Zoology week 2

Question 1

Lophotrochozoa

Answer 1

one of the three triploblastic, bilateral super phyla, have trochophore larvae or lophophore

Question 2

Platyhelminthes

Answer 2

Phylum: flatworms, no synapomorphies, parenchyma, unsegmented, cephalised, excretory/osmoregulatory systems

Question 3

Turbellaria

Answer 3

Platyhelminthes class: flat shape for gas diffusion, ciliated epidermis, mesoderm + gastrodermis (single cell layer for max diffusion), contraction of muscles for movement, pharynx in centre of body, cerebral ganglia, traverse fission and muller’s larvae, have protonephridia for excretion and osmoregulation

Question 4

Trematoda

Answer 4

Playhelminthes class: flukes; wide + flat shape, mostly parasites, have an oral end and a diffused gut

Question 5

Monogenea

Answer 5

Playhelminthes class: 1 generation: adults hatch directly from eggs, mostly exoparasites

Question 6

Cestoidia

Answer 6

Playhelminthes class: tapeworms, live in host digestive system, no mouth: ready digested for absorbed over body wall, consist of repeating united called proglottids that contain their own reproductive elements

Question 7

Annelida

Answer 7

Phylum: metamerism, trochophore larvae, closed circulatory system (dorsal + ventral aorta), coelomate, locomotion through muscle contraction, setae+parapodia to dig into substrate, segmental ganglia, excrete ammonia and urea across body wall: protonephridia or metanephridia for osmoregulation

Question 8

Errantia

Answer 8

Annelid class/clade: mostly marine, prominent lobes and parapodia, long setae

Question 9

Sedentaria

Answer 9

Annelid class/clade: parapodia with reduced lobes, usually more sedentary burrowers: includes clade Clitellata (earthworms, leeches etc) that have clitellum (egg sacks) and secrete mucus during copulation, few or no setae

Question 10

Basal annelids

Answer 10

Annelid class/clade: unusual because have no segmentation, live in U-shaped parchment tubes and feed by circulating water or burrow in sand/mud and extend mouthparts for feeding

Question 11

Acoelomorpha

Answer 11

lophotrochozoan phylum: no eyes or photoreceptors, ‘less developed’ than playhelminthes, only 4-5 hot genes, could be considered first bilateral organisms

Question 12

Ecdysozoa

Answer 12

second triploblastic bilateral super phyla: secrete a three-layered non-living cuticle which is shed as the organism grows

Question 13

Nematoda

Answer 13

Ecdysozoan phyla: cutie made of collagen, very diverse, parasitic or free living, no cilia, full digestive tract with mouth and anus, specific number of somatic cells in some species.
Renettes (aquatic) or tubular excretory systems (parasitic)
dioecious and dimorphic

Question 14

Rotifera

Answer 14

Lophotrochozoan phylum: psuedocoelomate with lophophores