Practive Qs Flashcards
By means of a labelled diagram, outline the lifecycle of Plasmodium falciparum.
Draw labelled diagrams to show how the mesoderm is arranged in a) an
acoelomate, b) a pseudocoelomate and c) a coelomate animal.
Describe the polymorphism seen in the cnidarians.
- Polyp: tubular, sessile
- Medusa: bell shaped, free swimming
- Alternate gens in schyphozoans and some hydrozoans
- Siphonophores: coloinal zooids
- Corals: specialised polyps
How is an adult tapeworm adapted to a parasitic life?
- Proglottids –> allow self fertilisation
- Scolex: head with hooks and suckers
- Tegument: protection from digestive and immune system
- No gut, no eyes
How does a hydrostatic skeleton work?
- Fluid filled cavity (coelomic fluid/hemolymph)
- Incompressible fluid maintains support
- Muscles surround, creating internal pressure. Contraction/relaxation = movement
Describe how urine is produced by a) protonephridia and b)
metanephridia.
Proto:
- Flame cells waft fluid into tubules
- Useful reabsorbed
- Primary urine expelled
Meta:
- Fluid forced out by muscular contraction = into coelom
- Goes through metanephridium = useful reabsorbed
- Urine expelled
What is torsion in gastropods? What disadvantage would torsion have presented to the ancestral gastropod?
Torsion: 180 degree rotation of viseceral mass during verliger larval stage
Disadvantage:
- Twisted struc = incresed risk of waste materials contacting respiratory system
- Anus in head region increases risk of contamination of sensory organs
What are the features of the Echinodermata?
- Radial symmetry in adults
- Tube feet
- Mutable connective tissue
- Deuterostomes
- Regeneration ability
Why are the hemichordates not regarded as chordates?
- No notochord
- No post anal tail
- Pharyngeal gill slits different struc and function
- Ventral noto cord (rather than dorsal)
Name two adaptations that allow insects to feed on plant sap and explain
how these adaptations function
Piercing/sucking mouthparts
- Needle like stylet penetrates phloem
Filter for excess water
- Filter chamber in insect digestive system to help get rid of excess water from sap
What is the difference between holometabolous and hemimetabolous
development?
Holo:
- Complete metamorphosis (4 morphologically distinct life stages: egg, pupa, larva, adult)
Hemi:
- Incomplete (3 stages: egg, nymph, adult ) Juvelile resembles adult
Name the most significant synapomorphy of Lepidoptera and explain its
function.
Wing scales (modified setae)
- Colour and camo
- Thermo reg
- UV reflection and detection
- Water repellence
- etc.
What are the key features of the sponges?
- Radiata
- Diploblastic
- Osculum (with porocytes, choanocytes, amoebocytes)
- Spicule - skeleton
- Asexual budding
- Sexual: External fertilisation
What are nematocysts? What are they used for and in which animals are
they found?
- Stinging cells consisting of a thorn and a barb
- Used for defence against predators and for predation
- Cnidarians
Giving an example, what are the key adaptations for parasitism seen in
the platyhelminths?
Cestoidea: Tape worms
– Proglottids –> allow self fertilisation
- Scolex: head with hooks and suckers
- Tegument: protection from digestive and immune system
- No gut, no eyes
Describe how the insect exoskeleton functions to allow flight in winged
insects.
- Indirect (doesn’t directly use muscles)
Dorsoventral muscles CONTRACT (longitudinal relax) = flexible zone pulled → nodal hinge down → wing snaps UP
Longitudinal muscle CONTRACT (dorsoventral relax) = flexible zone pulled → nodal hinge pulled up → wing snaps down
By means of a labelled diagram, outline the lifecycle of the pin worm.
Giving an example, what are the key features of the chelicerates?
E.g Horseshoe crab
- 2 tagmata: Prosoma, opisothoma
- Chelicerae → first appendages
- Pedipalps → second appendages (walking legs)
How is the Pompeii worm adapted to its environment?
Tolerates high temps (80OC)
Deposit feeder
Dorsal surface colonised by bacteria
How has the basic molluscan body plan been modified in the
cephalopods?
- Dorsal-ventral orientation now
- Shell replaced/absent
- Foot modified to tentacles
- Modified radula for predation
What are the key features of the annelids?
- Coelomate
- Metameric segmentation
- Metanephridium
What are the advantages and disadvantages of living in the marine
environment for invertebrates?
Ad:
- Buoyancy: can support bodies more easily than terrestrial
- Higher O2 content than terrestrial
- Stable temp (SHC)
- Dispersal of larvae
Dis:
- Osmotic regulation
- Desiccation risk at low tide
- Wave action and turbulance
