IELTS Reading tests how well you can locate specific information within a passage under time pressure, using question types like matching information, diagram labelling, and summary completion to check different reading skills in a single go.
This passage, called Electroreception, comes from the British Council's IELTS Reading Actual Test 03. It's a popular one in practice banks because it combines matching information, diagram labeling, and summary completion in a single passage, making it a solid test of three different reading skills at once.
Here's the official answer key for the Electroreception passage:
Question
Answer
Question Type
1
C
Matching Information
2
G
Matching Information
3
B
Matching Information
4
A
Matching Information
5
H
Matching Information
6
D
Matching Information
7
respiratory movements
Diagram Completion
8
tail
Diagram Completion
9
electric currents
Diagram Completion
10
olfactory organs
Summary Completion
11
electric signals
Summary Completion
12
sinewy muscle
Summary Completion
13
electric field
Summary Completion
Here, we have given you a similar kind of practice passage with the same type of questions to solve. We have also given the answers and explanations below, so try the passage first, and only check the key afterward to see why each answer is correct.
Want to understand the complete IELTS test before practising Reading passages? Check the IELTS Exam page for the test format, sections, duration, and key details.
Electroreception IELTS Reading Passage for Practice
A passage that reads exactly like the one you practiced on already won't teach you much on test day, since the real exam will phrase everything differently. What actually helps is a version that keeps every fact, every animal example, and every paragraph's purpose intact, just worded differently.
That's exactly what's below. Same eight paragraphs, same scientific details about rays, sharks, and weakly electric fish, same order of information. Read through it at a normal pace first, try spotting where each answer might live, then check yourself against the explanations further down.
Electroreception IELTS Reading Passage for Practice
Paragraph A: Underwater, vision doesn't get you far. Colors blur into murky green, and sound turns muffled and hard to place. Humans dropped into these conditions without gear would be completely lost, yet fish move through it like it's nothing. Much of that comes down to electroreception, the ability to sense and respond to electrical signals as part of an animal's regular senses. Only creatures living in or near water have this ability, since water conducts electricity so well.
Paragraph B: Electroreception splits into two types. Every animal, humans included, gives off electric signals naturally through the nervous system. Some animals, though, can actually pick up and interpret those signals coming from other creatures, which lets them figure out where those creatures are. This receiving-only version is called passive electroreception.
Paragraph C: Some animals take it further. Active electroreception means the animal has organs built specifically to produce its own electric signals on command. These signals serve multiple purposes, attracting mates, marking territory, and locating objects in the water around them. Because different objects and creatures create different resistance against these signals, active electroreceptors can tell the difference between prey, predator, or something worth ignoring entirely. The range on this sense stays fairly short, about one body length, just enough time to react.
Paragraph D: One particularly interesting use of active electroreception shows up in weakly electric fish, through something called the Jamming Avoidance Response. When two of these fish end up using the same signal frequency near each other, one of them shifts its frequency so they're no longer overlapping. This stops their electroreception from getting jammed or confused. Long before humans figured out radio frequency conflicts needed sorting out, these fish had already worked out their own version of the same problem.
Paragraph E: Electroreception also plays a defensive role, and ray embryos are a strong example. These embryos grow inside egg cases anchored to the seafloor, constantly moving their tails to pump water through the case so they can breathe. The moment their electroreceptors pick up a nearby predator, that tail movement stops completely, cutting off the electric signal too, until the threat passes. This response only triggers for signals matching a predator's actual breathing pattern, since plenty of harmless marine life passes by without ever setting it off.
Paragraph F: Sharks are usually the reason people hesitate before swimming in open water, and that hesitation isn't baseless, since humans have zero electroreceptive defenses of our own. Sharks, on the other hand, hunt with serious precision. Smell does the early work, a huge portion of a shark's brain is dedicated purely to detecting scent. Once it's close enough, electroreception takes over completely, guiding the final strike so precisely that sharks can even attack with their eyes rolled back for protection.
Paragraph G: Most shark attacks on humans happen by mistake rather than intent. Since electroreception can't tell a shark whether something actually tastes good, sharks often test a target with one exploratory bite before deciding whether to continue, and human muscle tends to disappoint compared to softer prey like seals. Once blood enters the water though, things change fast. Salt in blood strengthens the electric field significantly, which raises the odds of a repeat attack. This has pushed some researchers to explore artificial electroreceptors that could disorient sharks near swimming areas.
Paragraph H: Plenty about electroreception still isn't fully understood. Researchers have observed how it shapes hunting, defense, and communication, but the exact neurological process behind encoding and decoding these signals remains unclear. One active area of research looks at navigation, specifically whether the interaction between salt water and the Earth's magnetic field might generate currents that sharks use to migrate long distances.
You have now read the passage about electroreception, how it works, and the different ways aquatic animals use it. The questions below will test how well you can locate specific facts, follow the connection between passive and active electroreception, and match small details to their exact place in the passage.
Read each question carefully before answering. A few answers are stated directly, but most use slightly different wording than the passage itself, so focus on the meaning behind each question rather than hunting for identical words. This practice set uses the same paraphrased passage from above, but with a completely different mix of questions than the official test, so you're reading for real answers here instead of recalling ones you've already seen.
Here's how the practice set breaks down before you start.
Question Range
Type
What It's Testing
1–6
Matching Information
Locating specific details across paragraphs
7–9
Diagram Completion
Precise wording from a specific section
10–13
Summary Completion
Connected facts pulled from a full passage
This set checks the same reading skills as the real test, locating details, filling gaps with exact wording, and following a connected summary, just built around a different set of questions so you get real practice.
Eight paragraphs, six questions, so a couple of paragraphs won't get used at all. Read through the whole passage once before matching anything, since some clues sound similar at first glance.
Which paragraph contains the following information? Write the correct letter, A–H, for each.
The reason electroreception only exists in creatures living in or near water
The definition of the type of electroreception that only receives signals
How active electroreception helps tell prey, predator, or neither apart
What happens when two electric fish end up using the same signal
Why humans are considered poorly defended against shark attacks
A technology scientists are developing to protect swimmers from sharks
Questions 7–9: Diagram Completion
This part zooms into the Jamming Avoidance Response section of the passage. Choose NO MORE THAN TWO WORDS from the passage for each blank.
This mechanism is called the (7) ___ Response. It has been observed in (8) ___ fish. Shifting frequency stops the signal from becoming (9) ___.
Questions 10–13: Summary Completion
This summary covers how ray embryos defend themselves. Choose NO MORE THAN THREE WORDS from the passage for each blank.
Ray embryos grow inside egg cases attached to the seabed, keeping their tails in (10) ___ to pump water through the case and breathe. If electroreceptors detect a nearby predator, the embryo stops moving completely, which also cuts off its (11) ___. This response only triggers for signals matching a predator's (12) ___, since plenty of harmless (13) ___ passes by without setting it off.
Once you've worked through the practice questions above, use the electroreception reading answers with location below to check your responses and see exactly where each one sits in the passage. Checking your answer alone tells you if you got it right, but the explanation is what actually helps on the next passage too, since these small reasoning patterns tend to repeat across different science-based texts.
Every answer below comes with its exact location and a clear reason why it fits, so you can spot where a small wording difference might have thrown you off.
Answers and Explanations of 1–6: Matching Information
There are six questions in this part, each one matched to a specific paragraph based on one clear detail rather than the paragraph's general idea. The table below shows the quick version first, correct answer next to each question, followed by the full reasoning for each one.
Question
Answer
1
A
2
B
3
C
4
D
5
F
6
G
Q1: The reason electroreception only exists in creatures living in or near water A: A Location: Final line of paragraph A Explanation: The passage closes by saying water conducts electricity well, which is exactly why this sense stays limited to aquatic and amphibious animals.
Q2: The definition of the type of electroreception that only receives signals A: B Location: Second half of paragraph B Explanation: Passive electroreception is defined here as receiving and decoding signals from other animals, with no mention of the animal sending out its own.
Q3: How active electroreception helps tell prey, predator, or neither apart A: C Location: Middle of paragraph C Explanation: The passage says active electroreceptors can sense different resistances in the water, and that's exactly how they tell whether something nearby is worth eating, avoiding, or ignoring.
Q4: What happens when two electric fish end up using the same signal A: D Location: Middle of paragraph D Explanation: This paragraph explains that one fish shifts its frequency so the two signals no longer overlap, keeping their electroreception clear.
Q5: Why humans are considered poorly defended against shark attacks A: F Location: Opening of paragraph F Explanation: The passage states plainly that humans have zero electroreceptive defenses, unlike sharks, which hunt with serious precision using this exact sense.
Q6: A technology scientists are developing to protect swimmers from sharks A: G Location: End of paragraph G Explanation: The passage mentions artificial electroreceptors being explored specifically to disorient sharks and keep them away from swimming beaches.
Answers and Explanations of 7–9: Diagram Completion
Three blanks here, all pulled from the same short stretch of the passage covering the Jamming Avoidance Response. The table below shows the quick version first, correct answer next to each blank, followed by the full reasoning for each one.
Q
Blank
Answer
7
___ Response
Jamming Avoidance
8
___ fish
weakly electric
9
becoming ___
jammed
Q7: This mechanism is called the ___ Response A: Jamming Avoidance Location: Opening of paragraph D Explanation: The passage names this exact mechanism as the Jamming Avoidance Response, used by fish that shift frequency to avoid signal overlap.
Q8: It has been observed in ___ fish A: weakly electric Location: Opening of paragraph D Explanation: The passage specifies this behavior shows up in weakly electric fish, which is the exact species group named in the text.
Q9: Shifting frequency stops the signal from becoming ___ A: jammed Location: Middle of paragraph D Explanation: The passage states this frequency shift stops their electroreception from getting jammed or confused, and jammed is the exact word used.
Answers and Explanations of 10–13: Summary Completion
This last set traces how a ray embryo protects itself, one step at a time, straight through to the moment it goes quiet. Quick answers first, correct word next to each blank, then the full reasoning right after.
Q
Blank
Answer
10
tails in ___
constant motion
11
cuts off its ___
electric signal
12
matching a predator's ___
respiratory movements
13
harmless ___
marine life
Q10: Ray embryos keep their tails in ___ to pump water through the case A: constant motion Location: Early-middle of paragraph E Explanation: The passage says the embryo keeps its tail in constant motion so it can breathe, which is the exact phrase needed here.
Q11: If a predator is nearby, the embryo stops moving, which also cuts off its ___ A: electric signal Location: Middle of paragraph E Explanation: Once the tail stops moving, the passage says the embryo also stops transmitting its electric signal, since that motion is what produces it.
Q12: This response only triggers for signals matching a predator's ___ A: respiratory movements Location: Final line of paragraph E Explanation: The passage specifies the embryo only reacts to signals matching a predator's respiratory movements, not to any random signal nearby.
Q13: Plenty of harmless ___ passes by without setting it off A: marine life Location: Final line of paragraph E Explanation: The passage explains this selective response exists because marine life of various types often travels past, and the embryo needs to ignore those harmless signals.
HHow to Approach Electroreception IELTS Reading Questions?
This passage covers unfamiliar science terms, but the questions aren't really testing whether you already know what electroreception is. They're testing whether you can locate specific information quickly and match it precisely, which is a skill that transfers to any science-based passage you'll face later.
Each question type here rewards a slightly different approach. Here's what actually works.
This format punishes vague skimming. Read every paragraph properly first, since answers often hide inside a single specific sentence rather than a paragraph's main idea.
Paragraph G mentions both a human-benefit angle and a shark-behavior detail, so read the whole paragraph before deciding which question it answers
Don't assume a paragraph only has one usable piece of information; some paragraphs answer more than you'd expect at first glance
Underline scientific terms as you read; they usually point straight to the right paragraph
Diagram Completion
This section needs precision above everything else. A close synonym won't count, only the exact word or phrase from the passage.
Stick to the two-word limit strictly, adding an extra descriptive word costs you the mark
Read the full sentence around each blank, not just the phrase directly touching it
All three answers here sit close together in one paragraph, so read that section as a connected unit
Summary Completion
This one moves through a full sequence of events, so losing track of the order makes it harder to locate answers.
Follow the summary's structure exactly as it's written; it mirrors the passage's own sequence
Q11 and Q10 sit close together, so understanding that stretch fully often solves both faster
Match the grammar of each blank, not just the general meaning, since a wrong word form still counts as wrong
Look for Paraphrased Information
Matching information questions almost never use the passage's exact wording. "A possible use that will benefit humans" replaces "artificial electroreceptors" and "repel sharks," and that gap is intentional.
Focus on meaning over matching exact words when scanning
If a paragraph feels like a loose match rather than an obvious one, that's often the correct answer, not a wrong turn
Follow the Word Limit Carefully
Word limits are enforced strictly across all three question types in this passage.
Diagram completion allows two words maximum, summary completion allows three
Double-check spelling and grammar before finalizing any answer; a correct word spelled wrong still counts as incorrect
Put together, these habits cover exactly what this passage tests. Matching information needs full-paragraph reading, diagram completion needs precision, and summary completion needs you to follow a connected sequence rather than treating each blank as separate.
Conclusion
This passage tests something more specific than general reading comprehension, it tests whether you can track precise scientific detail across eight short paragraphs without losing accuracy. Every question type here rewards close reading over quick guessing.
A few things worth remembering before your next attempt:
Read each paragraph fully before matching it to a question, since answers often hide in specific lines, not general themes
Stick to word limits exactly, diagram and summary completion both get marked strictly
Use the full electroreception reading answers above to check your work, but only after a genuine attempt at the paraphrased passage first
What is the electroreception IELTS reading passage about?
It's an Academic Reading passage explaining how aquatic and amphibian animals sense and respond to electrical signals in water. The passage covers both passive and active electroreception, plus real examples like ray embryos, weakly electric fish, and sharks.
Which IELTS test does this passage come from?
Electroreception appears in the British Council's IELTS Reading Actual Test 03, typically as Passage 1 in the Academic Reading section, with 13 questions attached to it.
What question types appear in the electroreception reading answers section?
Three types show up here, matching information for paragraphs A through H, diagram completion focused on the ray embryo example, and summary completion covering how sharks hunt. Together, they test different reading skills within one passage.
Is the IELTS Reading Electroreception Answers passage difficult?
Most students find it moderately challenging, mainly because of the science vocabulary and how many specific details get packed into just eight paragraphs. The concepts themselves aren't complicated once explained clearly.
What's the difference between active and passive electroreception?
Passive electroreception only receives and decodes signals from other animals, with no signal production involved. Active electroreception involves an animal generating its own electric signals for things like mating, territory marking, and locating nearby objects.
What is the Jamming Avoidance Response?
It's a mechanism used by weakly electric fish, where two fish using the same signal frequency shift to different frequencies when they meet, preventing their electroreception from getting jammed or confused.
How do ray embryos use electroreception for defense?
Ray embryos stay in constant motion inside their egg cases to breathe, but stop moving the moment their electroreceptors detect a nearby predator's respiratory movements. This stops their electric signal too, helping them avoid detection.
How do sharks use electroreception to hunt?
Sharks start with smell to locate prey from a distance, then switch to electroreception once they're close enough for a precise final strike. This sense is strong enough that sharks can attack accurately even with their eyes rolled back.
Why don't sharks usually attack humans repeatedly?
Human muscle is fairly sinewy compared to softer prey like seals, which often makes sharks lose interest after one exploratory bite. Once blood enters the water though, salt intensifies the electric field, making a repeat attack more likely.
How should I prepare for the electroreception reading answers section specifically?
Focus on reading full paragraphs rather than isolated lines for the matching information questions, since answers often depend on context. For diagram and summary completion, stick strictly to the stated word limits and double check grammar before finalizing an answer.
Where can I find more science-based IELTS reading passages to practice?
upGrad's IELTS reading resources include additional science and nature-based passages that use similar mixed question formats. Practicing passages with dense factual detail, like this one, builds the exact scanning skills this passage tests.
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