Passage map:
Overall the passage describes how a recent discovery concerning the Ant-eaters electroreceptors was made.
P1 – describes the experiment that led to the discovery and dispels the potential that the discovery is an alternate (tactile)
P2 – Applies the discovery to practical application – how the anteaters use it and some unexplainables.
Q1A is incorrect as it is not the manner of response but the degree of stimulation required to get a response
B is incorrect because this cannot be supported
C is again not supportable
D is supported by the last sentence of the first para. , which states that although tactile sensors are triggered in the same way, the difference is that tactile requires 1000x greater electrical field strength
E ‘excited’ makes E incorrect
Q2 The first para. Describes an experiment in which two disparate electric stimulations were applied to small areas of the snout of the ant-eater – 1 low electrical field and 1 electrical field 1000x greater.
What can we infer?
A is incorrect for a number of reasons. Firstly, it seems researchers didn’t really have difficulty; second, the electroceptors were exposes to a large, not ‘narrow’, range.
B is false. We are told that “nervous activity TO THE BRAIN” not “IN THE BRAIN” increased.
C is correct because some receptors responded to weak electric fields, others responded to electric fields 1000x greater, so we can infer that “others” weren’t sensitive i.e. if they were sensitive then they wouldn’t require 1000x stimulation.
D is incorrect because logically the electroreceptors must be triggered first (before) the tactile receptors. E is false. We are told that electroceptors were discovered by exposure to weak electrical fields. The researchers didn’t explicitly test for the electroceptors. We are told that the reseachers “discovered” electroreceptors by “recording the transmission of resulting nervous activity “
Q3Read the highlighted part and think about WHY this is in the passage.
Here, the author brings up tactile receptors, which are ALREADY KNOWN (as inferred since electro are only just discovered), to dispel/ refute the possibility that these may be the receptors causing the results that were seen.
Now imagine if the author hadn’t stated this in his passage and some random scientist came across and asked “what about tactile receptors? You forgot that these could be the cause”>?
A captures the above perfectly.
B is incorrect. The tactile may be similar but that’s not why the author brought this up.
C is incorrect – its not a complication, the author is merely dispelling
D is incorrect because the author points out two dissimilarities, not similarities
E is incorrect because the author does not bring this up to discuss something that wasn’t included in research. He dispels!
Q4The experiment in question is a behavioural experiment in which researchers trained the ant-eater to differentiate between two troughs of water based on electric signals.
A is incorrect because the experiment only involved a ‘weak electric field’, and we know that tactile is triggered by 1000x greater fields
B is incorrect – we don’t know this. In fact later on we are told that electric signals aren’t given off.
C is correct – it can be 100% supported since the researchers trained the anteaters to detect a stimuls.
D is incorrect since we have no information on the ‘readiness’ by which the anteaters respond to stimuli
E is incorrect since we can’t support how anteaters interact between environments
Q5The researchers in question observed anteaters break into nests that weren’t emitting signals, and eat their prey at oblique angles, quickly.
A is incorrect – the finding is generally weak. We are told that the reasearchers “as yet have been unable to detect” signals, so the observation isn’t exactly conclusive.
B – knowing what “atypical” means can help – it means “not representative”- if all this time we are told of evidence relating to one ant-eater then how can another observation relating to one ant-eater be non-representative?
C I incorrectly selected this. But I see that its incorrect as the observation was in fact used as evidence to support the claim the anteater uses their electroceptors for this hunting.
D is incorrect – probably the easiest to eliminate. We know the system isn’t exactly simple. If it were then the scientists would produce conclusive and strong conclusions.
E is correct because we are told that “researchers observed anteaters breaking into a nest….at an oblique angle and quickly locating nesting chambers”
This is analogous to someone walking into their bedroom at nighttime with the lights turned off and getting into bed. This person would rely on other sensors to navigate his way as well as his familiarity. What’s insinuated by E is that the fact the anteaters got into the nests awkwardly, but so quickly, makes it hard to believe that the anteater got lucky in identifying the ants.
Q6The hypothesis is that anteaters detect prey via electroreceptors.
What have we got to believe this?
Pretty weak evidence – an observation (noted in Q5 above).
We need to strengthen this.
A – the ability to train the anteaters to detect STRONG signal does not serve as evidence to support the notion that anteaters rely on their electroreceptors, which detect WEAK SIGNALS.
B – This would 100% strengthen. It would explain why anteaters are so QUICK at locating prey.
C – This would weaken the hypothesis. How would this strengthen? It wouldn’t. It goes against the observation also.
D – It was moreso the QUICK ability of the anteaters to locate their prey. We need something that shows a reliance on electroreceptors and this answer choice just doesn’t do that.
E – the angle itself isn’t what led scientists to hypothesize that anteaters rely on their electroreceptors, again, it was the QUICK ability. This doesn’t strengthen.
_________________