Athropods

Question 1

What is arthropoda

Answer 1

A phylum found within the superphylum Ecdysozoa

Question 2

Panarthropoda additionally encompass..?

Answer 2

Tardigrada and Onychopohora

Question 3

How many species of water bears are there

And what conditions can they survive in

Answer 3

1250
Water-dwellers, found nearly everywhere
Can survive, extreme temp, pressure, space vacuum, radiation, lack of water.- cryptobiosis

Question 4

What are onychopohora

Answer 4

Velvet worms

Question 5

How many species of onychophora are there

Answer 5

200
Convergent similarities to annelids
Shoot slime from appendages on the head
Most give birth to live young viviparous

Question 6

What are the four extant subphyla that arthropods can be split into

Answer 6

Hexapoda
Crustacea
Myriapoda
Chelicerata

Question 7

Hexapods include what?

Answer 7

Winged insects and other wingless arthropod groups

Question 8

What are the major orders of insects?

Answer 8

Beetles, butterflies and moths, ants, wasps and bees, flies

Could be 30 million species of insects in total
Some undergo metamorphosis

Question 9

What do crustacea include

Answer 9

Lobsters, crabs, crayfish, shrimp, krill, barnacles, and woodlice
Mainly marine, some fresh water and terrestrial
Key trophic link in marine ecosystems between primary producers and higher level consumers
Huge morphological diversity

Question 10

What do myriapods include

Answer 10

Centipedes and millipedes

Centipedes always have odd number of leg pairs, poison fanged nocturnal active hunters

Millipedes eat rotting gveg and wood, secret noxious chemicals as a defence mechanism

Question 11

What are chelicerata

Answer 11

Ticks and mites, scorpions, and spiders

Called chelicerata due to chelicerae appendages (pincers)

Important pests, parasites, and predators

Independent invasion and radiation in dry land habitats compared to insects

Question 12

What are trilobites

Answer 12

Extinct subphylum - existed for 300 million years.

Abundant, widely distributed in the sea
had 10 orders and over 17000 species
Fossils date back to 520mya

Extinction due to competition with crustaceans, and predation pressure from early fish

Question 13

Crustacea are …?

Answer 13

Paraphyletic

Question 14

Hexapods have evolved from who?

Answer 14

Crustacean ancestor

Question 15

Placement of myriapods are..?

Answer 15

Not resolved

Question 16

How many years ago did arthropods emerge

Answer 16

540mya

Question 17

What are the defining features of arthropods

Answer 17

They have segmentation, joined appendages, and exoskeleton

Question 18

What is segmentation

Answer 18

The common ancestor of all arthropods had a series of similar segments - homonomous

Segments in extant derived taxa are often fused/lost, specialised.. heteronomous

Segmentation is still apparent during embryonic development

Question 19

What is tagmosis

Tagmosis was independent between insects, crustaceans+ chelicerates

Answer 19

The grouping of segments with similar functions/structures
All arthropod grouped segments to form a head - specialised region for feeding, sensing, and neural integration
Most divide the rest of the body into a thorax and abdomen
Chelicerates fused head with thorax region to form a cephalothorax

Question 20

Segmentation:appendages

Answer 20

Ancestor had appendage on each segment
Arthropods have evolved a wide range f specialised paired appendages
Appendages themselves are segmented - called articles
Appendages on head specialised for feeding and sensing

Others for locomotion, reproduction, respiration, food manipulation etc…

Question 21

Jointed appendages

Answer 21

Joints allow articulation between appendage articles despite hard exoskeleton

Flexible cuticle at the joint that allows bending

Antagonistic muscles control joint movement

Flexor and extensor muscles allow movement of articles relative to each other
Protractor and retractor muscles allow appendage extension/retraction

Question 22

What does the cuticle do

Answer 22

Provides support, maintains shape, joint articulation, protection against pathogens and mechanical forces

Made from chitin
Properties range from hard carapace shells to stretchy tendons

Controlled by sclerotisation - where tanning leads to cross-linking and stronger propoerties

Question 23

Moulting

Answer 23

Takes place to permit growth. Ecdysis - cuticle periodically moulted to permit growth

Pre moult, moult, post moult, inter moult

Intermoult period can only be 10% of the arhtropod’s life

Question 24

Arthropods are major vectors for what

Answer 24

Disease. 700million people a year get a mosquito borne illness

Vectors include ticks, fleas, lice, bugs and other flies

Question 25

What are parasitic form of arthropoda

Answer 25

Ticks, mites, flies, fleas, lice and various crustaceans inc. tongue worms and copepods

Mainly ectoparasites some are endoparasites

Some wasps and flies are parasitoids

Question 26

What useful tasks arthropods do for humans

Answer 26

Pollination of crops, recycling, pest control

Question 27

Inspiration?

Answer 27

Drone design, skills and chitins provide inspiration for innovative oil free materials