New evidence supporting conclusion ·Neurophysiological studies
Studies reveal two sensory receptors in pores on platypus bills: mechanoreceptors (respond to physical pressure), and electroreceptors (respond to electrical fields).
Puzzle ·How does platypus locate prey at a distance?
If a platypus isn't touching its prey with its bill, how can it find the prey? (Probably has to do with the electroreceptos, since we discussed the mechanoreceptors earlier.)
Scheich's speculation ·All invertebrates that platypus eats produce electric fields
We already know that shrimp prey of platypus produces an electric field.
Passage Style
Phenomenon-hypothesis (RC)
Single position
20.
It can be inferred from ███ ███████ ████ ██████ ██████████ █████████ ███ ████████ ██ ██████████ ██
Question Type
Implied
During patrolling behavior, the platypus “swims along, steadily wagging its bill from side to side until prey is encountered.” After encountering prey, it “switches to searching behavior ... which is followed by homing in on the object and seizing it.” This suggests that during patroling behavior, the platypus is trying to find prey. As the rest of P2 suggests, the platypus is likely trying to detect electric fields produced by prey.
a
capture prey that ██ ███ ████████
It hasn’t detected prey yet during the patrolling phase.
2%
b
distinguish one kind ██ ████ ████ ███████
We have no reason to think the platypus is trying to distinguish fish from shrimp. It’s trying to distinguish non-prey (a rock, for example) from prey.
3%
c
detect electric fields ████████ ██ █████████ ████
Supported, for the reason explained above.
88%
d
stimulate its mechanoreceptors
The platypus is trying to find electric fields. This involved electroreceptors, not mechanoreceptors.
5%
e
pick up the █████ ██ ███ ████
The platypus doesn’t hunt by picking up the scent of prey.
2%
Difficulty
88% of people who answer get this correct
This is a moderately difficult question.
It is similar in difficulty to other questions in this passage.
CURVE
Score of students with a 50% chance of getting this right
25%130
142
75%154
Analysis
Implied
Implied
Stems asking us to infer an idea implied by the claims in the passage (as opposed to identifying an idea that appears explicitly). Similar to most strongly supported questions in LR.
Passages that focus on describing or evaluating potential explanations for a given phenomenon. Causal reasoning features prominently in these passages.
