Chapter 33: Invertebrates Flashcards Preview

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Flashcards in Chapter 33: Invertebrates Deck (30)
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1

Introduction

  • Animals that lack backbone are called invertebrates
  • account for 95% of animal species

2

Sponges

  • Belong to Phylum Porifera
  • Lack true tissues, organs
  • Suspension feeders
  • Hermaphrodites – Male/Female

3

​Cnidarians

  • Belong to Phylum Cnidaria
  • Clade Eumetazoa - True tissue
  • Diploblastic, radial symmetry
  • Two body plan
    • 1. Polyp
    • 2. Medusa

4

2 Major Clades of Cnidarians

  • 1. Medusozoa
    • members produce a medusa
  • 2. Anthozoa
    • members only occur in polyps 

5

Medusozoans

  • Has 3 Groups:
    1. Scyphozoans - true jellyfish
    2. Cubazoans -  box jellies
    3. Hydrozoans - Hydra, Obelia

6

Anthozoans

  • Include sea anemones, corals
  • hard exoskeleton of calcium carbonate

7

Lophotrochozoa

  • Clade characterized by
    • 1.  Lophophore
    • 2. Trochophore larva
  • Has six major phyla *

8

Flatworms

  • Belong to Phylum Platyhelminthes
  • Include:
    • 1. Planarians
    • 2. Trematodes - flukes
    • 3. Tapeworms

9

Rotifers

  • Belong to Phylum Rotifera
  • Reproduce by parthenogenesis
    • offspring from unfertilized eggs
  • Some species lack males entirely 

10

Lophophorates

  • Have crown of ciliated tentacles around mouth
  • Used in suspension feeding
  • Include phyla:
    • 1. Ectoprocta - “moss animals”
    • 2. Brachiopoda - “lamp shells”

11

Molluscs

  • Belong to Phylum Mollusca
  • 2nd largest animal phlya
  • Most have shell
  • Body w/ 3 main parts
    • 1. Foot
    • 2. Visceral mass
    • 3. Mantle

12

Molluscs cont...

  • Include clades
    • 1. Polyplacophora - chitons
    • 2. Gastropoda
    • 3. Bivalvia
    • 4. Cephalopoda

13

Chitons

  • shell of eight dorsal plates

14

Gastropods

  • Most have singled, spiral shell

15

Bivalves

  • Shells in two halves, hinged

16

Cephalopods

  • Have well developed sense organs, brains

17

Annelids

  • Belong to Phylum Annelida
  • Are segmented worms
  • Groups include
    • 1. Leeches
    • 2. Earthworms

18

Ecdysozoans

  • Clade characterized by shedding of cuticle
  • Process called ecdysis (molting)
  • Two major phyla
    • 1. Nematoda
    • 2. Arthropoda

19

Nematodes

  • belong to Phylum Nematoda
  • called roundworms; many parasitic members

20

​Arthropods

  • Belong to Phylum Arthropoda
  • Probably 1 billion + species
  • Body characteristics
    • 1. Segmented body
    • 2. Hard exoskeleton
    • 3. Jointed appendages

21

Arthropod Anatomy

22

Arthropods cont...

  • Three major lineages
    • 1. Chelicerates
    • 2. Myriapods
    • 3. Pancrustaceans

23

Chelicerates

  • Include spiders, scorpions, ticks, mites, horse crabs
  • Named after feeding appendages (chelicerae)
    • serve as pincers or fangs
  • Head lacks antennae

24

Arachnids (group of chelicerates)

  • Bulk of chelicerates
  • Six pair of appendages
  • Spiders: construct silk webs

25

Myriapods

  • Include
    • 1. Centipedes
      • carnivores
      • poisonous claws
    • 2. Millipedes
      • feed on plant matter

26

Pancrustaceans

  • Newly formed clade
  • Two groups
    • 1. Crustaceans
    • 2. Hexapods - insects

27

Crustaceans (pancrustaceans)

  • Include crabs, lobsters, shrimp, barnacles
  • Two pair of antennae 

28

Hexapods (pancrustaceans)

  • Over 900,000 species
  • Head, thorax, abdomen
  • Six legged - 3 pair
  • 1 or 2 pairs of wings
  • Undergo metamorphosis

29

Deuterostomia

  • Shares embryological characteristics
  • Though primarily grouped by DNA 
  • Two major groups
    • 1. Echinoderms
    • 2. Chordates

30

Echinoderms

  • Belong to Phylum Echinodermata
  • Slow moving, sessile
  • Display radial symmetry as adults
  • Include sea stars, sea urchins