Ecdysozoa: insects and nematodes

Question 1

arthopoda

Answer 1

insects, spiders

Question 2

insects

Answer 2

external hard skeleton which moults for growth and provides inherent support
curiticle waterproofed by waxes; cuticle lined trachea (avoid water)
jointed limbs for locomotion and feeding
use metabolic pathway; generate uric acid

ONLY FLYING INVERTEBRATES

Question 3

arthopoda shared characteristics

Answer 3

segmentation

rigid skeleton

Question 4

insect modification of segmentation

Answer 4

have ‘tagmata’; three principle units fused together with a flexible neck joint coming out of thorax and pairs of wings
= seperation of functions for optimization of body

Question 5

why do insects have two pairs of wings

Answer 5

• they didnt evolve from legs; therefore not contrained as bats/birds (as they need one limb for walking adn the other for flying)
• allows for greater diversity of flying styles

Question 6

examples of insects

Answer 6

dragonflies, cockroaches, fleas, flies

Question 7

big four orders of insects

Answer 7

beetles; coleoptera

butterflies/moths: lepidotera

bees, wasps, ants; hymenoptera

flies: dipteria

Question 8

lepidotera

Answer 8

• 2 pairs of wings
• wings can move indepdenetly
• vary a lot
• are pretty; moarch butterflies

Question 9

coleoptera

Answer 9

single paired wings for flight

- beetles have developed into flight wings and protected case; allows for burrowing into soil and seed

Question 10

hymenoptera

Answer 10

controlled flight to collect nectar and catch pray
evolution of colonies of indiviuals living together; haplodiploidiy

• males have half the number of chromosomes than femaes; hence cooperation between sisters is evolutionary favourable to propomote survivial of genetic lineiage (shared defense of resources by relatives and breedign system)

Question 11

dipteria

Answer 11

hind wings turned into halteres to cibrate up and down; can tilt from side to side and have prcise orietantion

mosquitoes carry malaria

drosphila flies can be polinators and give gene functions

Question 12

chelicerates

Answer 12

arthopod; spiders and scorpoions

Question 13

myriapods

Answer 13

arthopod; centipedes and milipedes

Question 14

myriapod traits

Answer 14

specialize head
segements with many jointed legs; diplosegments
have trachea to deliver oxygen to tissues

centipedes; predators with poison claws

milipeeds; eat wood or decaying leaves

Question 15

change of relations in arthopods?

Answer 15

• use to be that myriapods and inscects were believe to be closely related;
• however molecular evidence shows insects closer related to crustaceans= evolved in land and sea seprate

Question 16

crustacean

Answer 16

crabs, lopsters, shrims, fish lice, barnacles

Question 17

whats unusual about barnacles

Answer 17

start off as free swimming larvae then settle down onto rocks and become filter feeders

Question 18

tardigrades

Answer 18

closer relatives to arthopods; are microscobic ‘water bears’

• found on water on damp moss/liches
• remarkable ability to withstand extremte temperatures
• can enter a state of suspended animation (crptobiosis); reduce consumption of oxygen and water

Question 19

oynchophorans

Answer 19

'velvet worms'
live on land
look like furry catterpillars 
are hunters
have appendanges from side of head 
shoot prey

Question 20

nematodes

Answer 20

round worms
unsegemented
no external skeleton 
no limbs 
live in soil or rotting vegetation

Question 21

dna evidence and nematodes

Answer 21

indictate they are close related to arthopods, water bears and velvent animals

Question 22

what do all ecdysozoans have in common

Answer 22

ecdysis; they moult/shed skins as they grow ‘ moulting animals’

Question 23

internal structure of nematodes

Answer 23

• coelom
• internal pressure pushes against nematodes tissues/cuticles
• longitutunal oriteitation of body muscles
• move using the high pressure coloem and elastic sptringly cutiricle to conteract muscles and move in a ‘thrashing’ motion

Question 24

nematomorpha

Answer 24

thin worms; ‘horsehair worms’
tough cutircle
longitudinal musccle

they dont eat anything (only babies do; eat host)

live in water + manipulate behaviour of host to jump into water