lab 10: annelida, nematodes, arthropoda

Question 1

reproduction for protosomes

Answer 1

-asexual: splitting the body
-parthenogenesis: unfertilized eggs develop into offspring
-sexual: external & internal fertilization

Question 2

2 unique reproductive innovations

Answer 2

-metamorphosis= process from immature to adult in 2 or more distinct stages
-eggs don’t dry out

Question 3

adaptations from water to land transition

Answer 3

-exchange gases
-avoid drying out

Question 4

phylum nematoda (roundworms): chapter 38

Answer 4

-lack flagella & cilia
-covered with cuticle
-separate sexes & undergo internal fertilization

Question 5

the 2 morphological advances absent in flatworms

Answer 5

-pseudocoelom= consists of fluid-filled space between body wall & digestive tract
-nematodes have complete digestive tract with mouth & anus

Question 6

phylum annelida: segmented worms

Answer 6

-septa: act as walls between the segments, prevents fluids from moving between segments
-each segment has parts of circulatory, digestive, nervous & excretory system
-closed circulatory system
-setae (filter feeding & defense) that extend from appendages called parapodia (help move & respire)
-reproduce sexually & asexually

Question 7

phylum annelida class polychaeta

Answer 7

-has setae
-mostly marine living in sediments
-sand worms, etc
-polychaeta = many hairs

Question 8

phylum annelida class oligochaeta

Answer 8

-earthworms & many freshwater species
-moist soils, freshwater or marine environments

Question 9

phylum annelida class hirudinea (leeches)

Answer 9

-moist terrestrial, freshwater, marine environments
-smaller coelom
-ectoparasites, predators or scavengers
-lack setae: unsegmented worms
-sexual reproduction: hermaphroditic

Question 10

phylum arthropoda

Answer 10

-open circulatory system
-segmented bodies, jointed exoskeletons, reduced coelom, body cavity (hemocoel)
-tagmata: head, thorax & abdomen
-grow by molting (shedding cuticle or exoskeleton)
-compound lenses
-analogous: 2 different species that have similar functions but different origins
-homologous: 2 different species that have similar origins but different functions

Question 11

phylum arthropoda subphylum crustacea

Answer 11

-lobsters, shrimp, crabs, crayfish
-have 2 segmented body divided into the cephalothorax (head & thorax) & abdomen
-sexual reproduction

Question 12

phylum arthropoda class cnelicerata

Answer 12

-spiders, ticks, mites, daddy longlegs & scorpions
-lacks antennae
-sexually via internal fertilization

Question 13

phylum arthropoda class merostomata

Answer 13

-horseshoe crabs

Question 14

phylum arthropoda class arachnida

Answer 14

-scorpions, ticks, mites, daddy longlegs
-spiders have 2 body segments & 8 legs
-insects have 3 body segments & 6 legs

Question 15

phylum arthropoda class diplopoda (millipedes) & class chilopoda (centipedes)

Answer 15

-millipedes= detritivores, live in soil & under rocks, 2 pairs of legs per segment
-centipedes= predatory carnivores, poison their prey, 1 pair of legs per segment
-myriapod sexes are separate & internal fertilization; females lay eggs

Question 16

phylum arthropoda class insecta

Answer 16

-distinguished by head, thorax & abdomen (tagmata)
-3 pairs of walking legs on the ventral thorax
-2 pairs of wings attached to the dorsal thorax