Chapter 2: Mollusks, Arthropods, and Echinoderms

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Chapter 2 Mollusks, Arthropods, and Echinoderms
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I. Mollusks

• A. Characteristics of Mollusks
• 1) Body Structure
• 2) Circulatory System
• 3) Obtaining Oxygen

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Eating 2)Movement 3) Special Qualities
Gastropods - -
Bivalves - -
Cephalopods - - -
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II. Arthropods

• A. Characteristics of Arthropods
• 1) Outer skeleton
• ? exoskeleton waxy, waterproof covering (outer
  skeleton)
• ? molting shedding their skin
• 2) Segmented body
• ? head, midsection, and hind section
• 3) Jointed appendages
• ? antenna sensory organs
• 4) Diversity
• ?over 1,000,000 species!

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• B. Crustaceans
• 1) Body Structure
• ? 2-3 body sections 5 or more pairs of legs 2
  pairs of antennae
• 2) Obtaining Food and Oxygen
• ?gills scavengers carnivores or herbivores
• 3) Life Cycle
• ?metamorphosis
• C. Arachnids
• 2 body sections, 4 pairs of legs, 0 antennae
• 1) Spiders
• ? eat by using their fangs like straws
• 2) Mites
• ? most mites are parasitic
• 3) Scorpions
• ?venomous stinger attacks prey
• 4) Ticks
• ? parasitic can carry Lyme disease

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• D. Centipedes and Millipedes

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III. Insects

• A. Body Structure
• 1) Head
• 2) Thorax
• 3) Abdomen
• B. Obtaining Food
• ? different mouthparts
• C. Life Cycle
• 1) Complete metamorphosis
• 2) Gradual metamorphosis

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Gradual Metamorphosis Complete Metamorphosis

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IV. Insect Ecology

• A. Insects and the Food Chain
• Food Chain 1) producers - make their own food
• 2) consumers - eat other organisms
• 3) decomposers - break down wastes and dead
  organisms
• Insects play key roles in food chains because of
  the many different ways that they obtain food and
  then become food for other animals.
• Insects can even be food for humans.
• B. Other Interactions
• Pollen Carriers - EX bees, beetles, flies
• Disease Carriers - EX mosquitoes and fleas
• C. Controlling Pests
• To try to control pests, people use chemicals,
  traps, and living things, including other insects
  (biological control).

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V. Echinoderms

• A. Characteristics of Echinoderms
• 1) Body Structure endoskeleton (invertebrate)
  radial symmetry
• 2) Movement water vascular system (tube feet)
• 3) Reproduction Life Cycle
• B. Diversity of Echinoderms
• 1) Sea Stars
• 2) Brittle Stars
• 3) Sea Urchins
• 4) Sea Cucumbers

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Chapter Review

• Test Format
• MC and T/F
• Short Answer and Essay
• Diagrams
• Characteristics of Arthropods (pg. 49)
• Sea Star (pg. 71)
• Essay (choose one!)
• 1) Describe the stages of complete metamorphosis.
• 2) Name the three body sections of insects, and
  tell which organs and appendages are found on or
  in each section.

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