Topic 1: Phylum Arthropoda

Question 1

ARTHROPODS

Answer 1

1. segmented body and appendages
2. characterized by external skeleton

Question 2

TAGMATIZATION

Answer 2

1. fusing of individual segments found in arthropods

Question 3

DISTINCT CHARACTERISTICS OF ARTHROPODS

Answer 3

1. segmented body
2. well-developed sensory organs
3. flexible chitinous exoskeleton
4. open circulatory system
5. sexual dimorphism

Question 4

CLASSIFICATION OF ARTHROPODS (SUBPHYLA)

Answer 4

1. hexapoda
2. chelicerata
3. crustacea
4. trilobitomorpha
5. myriapoda

Question 5

TRILOBITOMORPHA

Answer 5

1. all extinct (preserved fossils)
2. marine animals
3. disappeared in the Permian-Triassic extinction

Question 6

CRUSTACEA

Answer 6

1. terrestrial; fresh water; marine animals
2. divided into 6 classes
3. body region: 2 (cephalothorax, abdomen)
4. legs: 5-7 pairs
5. eyes: 1 pair (compound)
6. antennae: 2 pairs
7. miscellaneous structures: swimmerets; gills
8. lobsters; crabs; shrimps

Question 7

MYRIAPODA

Answer 7

1. terrestrial; air breathing arthropods
2. divided into 4 groups
3. body region: 2 (head, body)
4. legs: 1-2 pairs per body segment
5. eyes: 1 pair (compound)
6. antennae: 1 pair
7. miscellaneous structures: flat body
8. millipedes; centipedes; pauropus

Question 8

CHELICERATA

Answer 8

1. divided into 2 classes
2. body region: 2 (cephalothorax, abdomen)
3. legs: 4 pairs
4. eyes: 3-4 pairs (simple)
5. antennae: 0
6. miscellaneous structures: spinnerets (silk)
7. scorpions; mites; spiders

Question 9

ARACHNIDS

Answer 9

1. two body regions
2. cephalothorax: 6 pairs of appendages (chelicera, pedipalp, 4 pairs of walking legs)
3. abdomen: 3 pairs of appendages (spinnerets)

Question 10

SPIDERS

Answer 10

1. cephalothorax (prosoma)
2. abdomen (opisthosoma)
3. presence of pedicel (separates cephalothorax and abdomen)

Question 11

MITES

Answer 11

1. head (gnathosoma)
2. abdomen (idiosoma)
3. reduced segmentation
4. body appears to be without divisions

Question 12

HEXAPODA

Answer 12

1. terrestrial; aquatic arthropods
2. body region: 3 (head, thorax, abdomen)
3. legs: 3 pairs
4. eyes: 1 pair (compound, 0-3 (simple)
5. antennae: 2
6. miscellaneous structures: wings; few can produce silk