Arthropods

Question 1

What superphylum are arthropods part of

Answer 1

Ecdysozoa.

Question 2

What organisms are in Panarthropoda

Answer 2

Arthropods, tardigrades, and onychophorans.

Question 3

What % of all known animal species are arthropods

Answer 3

Around 80%.

Question 4

What are the 4 living subphyla of Arthropoda

Answer 4

Hexapoda, Myriapoda, Crustacea, Chelicerata.

Question 5

What is the main evolutionary origin of hexapods

Answer 5

They evolved from a crustacean ancestor.

Question 6

Which arthropods independently invaded land

Answer 6

Chelicerates and hexapods.

Question 7

What is tagmosis

Answer 7

The fusion of body segments into functional units.

Question 8

What’s the difference between homonomous and heteronomous segmentation

Answer 8

Homonomous = similar segments; Heteronomous = specialized segments.

Question 9

What is the cephalothorax

Answer 9

Fused head and thorax found in chelicerates.

Question 10

What are the three tagmata in insects

Answer 10

Head, thorax, abdomen.

Question 11

What is an article in arthropods

Answer 11

A segment of an appendage.

Question 12

What are the four types of limb movement muscles

Answer 12

Flexor, extensor, protractor, retractor.

Question 13

How do spider legs work

Answer 13

One direction uses hydrostatic pressure, the other uses muscles.

Question 14

What are uniramous vs biramous appendages

Answer 14

Uniramous = single branch; Biramous = two branches.

Question 15

What is sclerotisation

Answer 15

A hardening (tanning) process of the cuticle.

Question 16

What is ecdysis

Answer 16

The moulting process arthropods use to grow.

Question 17

What are the stages of the moulting cycle

Answer 17

Pre-moult, moult, post-moult, inter-moult.

Question 18

What is the arthropod exoskeleton made of

Answer 18

Chitin.

Question 19

What is ametabolous development

Answer 19

No metamorphosis; juveniles resemble adults.

Question 20

What is hemimetabolous development

Answer 20

Incomplete metamorphosis; nymphs resemble adults but lack wings/genitalia.

Question 21

What is holometabolous development

Answer 21

Complete metamorphosis with distinct larval, pupal, and adult stages.

Question 22

What is an imaginal disc

Answer 22

A group of embryonic cells in holometabolous insects that forms adult structures.

Question 23

What are some benefits of holometaboly

Answer 23

Reduced competition between life stages; high adaptability and specialization.

Question 24

What is diapause

Answer 24

A developmental pause, often in response to environmental cues.

Question 25

What happens during the pupal stage

Answer 25

Larval tissues are broken down and adult structures form from imaginal discs.

Question 26

What is the imago

Answer 26

The final, reproductive adult stage of an insect.

Question 27

What types of insects exhibit holometaboly

Answer 27

Flies, beetles, butterflies, moths, ants, bees, and wasps.

Question 28

Are insect wings modified appendages

Answer 28

No — they evolved de novo from body wall outgrowths.

Question 29

What are the two theories of wing origin

Answer 29

Paranotal (thoracic outgrowths) and endite-exite (from gill-like leg branches).

Question 30

What are halteres

Answer 30

Stabilizing structures derived from hindwings in flies.

Question 31

What is synchronous muscle

Answer 31

Muscle contracts once per neural impulse.

Question 32

What is asynchronous muscle

Answer 32

Muscle can contract many times per single neural impulse.

Question 33

How does asynchronous muscle benefit flight

Answer 33

Allows extremely high wingbeat frequency.

Question 34

How many times has powered flight evolved independently

Answer 34

Four times — insects, birds, bats, pterosaurs.

Question 35

What is the notum

Answer 35

The dorsal (top) part of an insect thoracic segment, involved in wing attachment.

Question 36

Why are insects the most successful animal group

Answer 36

Wings, metamorphosis, adaptability, plant co-evolution, eusociality.

Question 37

How does complete metamorphosis aid success

Answer 37

Different life stages reduce intraspecific competition.

Question 38

What ecological metrics show insect success

Answer 38

Longevity, species richness, biomass, and ecosystem dominance.

Question 39

What is eusociality

Answer 39

Cooperative group living with division of labor and reproductive roles (e.g., ants).

Question 40

How does co-evolution with plants boost insect success

Answer 40

Pollination mutualisms and herbivory diversify niches.

Question 41

Why is the insect cuticle an important adaptation

Answer 41

Prevents desiccation, provides protection, and supports muscle attachment.

Question 42

What is a parasitoid

Answer 42

An insect that kills its host as part of its life cycle.

Question 43

What is a hyperparasitoid

Answer 43

A parasitoid that parasitizes another parasitoid.

Question 44

What adaptations help parasitoids succeed

Answer 44

Ovipositors with hardened tips for penetrating hosts.

Question 45

What are common insect disease vectors

Answer 45

Mosquitoes (malaria), lice (typhus), fleas (plague).

Question 46

What is entomophagy

Answer 46

The practice of eating insects — important in some ecosystems and cultures.

Question 47

What are chelicerae

Answer 47

Mouthparts in chelicerates used for feeding.

Question 48

What are pedipalps

Answer 48

Sensory/manipulative appendages in arachnids.

Question 49

What are pleopods

Answer 49

Crustacean limbs used for respiration (e.g. in woodlice).

Question 50

What led to the extinction of trilobites

Answer 50

Competition, predation, and the Permian mass extinction.