Brain Activating Reading Answers, IELTS Passage

Brain Activating Reading Answers: The passage "Brain Activating Reading Answers" explores the fascinating workings of the human brain, focusing on how neurons communicate and the development of optogenetics - a groundbreaking technique that combines genetic engineering and optics to study brain activity. 

This guide provides a detailed passage along with answers to help IELTS candidates practice effectively. The passage features common question types like True/False/Not Given, Matching Information, and Summary Completion. Practicing these formats will strengthen your ability to identify key details, improve your ability to analyze complex information quickly, and enhance your performance in the IELTS Reading test.

Free IELTS Reading Practice Tests, Cambridge Sample Test PDF

Brain Activating Reading Answers Passage

You should spend about 20 minutes on Questions 1-13, which are based on the Reading Passage below.

Brain Activating Reading Answers

1. In 1937 the great neuroscientist Sir Charles Scott Sherrington of the University of Oxford laid out what would become a classic description of the brain at work. He imagined points of light signalling the activity of nerve cells and their connections. During deep sleep, he proposed, only a few remote parts of the brain would twinkle, giving the organ the appearance of a starry night sky. But at awakening, "it is as if the Milky Way entered upon some cosmic dance," Sherrington reflected. "Swiftly the head-mass becomes an enchanted loom where millions of flashing shuttles weave a dissolving pattern, always a meaningful pattern though never an abiding one; a shifting harmony of subpatterns."

2. Although Sherrington probably did not realise it at the time, his poetic metaphor contained an important scientific idea: that of the brain revealing its inner workings optically. Understanding how neurons work together to generate thoughts and behaviour remains one of the most difficult open problems in all of biology, largely because scientists generally cannot see whole neural circuits in action. The standard approach of probing one or two neurons with electrodes reveals only tiny fragments of a much bigger puzzle, with too many pieces missing to guess the full picture. But if one could watch neurons communicate, one might be able to deduce how brain circuits are laid out and how they function. This alluring notion has inspired neuroscientists to attempt to realise Sherrington's vision.

3. Their efforts have given rise to a nascent field called optogenetics, which combines genetic engineering with optics to study specific cell types. Already investigators have succeeded in visualising the functions of various groups of neurons. Furthermore, the approach has enabled them to actually control the neurons remotely simply by toggling a light switch. These achievements raise the prospect that optogenetics might one day open the brain's circuitry to neuroscientists and perhaps even help physicians to treat certain medical disorders.

4. Enchanting the Loom Attempts to turn Sherrington's vision into reality began in earnest in the 1970s. Like digital computers, nervous systems run on electricity; neurons encode information in electrical signals, or action potentials. These impulses, which typically involve voltages less than a tenth of those of a single AA battery, induce a nerve cell to release neurotransmitter molecules that then activate or inhibit connected cells in a circuit. In an effort to make these electrical signals visible, Lawrence B. Cohen of Yale University tested a large number of fluorescent dyes for their ability to respond to voltage changes with changes in colour or intensity. He found that some dyes indeed had voltage sensitive optical properties. By staining neurons with these dyes, Cohen could observe their activity under a microscope.

5. Dyes can also reveal neural firing by reacting not to voltage changes but to the flow of specific charged atoms, or ions. When a neuron generates an action potential, membrane channels open and admit calcium ions into the cell. This calcium influx stimulates the release of neurotransmitters. In 1980 Roger Y. Tsien, now at the University of California, San Diego, began to synthesise dyes that could indicate shifts in calcium concentration by changing how brightly they fluoresce. These optical reporters have proved extraordinarily valuable, opening new windows on information processing in single neurons and small networks.

6. Synthetic dyes suffer from a serious drawback, however. Neural tissue is composed of many different cell types. Estimates suggest that the brain of a mouse, for example, houses many hundreds of types of neurons plus numerous kinds of support cells. Because interactions between specific types of neurons form the basis of neural information processing, someone who wants to understand how a particular circuit works must be able to identify and monitor the individual players and pinpoint when they turn on (fire an action potential) and off. But because synthetic dyes stain all cell types indiscriminately, it is generally impossible to trace the optical signals back to specific types of cells.

7. Optogenetics emerged from the realisation that genetic manipulation might be the key to solving his problem of indiscriminate staining. An individual's cells all contain the same genes, but that makes two cells different from each other is that different mixes of genes get turned on or off in them. Neurons that release the neurotransmitter dopamine when they fire, for instance, need the enzymatic machinery for making and packaging dopamine. The genes encoding the protein components of this machinery are thus switched on in dopamine producing (dopaminergic) neurons but stay off in other, non-dopaminergic neurons. In theory, if a biological switch that turned a dopamine-making gene on was linked to a gene encoding a dye and if the switch-and- dye unit were engineered into the cells of an animal, the animal would make the dye only in dopaminergic cells. If researchers could peer into the brains of these creatures (as is indeed possible), they could see dopaminergic cells functioning in virtual isolation from other cell types. Furthermore, they could observe these cells in the intact, living brain. Synthetic dyes cannot perform this type of magic, because their production is not controlled by genetic switches that flip to on exclusively in certain kinds of cells. The trick works only when a dye is encoded by a gene- that is, when the dye is a protein.

8. The first demonstrations that were genetically encoded a decade ago, from teams led independently by Tsien, Ehud Y. Isacoff of the University of California, Berkeley with James E. Rothman, now at Yale University. In all cases, the gene for the dye was borrowed from a luminescent marine organism, typically a jellyfish that makes the so-called green fluorescent protein Scientists tweaked the gene so that its protein product could detect and reveal the changes in voltage or calcium that underlie signalling within a cell, as well as the release of neurotransmitters that enable signalling between cells.

Brain Activating Reading Answers Sample Questions

Questions 1–5

Do the following statements agree with the information given in Reading Passage 1?
In boxes 1–5 on your answer sheet, write:

• TRUE if the statement agrees with the information

• FALSE if the statement contradicts the information

• NOT GIVEN if there is no information on this

1. Sherrington compared the brain's activity during wakefulness to a calm, starry night sky.

2. The technique of using optogenetics to study brain activity was developed by Sherrington himself.

3. Synthetic dyes can be used to detect calcium levels in neurons.

4. Dopaminergic neurons are identified by the neurotransmitter serotonin.

5. Genetically encoded dyes were first tested on human brain tissue.

Questions 6–10

The reading passage has seven paragraphs, A–H.
Which paragraph contains the following information?
Write the correct letter A–H in boxes 6–10 on your answer sheet.

6. A comparison between brain activity and an intricate pattern.

7. The origin of dyes that are sensitive to calcium levels.

8. A limitation of synthetic dyes in distinguishing different cell types.

9. The process of encoding a dye-producing gene into specific neurons.

10. The role of jellyfish proteins in the development of genetically encoded dyes.

Questions 11–13

Complete the following summary of the paragraphs of Reading Passage, using no more than three words from the Reading Passage for each answer.
Write your answers in boxes 11–13 on your answer sheet.

Sherrington's idea about the brain's activity inspired scientists to explore ways to (11)_________ the working of neurons. Early methods involved using (12)_________ that responded to voltage or calcium levels. However, a significant drawback of these dyes was their inability to distinguish between different types of cells. This problem was addressed with the development of (13)_________, which made it possible to target specific cell types.

Brain Activating Reading Answers with Explanations 

1. Sherrington compared the brain's activity during wakefulness to a calm, starry night sky.

• Answer: FALSE

• Location: Paragraph A: "During deep sleep, he proposed, only a few remote parts of the brain would twinkle, giving the organ the appearance of a starry night sky. But at awakening, 'it is as if the Milky Way entered upon some cosmic dance.'"

• Explanation: Sherrington compared brain activity during sleep to a calm starry night sky, but during wakefulness, he described it as a "cosmic dance," which contrasts with calmness.

2. The technique of using optogenetics to study brain activity was developed by Sherrington himself.

• Answer: FALSE

• Location: Paragraph C: "Although Sherrington probably did not realise it at the time, his poetic metaphor contained an important scientific idea... This alluring notion has inspired neuroscientists to attempt to realise Sherrington's vision."

• Explanation: Sherrington inspired the idea, but the actual technique of optogenetics was developed by modern neuroscientists, not Sherrington.

3. Synthetic dyes can be used to detect calcium levels in neurons.

• Answer: TRUE

• Location: Paragraph E: "In 1980 Roger Y. Tsien... began to synthesise dyes that could indicate shifts in calcium concentration by changing how brightly they fluoresce."

• Explanation: The passage clearly states that Tsien developed dyes to detect calcium concentration in neurons.

4. Dopaminergic neurons are identified by the neurotransmitter serotonin.

• Answer: FALSE

• Location: Paragraph F: "Neurons that release the neurotransmitter dopamine when they fire..."

• Explanation: Dopaminergic neurons release dopamine, not serotonin.

5. Genetically encoded dyes were first tested on human brain tissue.

• Answer: NOT GIVEN

• Location: No information provided about whether the dyes were first tested on human brain tissue.

• Explanation: The passage discusses testing on animals but does not mention human brain tissue.

6. A comparison between brain activity and an intricate pattern.

• Answer: A

• Location: Paragraph A: "Swiftly the head-mass becomes an enchanted loom where millions of flashing shuttles weave a dissolving pattern, always a meaningful pattern though never an abiding one; a shifting harmony of subpatterns."

• Explanation: Sherrington compared brain activity to a complex, shifting pattern.

7. The origin of dyes that are sensitive to calcium levels.

• Answer: E

• Location: Paragraph E: "In 1980 Roger Y. Tsien... began to synthesise dyes that could indicate shifts in calcium concentration."

• Explanation: Tsien’s work on calcium-sensitive dyes is discussed in this paragraph.

8. A limitation of synthetic dyes in distinguishing different cell types.

• Answer: F

• Location: Paragraph F: "Because synthetic dyes stain all cell types indiscriminately, it is generally impossible to trace the optical signals back to specific types of cells."

• Explanation: The limitation of synthetic dyes in targeting specific cell types is clearly mentioned.

9. The process of encoding a dye-producing gene into specific neurons.

• Answer: G

• Location: Paragraph G: "In theory, if a biological switch that turned a dopamine-making gene on was linked to a gene encoding a dye..."

• Explanation: The passage explains how encoding dye-producing genes into specific neurons works.

10. The role of jellyfish proteins in the development of genetically encoded dyes.

• Answer: H

• Location: Paragraph H: "In all cases, the gene for the dye was borrowed from a luminescent marine organism, typically a jellyfish."

• Explanation: The use of jellyfish proteins for genetically encoded dyes is discussed here.

11. Sherrington's idea about the brain's activity inspired scientists to explore ways to

• Answer: see neurons communicate

• Location: Paragraph B: "But if one could watch neurons communicate, one might be able to deduce how brain circuits are laid out and how they function."

• Explanation: The idea of seeing neurons communicate was inspired by Sherrington’s vision.

12. Early methods involved using

• Answer: fluorescent dyes

• Location: Paragraph D: "Lawrence B. Cohen of Yale University tested a large number of fluorescent dyes for their ability to respond to voltage changes."

• Explanation: Early methods involved using fluorescent dyes to detect voltage changes.

13. This problem was addressed with the development of

• Answer: genetically encoded dyes

• Location: Paragraph G: "The trick works only when a dye is encoded by a gene—that is, when the dye is a protein."

• Explanation: The development of genetically encoded dyes helped overcome the limitations of synthetic dyes.

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