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.
