Bio 193 Ch. 33 Nematoda/Arthropoda

nematoda

a phylum of unsegmented worms known as roundworms, characterized by a cylindrical body and complete digestive tract.

epidermis of threadlike body lacks____

membrane

nematoda secrete and periodically

molt their outer cuticle to grow.

nematoda are found

everywhere

nematoda size range

mm to very large

nematoda considered most ____ animals on earth

numerous

nematoda do not have

segmented bodies, complete alimentary canal, seta, and a circulatory system

nematoda reproduction

internal fertilization (many eggs)

nematoda do have

nervous system and muscle

nematoda longitudinal muscles

lateral bending but no lift

phylum arthropoda

a diverse group of invertebrates characterized by jointed legs, exoskeletons and segmented bodies.

arthropoda have

segmented bodies and jointed appendages

arthropoda are completely covered by

hard exoskeleton

hard exoskeleton used for

protection, slow water loss, spots for muscle attachment

exoskeleton constructed of

chitin and proteins

ecdysis

molting shell (costly and vulnerable)

arthropoda occupy all habitats because of

exoskeleton

tagmata

fused segments that enable functional specialization

altered hox gene led to

segment fusion in arthropods

specialized resp. system in arthropods, WATER

gills (tissue extensions, increase SA)

specialized resp. system in arthropods, LAND

tracheal system or book lungs

traits of arthropods resp. system for high activity

thin respiratory surfaces, lots of SA, wet (gas must dissolve to cross plasma membranes)

arthropoda have a variety of

sensory organs (simple/compound eyes, antennae, chemoreceptors)

metamorphosis reduces

competition for resources between adults and larvae.

cheliceriformes

a group of arthropods that includes spiders, scorpions, and horseshoe crabs, characterized by their chelicerae, 1-2 body parts, and lack of antennae.

where are cheliceriformes

mainly terrestrial

chelicerae

claw like feeding appendages

majority cheliceriformes are

spiders

poison is used to

help liquify prey

unique specialized glands in cheliceriformes

silk glands

pancrustaceans

group of arthropods such as lobsters, shrimps, crabs (2-3 body segments)

crustaceans are found in

aquatic (freshwater and marine)

crustaceans have highly specialized

appendages (2 pair antennae, mouthparts, legs for swimming)

myriapods

group of arthropods that includes centipedes and millipedes, characterized by having numerous body segments and legs. (3 body parts)

myriapoda found where

terrestrial

myriapoda have a pair of

antennae and 3 pairs of feeding parts

millipeds have ___ pairs of legs per body segment

2

millipedes eat

plants (herbivores)

centipedes have __ pair of legs per

1

centipedes eat

meat (carnivores)

insects have

3 body parts and 6 legs

more species than all other groups combined

insects

insects are very abundant in all habitats except

marine

many insects are capable of

flight (wings not true appendages)

flight advantage

aids in escaping predators and finding food or mates and dispersal

an insect larva focuses on

growing (no wings)

an adult insect focuses on

reproduction and mating (have wings)