Revision

Question 1

1. What are four mechanisms that aid suspension feeders and how? (4)

Answer 1

Setose appendages trap coarse particles and move to mouth
Mucous bags are filled with particles from flowing water and then consumed
Ciliary mechanisms beat to provide a current and trap small particles
Tentacles/tube feet can suction/grab particles

Question 2

List 3 types of cannibalism in invertebrates (3)

Answer 2

Juvenile, matriphagy, sexual

Question 3

Using Dow’s method of classification, compare and contrast the diet of a mantid and
a sap-sucking bug (2)

Answer 3

Mantis – animal, SSB – plant; mantis – solid, SSb – liquid

Question 4

What are 3 disadvantages of a nutritionally unbalanced diet? (3)

Answer 4

Energetically costly to keep eating, excess nutrients may be toxic, metabolically costly to convert carbs to protein.

Question 5

Mention 5 adaptations found in insect mouthparts for different diets. Give an example
of each (5)

Answer 5

Chewing – grasshopper
piercing and sucking – mosquito
siphoning – butterfly
sponging – house fly
chewing and lapping – honeybee.

Question 6

Give an example of a type of locomotion that has evolved convergently in different
taxonomic groups? Which 2 groups would display this locomotion? (3)

Answer 6

Undulatory swimming. Nematodes and polychaetes.

Question 7

How is leg interference prevented in invertebrates? (2)

Answer 7

Placement of adjacent leg tips at different distances from the body. Legs of slightly different lengths move in a tripod sequence.

Question 8

What is the difference between undulation and oscillation in terms of aquatic locomotion? (4)

Answer 8

Undulation – sinusoidal movement, usually passes through entire body.
Oscillation, a flapping back and forth movement, usually confined to parts of the body.

Question 9

Explain what is meant by wing loading (5)

Answer 9

Defined as the ratio of body mass to wing area.
High wing loading = large body mass to wing area. Provides a measure of energetic cost of flying i.e. larger loading = higher cost. High wing loading in species inhabiting complex structures – a need to manoeuvre.
Low wing loading – migratory species for sustained periods of flight.

Question 10

Excluding flight, list two types of aerial locomotion and provide an example of each (2)

Answer 10

Ballooning – spiders using silk
Gliding – ants contorting abdomen

Question 11

What is the purpose of gas exchange? (5)

Answer 11

Uptake of O2, release of CO2, metabolism, equation, release of energy for development and
maintenance.

Question 12

What are the 4 main respiratory organ systems found in invertebrates? (2)

Answer 12

Tracheae, book lungs, gills, skin/integuement

Question 13

What are 6 main hypotheses re: the function of discontinuous gas exchange in insects? (3)

Answer 13

Hygric
Chthonic
H-C
Oxidative damage
Strolling arthropods
Emergent property

Question 14

What is a physical gill? Cite 3 examples of physical gills in invertebrates (4)

Answer 14

A physical pocket of air. Diving bell spider (book lungs), diving beetle air bubble (tracheae), riffle beetle plastron (tracheae)

Question 15

Explain the difference in respiration between the horseshoe crab and all other true crabs (brachyurans) (3)

Answer 15

Horseshoe crabs – book gills, modified movable appendages (swimming), exposed,
operculum (cover).
Brachyurans – true gills, enclosed, water moves over independently

Question 16

Why are lipids a bad source of water? [1]

Answer 16

Need an O2/H2O balance and O2 requirements to metabolise lipids are high

Question 16

Differentiate between an osmoconformer and osmoregulator, giving one example of each [3]

Answer 16

OC – no energy spent, iso-osmotic.
OR – spends energy, adjusts internal osmolarity

Question 17

What is a cryptonephridial complex and how does it help regulate internal osmolarity?
[3]

Answer 17

Association of Malpighian tubule and rectum, bound by perinephric membrane (3). Pumps
K+ ions into Malpighian tube, higher osmotic concentration, reabsorption of water from
rectum.

Question 18

Explain how earthworms excrete waste [6]

Answer 18

Metanephridia, one in each segment, coelomic fluid into collecting tubule, closed capillary
network closely associated, transport epithelium, reabsorb nutrients from urine, out through
nephridiopore.

Question 19

How do terrestrial invertebrates get water from food? [2]

Answer 19

Metabolic water, describe or write out equation!!