Biol 228 Invertebrates Test Flashcards
Memorise shit for the Practical test
What is Phylum Porifera?
Sponges
What are choanocytes?
Flagellated cells, lining the inner of the cell
What do ostia and oscula do?
Ostia: incurrent pores. Oscula: larger, outcurrent pores
What is the sponge’s supporting material?
Mesophyl. Contains skeletal elements, held in a gelatinous matrix
What is the purpose of choanocytes?
Use water current to capture food
Sponge structures, simplest to most complex
Asconoid, syconoid, leuconoid. Most sponges are leuconoid
How do sponges feed?
Filter feeders. Unselective
Reproduction
Both sexual and asexual
Hermaphrodites, but not at the same time
Types of asexual reproduction
Gemmules: Seed like capsule of cells held during adverse conditions, released when conditions improve, form new sponge.
Budding: Pieces break off and form new sponge
Aggregation: Disassociated sponge cells aggregate to reform a sponge
Characteristics of class Hexactinellida
'Glass Sponges' 6 ray spicules spicules made of SiO2 Marine Mainly syconoid or leuconoid
Characteristics of class Calcarea
Spicules made of CaCO3
All three construction types (Asconoid, syconoid, leuconoid)
Characteristics of class Demospongiae
95% of all sponges
Leuconoid
Spicules are SiO2, spongin fibres, or both
Sponge Ecology
Indeterminate growth, can be very big
Only eaten by specialised predators
can create own water current
Found on hard surfaces, shapes detemined by it
Do sponges have tissue layers?
No
What are phylum Cnidaria?
Jellyfish
What are the functions of nematocysts?
Stinging capsules. Defence and capture of prey
Body plan of nematocysts:
Sac with tentacles
Have opening that leads to gastrovascular cavity
Tissue layers?
- Ectodermal and gastrodermal w/ mesoglea (jelly) in between
Organs? Circulatory system?
No organs or circulatory system. Repiration, excretion and digestion by diffusion
What are polyps?
Cylindrical, thin mesoglea, hard skeleton, stationary
What are medusae?
Umbrella shaped, thick mesoglea, free swimming, no skeleton
Characteristics of class Hydrozoa
Most have polyps and medusae in life
What is a gatrsozooid used for?
Feeding
What is a gonozooid used for?
Reproduction
What is the layer of tissue around the bell shaped medusae called?
Velum
What is a Manubrium?
A stalk with a mouth on the end leading to Gastrovascular cavity. 4 Radial canals branch off
Characteristics of class Anthozoa
All polyps. No medusae
Has hydrostatic skeleton
Uses nematocysts to catch prey
What is pedal laceration?
Pinch off parts of ‘foot’ and walk away. Cloning.
How do Anthozoan’s reproduce?
Sexual or Asexual
Free spawn or internal fertilisation
Some hermaphrodites
What are the characteristics of class Scyphozoa?
True Jellyfish
Medusae dominated. Polyps reduced or non existant
No Velum
mouth is oral lobes
What are Rhopalia?
Finger like projections on outer of bell with sensory stuctures. Found in Scyphozoans.
What are characteristics of Platyhelminthes?
Flat worms Unsegmented 3 Tissue layers No body cavity (coelom) Hermaphrodites with Internal fertilisation
What are the characteristics of Class Turbelleria?
Ciliated epidermis- Particularly ventral (underside)
Digestive system variable in shape ans complexity
Turbellarian reproduction:
Sexual and asexual
Sexual complicated
Asexual- they can literally break themselves in half and regenerate
What are the characteristics of class Trematoda?
Parasites
Larval stage as parasites on invertebrates
Adult stage as parasites on vertebrates
What are the characteristics of class Cestoda?
Tape worms Larvae parasitic on invertebrates Adults live in digestive tracts of vertebrates No gut of their own Hold on with suckers
Characteristics of Phylum Annelida
Segmented
Closed circulatory system- vessels act like hearts
complete digestive tract
Nervous system
What does cephalised mean?
Has a head
Characteristics of class Clitellata
Leeches and Earthworms
Have a Clitellum- cylindrical glandular region of the epidermis
Used for reproduction
Hermaphrodites with permanent gonads
What is the subclass of earthworms?
Subclass Oligochaeta
What is the subclass of Leeches?
Subclass Hirudinea
Characteristics of class Polychaeta:
Marine Have Parapodia- outgrowth of body wall Seperate sexes- most free spawn Developed head with brain Deposit feeders Reproduction in accordance with the moon
Characteristics of Molluscs:
Bilaterally symmetric Cephalised Unsegmented Open circulatory system Nervous system
What are the 4 parts of a mollusc?
Head, foot, mantle, visceral mass
