Ch 28 Outline: Arthropods

1. Ch 28 Outline: Arthropods

2. What animals are in the phylum Arthropods? • Bumble bees • Spiders • Octopus • Lobsters • Millepedes Answer all that apply by holding up more than one card. Answer: A, B, D, E

3. There are 4 Subphyla of Arthropods • List the three subphyla that are still living. If you can’t remember the names of the subphyla, write down the representative species that are in each group. Answer: chelicerates, crustaceans, uniraminans

4. Which subphyla representatives are are matched to the proper names? • A. uniramians – prawns • B. chelicerates – spiders • C. crustaceans – cockroaches • D. triobites – millepedes

5. 4 Subphyla: • Trilobites (now extinct) • Chelicerates – spiders, ticks, mites, scorpions, horseshoe crabs • Crustaceans – crabs, shrimp, lobster • Uniramians – centipedes, bees, moths, grasshoppers, flies, bettles

6. Evolution: Which insects have common ancestors with modern annelids (segmented worms) • A. insects • B. Centipedes • C. millipedes • D. crustaceans • E. spiders (chelicerates) • (hold up multiple letters if more than one answer apply) Answer: A, B, C

7. Evolution • Insects, centipedes and millipedes seem to have common ancestors with modern annelids • Crustaceans and spiders evolved from different ancestors

8. What is special about the Velvet worm? • A. it is a living fossil • B. it is extinct, but has the characteristics of arthropods • C. It seems to be a “transition” organism between the annelids and the arthropods • D. It has larvae that are the same as insect larvae • E. It makes a substance that resembles velvet Answer: C

9. The Velvet worm • Placed in its own phylum (along with others like it) • Has characteristics of both annelids and arthropods

10. The First Arthropods?

11. What Evolutionary trends are shown within the Arthropods? • A. early arthropods have a sac body plan; later arthropods have tube-within-a-tube • B. early arthropods have bilateral symmetry; later arthropods have radial symmetry • C. early arthropods have many smaller body segments; later arthropods have fewer but larger body segments • D. early arthropods do not fly; later arthropods do • E. early arthropods have many unspecialized appendages, later arthropods have fewer, more specialized appendages Answer: C and E

12. Arthropod Evolutionary Trends • Far fewer body segments (segments in embryo fuse into larger ones) • Appendages become more and more specialized

13. What are the names of the three main body segments of an insect? • A. head, legs, wings • B. appendages, thorax, exoskeleton • C. head, thorax, abdomen • D. anterior, posterior, ventral • E. dorsal, ventral, posterior Answer: c

14. Structure – head, thorax and abdomen

15. List at least two characteristics that unify the phylum Arthropoda. • (Answer on next slide)

16. Arthropods – Characteristics that Unify • Jointed appendages– antennae,claws, legs, wings,flippers, etc. • Exoskeleton • Segmented body • Open circulatory systems

17. What is the main molecule in exoskeletons, and what type of molecule is it? • A. cellulose, a complex carbohydrate • B. glucose, a simple carbohydrate • C. chitin, a complex carbohydrate • D. starch a complex carbohydrate • E. glycogen, a complex carbohydrate Answer: C

18. What is a major DISADVANTAGE to having an exoskeleton rather than an endoskeleton? • A. it is not as strong as an endoskeleton • B. it cannot heal like an endoskeleton can (if it breaks) • C. it is more vulnerable to breaking since it is on the outside of the body • D. it does not grow larger like an endoskeleton can • E. it is not as flexible as an endoskeleton is. Answer: D

19. Exoskeletons • Made of chitin • Some leathery/flexible • Some waterproof • Must be molted for the animal to grow

20. There are 4 different structures that insects use to breathe. List at least 2 of them • (Answer on next slide)

21. Respiration • Arthropods have 4 basic structures for respiration: • Gills, Book Gills, book lungs and Tracheal tubes

22. Respiration - Arthropods • Aquatic arthropods (crabs and shrimp): GILLS

23. Book Gills • Unique to horseshoe crabs • Tissues are layered

24. Book Lungs – Layered Tissues • Unique to Chelicerates  Book lungs

25. How does the air come into the insect if it is “Breathing” using tracheal tubes? • A. the air moves through the tubes when the muscles move the abdominal cavity • B. there is an area inside the expands and contracts like our diaphragm – this draws the air in • C. they have an incurrent siphon that pulls the air through • D. they use their wings to “fan” the air in Answer: A

26. What are “spiracles”? • A. the sensory receptors on the ends of antennae • B. The structures that are used for hearing for insects • C. the structures that are used to spin webs in spiders • D. the holes that allow air into the tracheal tubes • E. the barbs on the sides of some insects legs for extra traction. Answer: D

27. Tracheal Tubes • Branching tubes throughout the tissues • Shrink and contract when insect’s muscles move • Causes air to pump in and out of tissues • Attached to spiracles (holes on outside of body)

28. Tracheal Tubes

29. Feeding

30. What can insects eat? • A. plants • B. animals • C. rotting organic matter • D. fungi (mushrooms) • E. bacteria Answer: ALL of the above!

31. Modified appendages enable different arthropods to eat almost anything

34. The Difference (s) between an open and closed circulatory system is (are): • Closed systems have a heart (pump); open systems do not. • Closed systems have blood vessels; open systems do not. • Closed systems do not have sinuses (pools of blood for nutrient exchange); open systems do. • Closed systems are more efficient at nutrient and gas exchange; open systems are less efficient. • Humans have closed circulatory systems; arthropods have open systems Answer: C, D , E

35. Internal Transport • OPEN circulatory system with a well-developed heart (limits their size!!) • Heart pumps blood through blood vessels to sinuses where gas and nutrient exchange occurs with the tissue • Blood re-collects in large cavity surrounding heart and then enters heart to be pumped again

36. Open vs. Closed Circulatory Systems

37. Open vs Closed Circulatory Systems

38. How do Arthropods get rid of their SOLID wastes? • A. the solid waste exits back through their mouths • B. The solid wastes exit through their anus • C. The solid wastes exit through their spiracles • D. The solid wastes exit through their Malpigian tubules • E. The solid wastes exit through their sinuses Answer: B

39. How do Arthropods get rid of their nitrogenous wastes? • A. the N2 wastes are concentrated by their Malpigian tubules • B. the N2 wastes are excreted through their anus • C. the N2 wastes are excreted through their spiracles • D. The N2 wastes are concentrated by their tracheal tubes • E. The N2 wastes are excreted through their gills Answer: A, B, E

40. Excretion • Solid waste exits through anus • Insects and spiders remove nitrogenous wastes with Malpighian tubules that are in the blood sinuses • Nitrogenous wastes are concentrated by tubules and added to solid waste for excretion.

41. Where (in their bodies) do Arthropods have structures to get rid of nitrogenous waste structures? • A. their head • B. their abdomen • C. the base of their legs • D. their tracheal tubes • E. the ends of their antennae Answer: A, B, C

42. Some terrestrial arthropods may also have excretory glands on base of legs. • Some arthropod have these glands instead of Malpighian tubules

43. Aquatic Arthropod Excretion • Excrete metabolic wastes through gills. • Lobsters also have a pair of green glands on their head that eliminate nitrogenous wastes! (green gland)

44. How are Arthropods’ nervous systems different than humans? • A. We have a brain, they only have ganglia • B. Our brain controls all our body except for reflexes; their brain controls some but not all of their functions • C. We have a nerve cord; they do not have a nerve cord • D. our nerve cord is on our dorsal surface; theirs is on their ventral surface • E. Our NS is higher functioning on all levels than their nervous systems Answer: B, & D

45. Response –well developed NS Have brains in head that act as main coordinator, and ganglia in each segment that coordinate movement in that segment. • Brain and ganglia are connected by a ventral nerve cord

47. How do compound eyes differ from Human eyes? • Compound eyes do not have the ability to focus an image as well as our eyes can • Compound eyes do not see color • Compound eyes can focus much better than our eyes because they have SO many lenses to work with. Our eyes only have one lens. • Compound eyes see motion much better than our eyes can. • Compound eyes produce larger images than our eyes Answer: A, D

48. Sense organs • Have simple organs – statocysts and chemoreceptors • Most also have more complicated organs • Compound eyes are common • > 2000 separate lenses – excellent at detecting colour and movement (better that we can!) • Most can detect UV light

50. Where do Arthropods have taste buds? • Tongue • Mouth parts • Legs • Abdomen • antennae Answer: B, C, E