Chapter 10

1. Chapter 10 Mollusks, Arthropods, and Echinoderms 7th Grade Science

2. Mollusks • __________ - invertebrates with soft unsegmented bodies that are often protected by a harder outer shell • _________ - a thin layer of tissue that covers the internal organs – produces the hard shell • _______ - crawling, digging, or catching prey • Examples of Mollusks – clams, snails, scallops, oysters Mollusks Mantle foot

3. Characteristics of Mollusks • _____________ - bilateral symmetry and a digestive system with __________. Body parts are not repeated as in segmented worms – instead organs are located in one area. • _________________ - blood is not always inside blood vessels – blood sloshes over the organs and returns to the heart. Body Structure Two openings Open circulatory system

4. Obtaining oxygen • ____ - mollusks that live in water obtain oxygen through _______ and __________ • _____ - hair-like structures that move back and forth making the water flow over the gills • Gills remove oxygen from the water and passes it into the bloodstream • Wastes are also removed through the ______ into the water gills cilia Blood vessels cilia gills

5. Three Main Groups • Mollusks are classified into three main groups based on _______________ • Three main groups of mollusks are: • ___________ - single external shell or no shell • __________ - two shells held together by hinges • ___________ - ocean dwelling – foot adapted to form tentacles around its mouth Physical characteristics gastropods bivalves cephalopods

6. Gastropods • ___________of mollusks • Examples: _____________ • Live nearly everywhere on earth • Some are ________, _________, and ________ • ________ - organ that is a flexible ribbon of tiny teeth to obtain food • Movement – creeping along on a broad _____ Largest group Snails and slugs herbivores carnivores scavengers radula foot

7. Bivalves • Oysters, clams, scallops, and mussels • Found in ________________ • ____________ - strain their food out of water as it flows over their gills • __________ • Movement - _____ float or swim, adults attach themselves to hard surfaces or use their ____ to move slowly Water environments Filter feeders omnivores larva foot

8. Cephalopods • Octopuses, squids, cuttlefish • Only mollusks with a __________________ • _________ - captures prey using muscular tentacles. • ________ - uses to cut the flesh of its prey • ___________ - most complex of all invertebrates, large eyes and excellent vision, large brains and ability to remember learned items. • Movement - ____________ Closed circulatory system carnivores radula Nervous system Jet propulsion

9. Arthropods • ___________ - spider, grasshopper, crabs, lobsters, centipedes and scorpions. • Classified into 4 major groups: • __________ • __________ • ___________________ • ____________ arthropods crustaceans arachnids Centipedes and millipedes insects

10. Arthropods Body Structure • Arthropods are __________ that have: • _______________ • _______________ • ___________ - jointed attachments “arthros” – Greek for ______ “podos” – Greek for __________ • Bilateral symmetry • ______ circulatory system and a digestive system with ___________ • Reproduce sexually invertebrates External skeleton A segmented body Appendages joint Foot or leg open Two openings

11. Outer Skeleton • ___________ - waterproof outer covering • Exoskeleton _________ the animal and prevents __________ • Arthropods occasionally shed their exoskeleton and grow new ones that are larger. • __________ - the process of shedding the exoskeleton exoskeleton protects Evaporation molting

12. Segmented Body • Segmented bodies similar to an earthworm • Easy to see segments in _________ and __________. • An arthropod may have up to three segments: • _________ • _________ • ___________ Segments are _________ looking centipedes millipedes head Mid-section Hind section identical

13. Jointed Appendages • ________ in ___________ give the animal ____________ and enable it to ________ • ______________________ tools for moving, eating, reproducing, and sensing the environment • ________ - an appendage that is attached to the _____ that contains sense organs. • ____ and _____ are also appendages Joints appendages flexibility move Appendages are highly specialized antenna head legs wings

14. Diversity • Scientists have identified more species of arthropods – over a million – than all other species of animals combined!

15. Crustaceans • ___________ - shrimp, crab, and pill bugs • Crustaceans thrive in ________, ______, or ___________ • ___________ - two or three body sections, five or more pairs of legs, and two pairs of antenna • ______ - most have gills to obtain oxygen • ____ - scavengers, predators, herbivores crustaceans freshwater oceans Damp places Body structure oxygen food

16. Life Cycle of Crustaceans • Life cycle for many varieties begins as _______ • ______________ - a process in which an animal’s body undergoes dramatic changes in form during its life cycle. • _________ develop into adults through ____________. larvae metamorphosis larvae metamorphosis

17. Arachnids • ________ - spiders, mites, ticks, and scorpions • Arachnids are _________ with two body sections, four pairs of legs, and no antennae • ____________ - combined head and midsection • _____________ - hind section called the ________ • ___________ - contains the reproductive organs and part of the digestive system. arachnids arthropods First body section Second body section abdomen abdomen

18. Spiders / Mites/ Scorpions/Ticks • All spiders are ________ and most eat _______. • Adaptations include _____ - used to inject venom and sucks in food • _______ and chiggers are _________ • __________ - adaptation is a _____ at the end of its abdomen to inject venom into prey. • ______ - parasites that live on the outside of hosts bodies predators insects fangs parasites Mites stinger scorpions ticks

19. Math / Analyzing Data pg. 341

20. Centipedes and Millipedes • Centipedes and millipedes are _________ with ____________ and _____________. • First body section has a _____ with one pair of _________ • The second body section has a long _________ with many body segments • ___________ have one pair of legs attached to each segment arthropods Two body sections Many pairs of legs head antennae abdomen centipedes

21. Centipedes and Millipedes Continued • Centipede means ______________ • Centipedes are very fast _______ that inject venom into their ____. • ____________ - have more than 80 segments have _____ pairs of legs on each segment. • Millipede means _____________ - they do not have that many • Millipedes are _________ “ one hundred feet” predators prey Millipedes two “thousand feet” scavengers

22. Section 2 Assessment • Page 342 (1 and 2)

23. Insects • ________ - caterpillars, plant hoppers, dragonflies, and bees • Insects are ___________ with all of the following: • _________________ • ________ • _________________ • ________________ insects arthropods Three body sections Six legs One pair of antennae Two pairs of wings

24. Body Structure • The three body sections are: • ________ - most of the insects sense organs, two large compound eyes – keen at sensing movement. Simple eyes distinguish between light and darkness. • _______ - midsection where wings and legs are attached. Insects are the only invertebrates that can fly • _________ - contain the internal organs head thorax abdomen

25. Obtaining food • Insects feed on all of the following depending on their specialized and adapted _________: • _________________________ • __________________________________ • ______________________________________ • _________________________ • ______________________________________ mouthparts Parts of plants – leaves or nectar Products that are made from plants – book lice Animal – fleas and mosquitoes feed on the blood of living animals Animal droppings – dung beetle Decaying bodies of dead animals – burying beetles

26. Life Cycle • Insects are born from tiny, hard shelled ___________ • After they hatch, insects begin a process of ____________ (either complete or gradual) before becoming an _____insect. • __________________ - four stages • _______ • ______ - specialized for eating and growing • ______ - enclosed in a protective covering • _______ - beetles, butterflies, flies and ants Fertilized eggs metamorphosis adult Complete metamorphosis egg larvae pupa adult

27. Gradual Metamorphosis • ________________ - no distinct larval phase. • Egg hatches into a stage called a _____ • _________ - looks like an adult insect without wings • Grasshoppers, termites, cockroaches and dragonflies. Gradual metamorphosis nymph nymph

28. Insect Ecology • ___________ - series of events in which one organism eats another and obtains energy. • __________ - the study of food chains and other ways that organisms interact with their environment • All food chains begin with the ____ • Next a _________ - an organism that makes its own food – grass and other plants. Food Chain ecology sun producer

29. Insects and the Food Chain • ___________ - producers are the food that provides energy. Some consumers also eat other _________. • ___________ - breaks down the wastes and dead bodies of other organisms • Insects can either be _________ or _________ in the food chain • Insects can be ______ for other consumers consumers consumers decomposers consumers decomposers prey

30. Insects as Consumers, Prey, and Decomposers • Insects eat about ____ of the crops grown by humans as well as wild plants. • Caterpillars ________ plant materials • Caterpillars and other insects are _______ for other types of animals such as birds and fish. • Insects such as the carrion beetle are __________ - feed on the tissues of dead birds. 20% consume prey decomposers

31. Pollen and Disease Carriers • _________ - an animal that carries pollen among plants. Examples of insects as pollinators are _______________. • Without pollinators some plants would not be able to _________ • Insects that carry diseases often have ______________ that pierce the skin of their prey that provides an opening for the disease to enter the organisms body - ______ pollinators Bees, beetles, and flies reproduce Sucking mouth parts malaria

32. Controlling Pests • _________ - use of chemicals to control pests • Pesticides have also killed _________ • Humans have also used ____ and other __________ (such as other insects) to control pests. • _______________ - a natural predator or disease released into an are to fight a harmful insect. pesticides pollinators traps Living things Biological control

33. Echinoderms • _____________ - invertebrates with an internal skeleton and a system of fluid filled tubes. • All echinoderms live in ________ • The internal skeleton of the echinoderms is called an __________ - made up of hard plates which give the animal a bumpy texture. • ______________ usually in multiples of 5 Echinoderms Salt water Endoskeleton Radialy symmetrical

34. Movement • _________________ - the internal system of fluid-filled tubes • The water vascular system contracts and forces water into the _______ - the ends of the tube feet are sticky and they act like suction cups. • The ________ and __________ allow the echinoderms to grip the surface beneath them Water vascular system Tube feet suction stickiness

35. Reproduction and Life Cycle • _____ are usually fertilized in the ______ • Fertilized egg develops into a swimming ______ . • ______ undergo ___________ and become ______ echinoderms. • 4 major groups of echinoderms: __________, __________, _________, __________ eggs water larvae larvae metamorphosis adult Sea stars Brittle Stars Sea Urchins Sea Cucumbers