Lab 7 Flashcards
What are Nematodes
Round worms
- Cylindrical body covered by exoskeleton (cuticle) that is shed (Ecdysis)
- Muscles are longitudinal → trashing motion
- non-segmented, Pseudocoelomates
What are the Coelomate divisions
- Acoelomate - no cavity between Endoderm and Ectoderm
- Pseudocoelomate - cavity between Endoderm and Ectoderm
- Coelomate - cavity in the Mesoderm, surrounded on all sides by Mesoderm
What is a Coelom
A coelom is a body cavity that is completely lined by mesoderm (not endo or ectoderm)
Different than a gut
Coelomates are divided into two groups based on developments: Protostomes and Deuterostomes
What is Phylum Arthropoda
- name means “jointed feet”
- jointed appendages and segmented bodies (tagma)
- all are ecdysozoans since they shed their exoskeleton (cuticle) to grow
- Diverse, numerous; widespread and successful
what are magma
Body segments that have a specific structure and function
what is subphylum chelicerate
- Chelicerae: claw-like feeding appendages
- No antennae
- Marine (horseshoe crabs) and terrestrial
- Most modern chelicerates belong to the Arachnida
what is class arachnida
- Six pairs of appendages
- One pair of Chelicerae; can be equipped with venom glands
- One pair of pedipalps - sensory, feeding, reproduction
- four pairs of legs
- e.g. mites, scorpions, spiders, ticks
what is subphylum myriadopa
- terrestrial
- 2 tagmata: head and trunk
- head
- one pair of antennae
- mouthparts include mandibles
- trunk
- uniramous (unbranched) appendages
what are diploda
Diplopoda: millipedes
- tube shaped body
- short antennae
- trunk: 2 pairs of walking legs/segment
- herbivorous
what are chelipoda
Chelipoda: centipedes
- flat body
- long antennae
- trunk: one pair of walking legs/segment
- carnivorous
describe subphylum crustacea
- tagma: 2 or 3
- 2 pairs of antennae
- chewing mouthparts include a mandible
- biramous (branched) appendages
- three or more pairs of legs
- e.g. crabs, crayfish, lobsters, shrimp
describe Insecta
Insecta
- 3 tagmata: head, thorax, and abdomen
- one pair of antennae
- Mouthparts
- modified for chewing, sucking, or lapping
- a mandible
- usually two pairs of wings
- often modified for other purposes
- Usually three pairs of legs
- Uniramous appendage
what is typical insect body plan
Includes a head, thorax, abdomen, antennae, eyes, mandibular mouth parts, 3 pairs of legs, 2 pairs of wings, tympanum, spiracles, and the ovipositor (female)
describe Echinoderms
- Eucoelomate Deuterostomes
-this group contains brittle stars, sea cucumbers, sea stars, and sea urchins - Secondary radial symmetry
- Bilateral larva > radial adult
- Hard calcareous endoskeleton
- Water vascular system
- Tube feet
- locomotion
- feeding
- gas exchange
describe subphylum Cephalochordata
Lancelets (or amphioxus)
- blade like or eel like shape
- small (few cm long) and bury in sand
- Chordate characteristics persist into adulthood
describe subphylum Urochordata
- uro = tail; chord = string
- marine, may be solitary or colonial
As larvae:
- Planktonic
- Short-lived
- non-feeding
- have all chordate characteristics
As an Adult:
- sessile
- no notochord, nerve chord, or tail
why are nematodes related to arthropods
Nematodes are related to Arthropods since they both periodically shed or molt their exoskeleton.
how can nematodes move
They trash side to side by contracting the long muscles on either side of their body and wriggling forwards. Since they only have longitudinal muscles, they can only move like this.
describe the shape of a nematode
All Nematodes are round with a body cavity. They have one way guts with a mouth at one end and an anus at the other. They have a pseudocoelom that is lined on one side with mesoderm and on the other side with endoderm.
