IELTS Secrets - EXPLANATION

READING 1: BIOLUMINESCENCE

Q1: Complete the table below.

Answer: bacteria
Key word(s): "some animals and plants," "get this from bacteria"
Cited Sentence: "Others get this from bacteria which live inside their bodies, and which produce light all the time."
Explanation: The text mentions that some organisms acquire luciferin from bacteria that live inside their bodies, making "bacteria" the correct answer.

Q2: Complete the table below.

Answer: luciferase
Key word(s): "works with luciferin"
Cited Sentence: "When activated by an enzyme called luciferase, the resulting chemical reaction creates light."
Explanation: The sentence explicitly states that luciferase activates luciferin to produce light, making "luciferase" the correct answer.

Q3: Complete the table below.

Answer: habitat
Key word(s): "depends on the habitat"
Cited Sentence: "The colour of the light emitted by bioluminescent organisms varies greatly, depending on the habitat of the organism producing the light."
Explanation: The sentence directly tells us that the colour of the light is related to the organism’s habitat, making "habitat" the correct answer.

Q4: Complete the table below.

Answer: (private) communication
Key word(s): "private communication"
Cited Sentence: "One use of this red glow is to create a means of private communication between male and female dragonfish that goes unnoticed by other fish."
Explanation: The text describes the purpose of red bioluminescence in dragonfish as creating private communication between mates, making "communication" the correct answer.

Q5: Complete the table below.

Answer: yellow spectrum
Key word(s): "yellow spectrum"
Cited Sentence: "Most often, however, land-based creatures use blue-green bioluminescence as in the ocean, but in the yellow spectrum."
Explanation: The sentence notes that land-based creatures use a yellow spectrum for bioluminescence, making "yellow spectrum" the correct answer.

Q6: Complete each sentence with the correct ending.

Answer: H
Key word(s): "lured by their glowing light"
Cited Sentence: "Click beetles crowd on termite mounds after sunset, and anything that is lured by their glowing light will soon become sustenance."
Explanation: The sentence explains that the glowing light of click beetles attracts prey, which aligns with option H ("attract food to their light").

Q7: Complete each sentence with the correct ending.

Answer: D
Key word(s): "use bioluminescence to find their next meal"
Cited Sentence: "Dragonfish, for example, use their red light to see what is in their immediate environment and locate their next meal."
Explanation: The text describes how dragonfish use bioluminescence to find prey, making "find prey in a dark environment" the correct answer.

Q8: Complete each sentence with the correct ending.

Answer: J
Key word(s): "appear to be sunlight travelling through the water"
Cited Sentence: "Hatchet fish, have developed bioluminescence to eliminate this tell-tale, using a technique known as 'counterillumination'. They project light from the underside of their form so that they appear to be sunlight travelling through the water, effectively disappearing from the gaze of predators looking up from below."
Explanation: The sentence describes how hatchet fish use bioluminescence to avoid being seen by predators, which matches "hide from their enemies."

Q9: Complete each sentence with the correct ending.

Answer: C
Key word(s): "flash brightly to startle any fish"
Cited Sentence: "Some bioluminescent squid flash brightly to startle any fish that come too close, buying the necessary time to swim to safety."
Explanation: The sentence describes how some squid use their light to startle predators and escape, aligning with "escape from potential predators."

Q10: Complete each sentence with the correct ending.

Answer: A
Key word(s): "light up to tell other animals that they are toxic"
Cited Sentence: "Insect larvae, commonly referred to as glow-worms, light up to tell other animals that they are toxic and to be avoided."
Explanation: The text states that glow-worms use bioluminescence as a warning signal, which matches "warn predators that they are poisonous."

Q11: Complete each sentence with the correct ending.

Answer: F
Key word(s): "flash to indicate that they are looking for a mate"
Cited Sentence: "Fireflies flash to indicate that they are looking for a mate."
Explanation: The sentence explains that fireflies use their bioluminescence to attract mates, aligning with "attract potential mates."

Q12: Complete each sentence with the correct ending.

Answer: G
Key word(s): "glowing to attract insects with the ultimate goal of broadcasting their colonies"
Cited Sentence: "Fungi such as some toadstools or mushrooms use bioluminescence to disperse their spores, glowing to attract insects with the ultimate goal of broadcasting their colonies far and wide."
Explanation: The text explains that mushrooms use their glow to attract insects and spread spores, which matches "enable the spread of reproductive cells."

Q13: Choose the correct letter.

Answer: B
Key word(s): "overview of the manufacture and uses of bioluminescence"
Cited Sentence: The entire passage describes the different uses and functions of bioluminescence in various organisms.
Explanation: The passage provides an overview of the ways bioluminescence is used in nature (for communication, hunting, and defense), which aligns best with answer B: "to give an overview of the manufacture and uses of bioluminescence in organisms."

READING 2: ANCIENT EGYPTIANS – FOUNDING FATHERS OF PHARMACOLOGY?

Q14: What do we learn in the first paragraph of this text?
Answer: C
Key word(s): ancient Egyptians, drug treatments, Greeks, pharmacopoeia
Cited Sentence: "Recent evidence has emerged, however, that suggests that ancient Egyptian studies of science-based medicine and pharmacology preceded the Greeks and, in particular, the Greek 'De Materia Medica', a written list of 600 drugs and their uses which has been dated to 50 CE..."
Explanation: The first paragraph explains that the Egyptians studied drug treatments before the Greeks and possibly even contributed to the creation of the first pharmacopoeia, a medical reference that the Greeks later produced.

Q15: Which of the following is NOT mentioned as evidence of Egyptian medical skills?
Answer: D
Key word(s): evidence, Egyptian medical skills, artefacts
Cited Sentence: "A plethora of Egyptian artefacts, including surgical instruments such as scalpels and pliers, prosthetic great toes on at least two mummies, and mummified remains revealing the successful treatment of serious injuries, all point to the substantial medical knowledge of these ancient people."
Explanation: The text lists surgical tools, prosthetics, and mummified remains as evidence but does not mention anything about jawbones with extracted teeth, making option D the correct answer.

Q16: Why is it difficult to study written Egyptian pharmaceutical records?
Answer: B
Key word(s): Egyptian pharmaceutical records, difficulty, translations, words
Cited Sentence: "Some of the words in the medical papyrus texts appear only in lists and not in complete sentences, and often in one document only."
Explanation: The difficulty lies in the fact that many words are found only in lists or isolated documents, making it challenging to translate them accurately. Thus, option B is the correct choice.

Q17: Campbell’s study aimed to make clearer ___________ of Egyptian drug ingredients to find out how effective their knowledge had been.
Answer: identification
Key word(s): study, aim, Egyptian drug ingredients, effectiveness
Cited Sentence: "Campbell’s study aimed to make clearer the identification of Egyptian drug ingredients to find out how effective their knowledge had been."
Explanation: The word "identification" directly follows the mention of the study's aim in the text.

Q18: She used current knowledge of ___________ to check that the ingredients listed would have been available.
Answer: (Egyptian) flora
Key word(s): current knowledge, check, ingredients, available
Cited Sentence: "Campbell began by cross-checking that the plants in the prescriptions actually grew or were traded in Egypt when the parchments were written."
Explanation: The text mentions "Egyptian flora" as a basis for cross-referencing the plants used in the prescriptions to ensure they were available at the time.

Q19: She also examined key documents from the period when ___________ was first used.
Answer: precise measurement
Key word(s): key documents, period, precise measurement
Cited Sentence: "She then set out to study four vital parchments covering prescriptions dating from circa 1850 BCE to 1200 BCE, when precise measurement was first used."
Explanation: The text clearly states that Campbell examined documents from a period when precise measurement was introduced.

Q20: These documents listed ingredients, their preparation and administration, and the ___________.
Answer: appropriate dosage
Key word(s): documents, ingredients, preparation, administration, dosage
Cited Sentence: "These medical records all contained instructions which followed a systematic recording of the list of constituents and the means by which these were assembled and mixed for use, how they were dispensed, and the appropriate dosage."
Explanation: The text explicitly mentions that the documents also listed the "appropriate dosage" for the prescriptions.

Q21: She wanted to validate or disprove each recipe; a few ingredients, e.g. ___________, had clearly been incorrectly translated.
Answer: aniseed
Key word(s): validate, disprove, recipe, ingredients, incorrectly translated
Cited Sentence: "Some constituents, such as aniseed, were included in the translations but would not have worked as prescribed..."
Explanation: The example of "aniseed" is used to illustrate ingredients that were incorrectly translated.

Q22: Results of the Study – Identification of ingredients
• All or most of the ingredients for the majority of remedies have now been verified
• More than half the remedies would have had some ___________
Answer: therapeutic value
Key word(s): results, remedies, therapeutic value
Cited Sentence: "Over sixty per cent of the prescriptions would have been of therapeutic value, at least to some extent..."
Explanation: The text clearly states that more than half of the remedies had therapeutic value, supporting this answer.

Q23: Many Egyptian ingredients are still used, though some are now in ___________
Answer: synthetic form
Key word(s): Egyptian ingredients, still used, synthetic form
Cited Sentence: "After consulting a 1977 pharmacopoeia, Campbell found that sixty-two per cent of the verified constituents were still in use in the 70s; in fact, many are common today, albeit in synthetic form."
Explanation: The text mentions that many of the ingredients are still in use today, though in synthetic form.

Q24: Extraction methods included the use of a suitable medium according to the ___________ of the drug
Answer: solubility
Key word(s): extraction methods, suitable medium, solubility
Cited Sentence: "Campbell found that over sixty per cent of the ancient remedies complied with the 1973 British Pharmaceutical Codex in all but one area; Egyptians did not know of the need for sterility protocols, although they did value cleanliness in their medical professionals."
Explanation: The text discusses the use of appropriate extraction methods based on the solubility of the drug, making "solubility" the correct answer.

Q25: Every treatment obeyed the current rules for use, with the exception of ___________
Answer: sterility protocols
Key word(s): treatments, current rules, exception, sterility protocols
Cited Sentence: "Campbell found that over sixty per cent of the ancient remedies complied with the 1973 British Pharmaceutical Codex in all but one area; Egyptians did not know of the need for sterility protocols..."
Explanation: The text mentions that the only exception to the compliance with current rules was the lack of sterility protocols.

Q26: Establishing the ___________ of Egyptian drugs
Answer: efficacy
Key word(s): establishing, Egyptian drugs, efficacy
Cited Sentence: "The final test of Egyptian pharmacology was to discover the efficacy of the remedies for the problems they were prescribed for."
Explanation: The text mentions the "efficacy" as the final test to assess the effectiveness of Egyptian drugs.

Q27: Yet, over half of their remedies would have worked as well as ___________
Answer: contemporary prescriptions
Key word(s): remedies, worked, contemporary prescriptions
Cited Sentence: "Despite the fact that Egyptians were primarily treating symptoms, lacking precise knowledge of the root cause of most medical ailments, she found that even down to the exact dosage, sixty-four per cent of those prescriptions had curative value comparable to contemporary prescriptions."
Explanation: The text compares the efficacy of Egyptian remedies with "contemporary prescriptions," indicating their comparable effectiveness.

READING 3: HAPPINESS – IT'S ALL IN YOUR HEAD

Q28: Section A
Answer: vi
Key word(s): awareness of happiness, evolutionary advantage, struggle to achieve
Cited Sentence: "Nonetheless, most humans are engaged in a constant struggle to achieve, and the urge to maximise and prolong happiness is one of our primary motivations for doing so."
Explanation: Section A discusses how humans are aware of their potential happiness and unhappiness, which relates to the evolutionary advantage and the struggle to achieve happiness. This matches the heading about the awareness of happiness.

Q29: Section B
Answer: i
Key word(s): brain, experiment, positive and negative emotions
Cited Sentence: "To search for the specific areas of the brain responsible for happiness, more than a hundred students from the University of Wisconsin were recruited for an experiment."
Explanation: Section B outlines an experiment to locate the areas of the brain responsible for happiness, which fits the heading about deepening understanding through research.

Q30: Section C
Answer: viii
Key word(s): pleasure, liking, brain regions
Cited Sentence: "In experiments, these hotspots can be stimulated with tiny injections of drugs to produce a doubling or tripling of the sensation of liking."
Explanation: Section C discusses different parts of the brain that respond to pleasure and liking, fitting with the heading differentiating pleasure responses in the brain.

Q31: Section D
Answer: v
Key word(s): addicts, craving, reward, dissociation
Cited Sentence: "The fact that these responses are different and occur in different parts of the brain may help to explain why addicts of all kinds may crave a reward without necessarily liking that reward."
Explanation: Section D focuses on the effects of addiction, where craving a reward does not necessarily lead to liking it, linking to the heading regarding deficiencies in neural mechanisms for happiness.

Q32: Section E
Answer: ii
Key word(s): pleasures, social interactions, complex enjoyment
Cited Sentence: "Further, there are the broader pleasures that come from social interactions which are essential to humans: they run from the heightened sensory responses to touch from loved ones to the more abstract appreciation of reciprocity, social rewards and valued relationships."
Explanation: Section E addresses more complex pleasures, including social interactions, and explores broader pleasures, which ties to the challenges in understanding happiness.

Q33: According to Section A, what is one reason why people set goals?
Answer: D
Key word(s): set goals, survival, procreate
Cited Sentence: "The need to survive and procreate is at the root of adaptive behaviours for all life forms."
Explanation: Section A mentions survival and procreation as fundamental motivators, which influences goal-setting, so the answer is about seeking pleasurable sensations as a goal in the context of survival.

Q34: What do we learn about happiness in Section B?
Answer: C
Key word(s): happiness, duration, brain
Cited Sentence: "The experiment found that one small area of the brain appears to be the source of the prolongation of positive feelings."
Explanation: Section B reveals that one brain area is responsible for the extended duration of happiness, which supports the answer that a part of the brain makes us feel happy for longer.

Q35: There are fewer 'pleasure' sites in the brain than 'liking' ones.
Answer: FALSE
Key word(s): pleasure sites, liking sites, brain
Cited Sentence: "However, there are very few mechanisms that cause pleasure reactions in the form of a response we usually label as 'liking'."
Explanation: Section C indicates that there are fewer 'liking' mechanisms in the brain, not 'pleasure' ones, so the statement is false.

Q36: 'Liking' is usually a weaker response than 'pleasure'.
Answer: NOT GIVEN
Key word(s): liking, pleasure, strength
Cited Sentence: No specific sentence in Section C or elsewhere directly compares the strength of liking and pleasure.
Explanation: The comparison between 'liking' and 'pleasure' is not discussed in terms of strength, so this information is not provided.

Q37: Some people suffer from a disconnect between the different brain responses to pleasurable stimuli.
Answer: TRUE
Key word(s): disconnect, brain responses, pleasurable stimuli
Cited Sentence: "In extreme circumstances, an addict may want something that is fully recognised consciously as being undesirable – the dissociation occurs because of the lack of integration of the mental faculties..."
Explanation: This statement is true, as Section D describes a disconnect between the brain's responses, particularly in addicts who may crave rewards but not like them.

Q38: People with depression can suffer from disturbances to their sense of taste.
Answer: NOT GIVEN
Key word(s): depression, taste, disturbances
Cited Sentence: "In animals with such damage, even the delight in sugary tastes can be lost so that they react as if the substance is bitter or otherwise foul-tasting."
Explanation: While the text mentions that animals with brain damage lose the ability to enjoy sugary tastes, there is no direct information about humans with depression suffering from taste disturbances.

Q39: Depression may be correlated with an inability to remember, or look forward to, pleasure.
Answer: TRUE
Key word(s): depression, memory, pleasure
Cited Sentence: "In some cases there may be a kind of automatic appreciation of fundamental pleasures, but the more developed thought processes that normally arise, such as reflection on the enjoyment or anticipation of renewed pleasure, may no longer be available to some people."
Explanation: Section D explains that people with depression may lose the ability to anticipate or reflect on pleasures, linking depression to a lack of memory and future enjoyment.

Q40: We now understand the brain chemistry that controls complex forms of pleasure.
Answer: FALSE
Key word(s): brain chemistry, complex pleasure
Cited Sentence: "there are still significant gaps in our appreciation of the processes behind more sophisticated levels of enjoyment."
Explanation: Section E mentions that there are still gaps in understanding the brain processes behind more complex forms of pleasure, so the statement is false.