Arthropod I

Question 1

What is Arthropoda and what is it within?

Answer 1

Superphylum - Ecdysozoa

Phylum - Arthropoda

Question 2

What does Ecdysozoa include?

Answer 2

Arthropoda
Onychophora
Tardigrada

Question 3

What are the 5 subphyla (extinct and extanct) of Arthropoda

Answer 3

Extanct:
Crustacean 
Hexapodes 
Chelicerata 
Myriapoda 

Extinct:
Trilobite

Question 4

Three characterisations of Arthropoda

Answer 4

Segmentation
Jointed appendages
Exoskeleton

Question 5

Homonomous meaning

Example

Answer 5

Parts having a similar forms and structure and arranged in a series (eg. Fingers or toes)

Eg. Common ancestor of all Arthropoda had a series of similar segments

Question 6

Heteronomous meaning

Example

Answer 6

Parts of an organisms differing in manner of growth, development or specialisation

Eg. Segments in extanct taxa differ as they are are fused/lost/specialised

Question 7

Tagmosis

Answer 7

Grouping of segments with similar function/structure

Question 8

Main three Arthropod tagmata

Answer 8

Head
Thorax
Abdomen

Question 9

X

Answer 9

Trunk

Question 10

Cephalothorax

Answer 10

X

Question 11

X

Answer 11

Appendages on each segment

Question 12

Article

Answer 12

Segments on appendages themselves

Question 13

What do arthropod joints allow?

Answer 13

Appendage articles can be articulated despite the hard exoskeleton

Question 14

What is at an arthropod joint?

Answer 14

Flexible cuticle allows bending

Question 15

What controls arthropod appendage movement?

Answer 15

Antagonistic muscles

• flexor and extensor muscles allow movement of articles relative to each other
• protractor and retractor muscles allow appendage extension and retraction

Question 16

What does the cuticle/exoskeleton provide?

Answer 16

Support
Maintains shape
Allows joint articulation
Provides protection against pathogens

Question 17

What is arthropod cuticle made of?

Answer 17

Chitin (polysaccharide)

Question 18

Sclerotisation

Answer 18

Biochemical process where protein chains that make up the cuticle are molecularly stabilised due to the establishment of cross chains

Question 19

Sclerotin

Answer 19

Component of the cuticle formed by sclerotisation

Darker areas are more rigid

Question 20

Ecdysis

Answer 20

Process of casting off old outer cuticle

Question 21

Stages of moulting

Answer 21

Pre moult - detach old cuticle and develop new cuticle
Moult - shed old cuticle
Post moult - harden new cuticle
Intermoult - only roughly 10% of Arthropoda life

Question 22

What is arthropod mortality linked to?

Answer 22

80-90% arthropod mortality is linked to moulting

Question 23

Where is the poison claw?

Answer 23

On a centipede’s 1st trunk segment

Question 24

Characteristics of myriapods

Answer 24

Head
Trunk
Single antennae
Open trachea

Question 25

Diplosegments

Answer 25

Occur on millipedes which have two legs on each segment

Question 26

Where are the modified anal legs of centipedes?

Answer 26

Last trunk segment

Question 27

What are the 5 major subgroups of chelicerata?

Answer 27

Aranae (spiders)
Scorpiones 
Acari (mites and ticks)
Xiphosura (horse shoe crabs)
Pycnogonida (sea spider)

Question 28

What two body segments do chelicerates have?

+ two other characteristics

Answer 28

Cephalothorax
Abdomen

Chelicerae
Compound eyes

Question 29

What type of lungs do arachnids have?

Answer 29

Book lungs

Question 30

Silk use in spiders (4)

Answer 30

Feeding
Reproduction
Locomotion and dispersal
Sensing