly and many

have wings.

Insect Mimicry

• Some insects have an adaptation called mimicry.

• Mimicry: the ability to look like something else.

Two Short Videos

• Insect Mimicry

• Phylum Arthropoda “How Stuff Works”

Section 6.3: Part 1Review Activities

• Do the “Survey of Invertebrates” handout.• Go to lab to do the Investigation 6C on pages

188-189.