Arthropoda

Question 1

Describe arthropods

Answer 1

Jointed appendages, segmented body, highly cephalised, undergo ecdysis

Question 2

What are the three arthropod subphyla?

Answer 2

Chelicerates, myriapods, pancrustacea

Question 3

Arthropods were

Answer 3

The first animals to colonise land

Question 4

Describe trilobites

Answer 4

Mostly benthic scavengers. Extinct at P-T

Question 5

What phyla contains arachnids?

Answer 5

Chelicerates

Question 6

Describe chelicerates

Answer 6

Most liquid prey before consuming

Question 7

Name six orders of Arthropods

Answer 7

Aranae, Opiliones, Solifugae, Scorpiones, Thelyphonia, Acari

Question 8

Describe the order Aranae

Answer 8

Chelicerates, obligate carnivores, produce silk, sensations on hairs, hunting by webs, fish, trapdoors

Question 9

Describe the order Opiliones

Answer 9

Single fused body segment, long legs, masticate food (not liquidate)

Question 10

Describe the order Solifugae

Answer 10

Small and predatory arachnids, live in arid environment. Sun spiders.

Question 11

Describe the order Scorpiones

Answer 11

Tropical generalised predators. Ambush to lose less energy

Question 12

Describe the order Thelyphonia

Answer 12

Whip scorpions (similar pedipalps to scorpions)

Question 13

Describe the order Acari

Answer 13

Mites and ticks. Can be terrestrial and marine. Can be pathogenetic/vectors

Question 14

What classes are in Mandibulata?

Answer 14

Myriapoda and Pancrustacea (all crustaceans and hexapods (insects and relatives)

Question 15

What is the ancestral condition of mandibulate?

Answer 15

Mandibles (found in Rhynie Chert, 400mya)

Question 16

Name the two classes in the Myriapoda subphylum

Answer 16

Diplopoda (millipedes) and Chilopoda (centipedes)

Question 17

Describe Diplopoda

Answer 17

2 leg pairs per segment, first animals to terrestrialise (Cambrian), detrivores, calcitic exoskeleton

Question 18

Describe Chilopoda

Answer 18

1 leg pairs per segment, predatory

Question 19

What are insects?

Answer 19

Highly derived crustaceans

Question 20

Describe a synapomorphy of Pancrustacea

Answer 20

2 pairs of antennae

Question 21

Name Pancrustacea classes

Answer 21

Isopoda and Decapoda

Question 22

Describe the class Isopoda

Answer 22

Woodlice and relatives, no carapace, dorsally flattened

Question 23

Describe the class Decapoda

Answer 23

Includes crabs and lobsters (more primitive), nocturnal, 5 pairs of walking legs,

Question 24

Name 3 orders in the subphylum Hexapoda

Answer 24

Protura, Diplura, Colembola

Question 25

Describe the class Insecta

Answer 25

3 leg pairs, 2 antennae pairs, paired cerci on end segment (like on back of silverfish), Johnson’s organ (synapomorphy used to detect sound)

Question 26

Describe possible reasons for the success of class Insects (with success as species richness)

Answer 26

High speciation rate, low extinction rate, labile segmented body, neopterous wings, herbivory (coevolve with plants), larval stage

Question 27

Describe Hemimetabolous

Answer 27

Gradual growth after nymph stage, no pupal stage, wings grow outside, can have radical change,

Question 28

Describe Holometabolous

Answer 28

Full metamorphosis after larval stage, wings grow inside

Question 29

Why is there no difference in the speciation rates and extinction rates of hemimetabolous and holometabolous species?

Answer 29

Exploiting different plants, expand into empty terrestrial niches and are then difficult to dislodge

Question 30

What are the two categories of the class Insecta?

Answer 30

Apterygota (wingless) and Pterygota (winged)