Yellow 2 - Marvel Education

Loading question...

You are in free guest mode. Timed Practice Revision List Attempt History Progress Tracking Create a free account to unlock these tools

Prev Next

LanguageCert Practice Listening: Part 3 (Monologue) ID: #60334 Medium Yellow 2

Instructions ›

You will hear a student giving a presentation about Using bacteria as an energy source. Complete the information on the notepad. Write short answers of one to three words. You will hear the presentation twice. You have thirty seconds to look at the notepad.

Transcript:

Part 3 You will hear a science lecturer talking about the use of bacteria as an energy source. Complete the information on the notepad. Write short answers of one to three words. You will hear the person twice. You have 30 seconds to look at the notepad. My presentation today is about a field of research that could result in a new way of improving energy using bacteria. These bacteria though are unlike anything known to man. They are cyborg bacteria. I'm sure you're all familiar with the term cyborg. It's a creature or organism that is partly artificial. Until now, cyborgs have been restricted to the realm of science fiction, but no more. Scientists on the cutting edge of energy research have now created bacteria that can be artificially modified to harvest the energy in sunlight. Plants are remarkably inefficient at utilizing the sun's energy to create food sources such as starch in the process of photosynthesis. In contrast, artificial photosynthetic systems using bacteria can harness up to 80% of the energy from sunlight. Given their greater potential for converting sunlight into energy, scientists focused on bacteria, specifically Morella thermoacetica, as an energy source. In nature, these bacteria produce the chemical acetic acid from carbon dioxide and water without the need for sunlight. Acetic acid is the building block for fuels, pharmaceuticals and a range of products. It's also what we all know as vinegar, something we're more used to sprinkling on our fish and chips. It's an amazing chemical. We can also use it to create a special kind of biodegradable plastic called polyhydroxybutyrate. This is a great product because it decomposes naturally as time goes by. To boost the natural formation of acetic acid in Morella thermoacetica, scientists induced the bacteria to synthesize acetic acid under laboratory conditions. To kickstart it all, they fed the bacteria cadmium, a metal that is toxic to most organisms. Since the bacteria have a natural defense to cadmium, they convert it into crystals of cadmium sulfide, which are relatively harmless. These are then excreted onto the surface of the bacteria where they act like minute solar panels converting sunlight into energy which can be used for cellular functions like the formation of acetic acid. The whole process from growing the bacteria to adding the cadmium solution and producing artificial photosynthetic organisms takes only a couple of days. These nano solar panels perform significantly better than any man-made technology currently being used. They're not only six times more efficient than plants at converting sunlight into energy, but they're also four times more efficient than commercial solar panels, which could have a huge impact on the overall cost of energy generation. What makes this research particularly exciting is the comparative ease with which energy can be artificially harnessed from sunlight. Other techniques require expensive equipment including solid electrodes, whereas this approach only requires the bacteria to be kept outside in tanks filled with water. Since the bacteria naturally replicate themselves, it's a very simple process. The application of this research to rural areas or the developing world is potentially a game-changer. Despite the obvious advantages of this technology, researchers are the first to admit it is probably just a stepping stone to more efficient, advanced processes. What's sure though is that the findings couldn't have come at a better time. The sooner an alternative to fossil fuels is found, the better, if we're to combat climate change and rising greenhouse gas emissions caused by the burning of coal and oil. My presentation today is about a field of research that could result in a new way of improving energy using bacteria. These bacteria though are unlike anything known to man. They are cyborg bacteria. I'm sure you're all familiar with the term cyborg. It's a creature or organism that is partly artificial. Until now, cyborgs have been restricted to the realm of science fiction, but no more. Scientists on the cutting edge of energy research have now created bacteria that can be artificially modified to harvest the energy in sunlight. Plants are remarkably inefficient at utilizing the sun's energy to create food sources such as starch in the process of photosynthesis. In contrast, artificial photosynthetic systems using bacteria can harness up to 80% of the energy from sunlight. Given their greater potential for converting sunlight into energy, scientists focused on bacteria, specifically Morella thermoacetica, as an energy source. In nature, these bacteria produce the chemical acetic acid from carbon dioxide and water without the need for sunlight. Acetic acid is the building block for fuels, pharmaceuticals, and a range of products. It's also what we all know as vinegar, something we're more used to sprinkling on our fish and chips. It's an amazing chemical. We can also use it to create a special kind of biodegradable plastic called polyhydroxybutyrate. This is a great product because it decomposes naturally as time goes by. To boost the natural formation of acetic acid in Morella thermoacetica, scientists induced the bacteria to synthesize acetic acid under laboratory conditions. To kickstart it all, they fed the bacteria cadmium, a metal that is toxic to most organisms. Since the bacteria have a natural defense to cadmium, they convert it into crystals of cadmium sulfide, which are relatively harmless. These are then excreted onto the surface of the bacteria where they act like minute solar panels, converting sunlight into energy which can be used for cellular functions, like the formation of acetic acid. The whole process from growing the bacteria to adding the cadmium solution and producing artificial photosynthetic organisms takes only a couple of days. These nano solar panels perform significantly better than any man-made technology currently being used. They're not only six times more efficient than plants at converting sunlight into energy, but they're also four times more efficient than commercial solar panels, which could have a huge impact on the overall cost of energy generation. What makes this research particularly exciting is the comparative ease with which energy can be artificially harnessed from sunlight. Other techniques require expensive equipment including solid electrodes, whereas this approach only requires the bacteria to be kept outside in tanks filled with water. Since the bacteria naturally replicate themselves, it's a very simple process. The application of this research to rural areas or the developing world is potentially a game-changer. Despite the obvious advantages of this technology, researchers are the first to admit it is probably just a stepping stone to more efficient advanced processes. What's sure though is that the findings couldn't have come at a better time. The sooner an alternative to fossil fuels is found, the better, if we're to combat climate change and rising greenhouse gas emissions caused by the burning of coal and oil. That is the end of Part 3.

Using bacteria as an energy source

Scientists have learned how to create ‘cyborg’ bacteria which can use sunlight to make energy.

Bacteria are more efficient than plants at converting energy from the sun.

The bacteria Moorella thermoacetica create a chemical compound which any cook would know as (1).

Chemicals derived from these cyborg bacteria can be used to make a unique biodegradable (2).

Scientists working under (3) feed cadmium to the bacteria.

The (4) of the bacteria becomes covered in cadmium sulphide crystals which act like solar panelling.

As energy is produced more efficiently than with other methods, the total (5) of power generation might eventually reduce.

The technology is relatively simple, requiring only outdoor water (6) to hold the bacteria.

Developing countries and (7) could greatly benefit from this kind of energy production.

This could be the alternative to fossil fuels that we urgently need in order to save our planet.

Result:

Explanation

{ "questions": [ { "question": 1, "correct_answer": "vinegar", "why_correct": "The speaker says the chemical 'is also what we all know as vinegar, something we're more used to sprinkling on our fish and chips'. So the everyday name a cook would know is vinegar.", "alternative_answers": [], "common_mistakes": "Some students write 'acetic acid', but that is the scientific name, not the cook's name. This is a Paraphrase Confusion mistake.", "key_listening_points": [ "Listen for the everyday kitchen name of the chemical", "The notepad phrase 'any cook would know' matches the audio phrase 'what we all know as'" ], "tips": "When the notepad says an everyday name, listen for the simple word, not the science word.", "transcript_reference": "...In nature, these bacteria produce the chemical acetic acid from carbon dioxide and water without the need for sunlight. It's also what we all know as vinegar, something we're more used to sprinkling on our fish and chips. We can also use it to create a special kind of biodegradable plastic...." }, { "question": 2, "correct_answer": "plastic", "why_correct": "The speaker says the chemical can 'create a special kind of biodegradable plastic'. The notepad says a 'unique biodegradable ___', so the answer is plastic.", "alternative_answers": [], "common_mistakes": "Students may write the long name 'polyhydroxybutyrate', but the gap only needs the simple word plastic. This is a Paraphrase Confusion mistake.", "key_listening_points": [ "Listen for the material made from the chemical that breaks down naturally", "The notepad word 'biodegradable' matches the audio word 'biodegradable'" ], "tips": "When a hard scientific name is given, check if the gap just wants the simple everyday word.", "transcript_reference": "...It's an amazing chemical. We can also use it to create a special kind of biodegradable plastic called polyhydroxybutyrate. This is a great product because it decomposes naturally as time goes by...." }, { "question": 3, "correct_answer": "laboratory conditions", "why_correct": "The speaker says scientists made the bacteria 'synthesize acetic acid under laboratory conditions', then fed them cadmium. So they work under laboratory conditions.", "alternative_answers": [ "lab conditions" ], "common_mistakes": "Some students write only 'laboratory' and drop 'conditions', making the answer incomplete. This is a Partial Answer mistake.", "key_listening_points": [ "Listen for where the scientists do this work before feeding cadmium", "The notepad word 'under' matches the audio word 'under'" ], "tips": "The word 'under' before the gap tells you to listen for a place or setting the work happens in.", "transcript_reference": "...To boost the natural formation of acetic acid in Moorella thermoacetica, scientists induced the bacteria to synthesize acetic acid under laboratory conditions. To kickstart it all, they fed the bacteria cadmium, a metal that is toxic to most organisms. Since the bacteria have a natural defense to cadmium, they convert it into crystals of cadmium sulfide...." }, { "question": 4, "correct_answer": "surface", "why_correct": "The speaker says the crystals are 'excreted onto the surface of the bacteria where they act like minute solar panels'. So the part covered in crystals is the surface.", "alternative_answers": [], "common_mistakes": "Students may write 'crystals' because it is nearby, but the gap asks which part gets covered, which is the surface. This is a Near-Miss Distractor mistake.", "key_listening_points": [ "Listen for the part of the bacteria the crystals sit on", "The notepad phrase 'act like solar panelling' matches the audio phrase 'act like minute solar panels'" ], "tips": "Read the notepad sentence carefully to see which detail it asks for, not just any nearby word.", "transcript_reference": "...Since the bacteria have a natural defense to cadmium, they convert it into crystals of cadmium sulfide, which are relatively harmless. These are then excreted onto the surface of the bacteria where they act like minute solar panels converting sunlight into energy which can be used for cellular functions. The whole process takes only a couple of days...." }, { "question": 5, "correct_answer": "cost", "why_correct": "The speaker says the greater efficiency 'could have a huge impact on the overall cost of energy generation'. The notepad says the 'total ___ of power generation might reduce', so the answer is cost.", "alternative_answers": [], "common_mistakes": "Some students write 'energy' or 'price', but the exact word is cost. This is a Spelling and Word Form mistake if you swap it.", "key_listening_points": [ "Listen for what might get lower when energy is made more efficiently", "The notepad word 'reduce' matches the audio idea of a huge impact on cost" ], "tips": "When the notepad says something might go down, listen for money words like cost or price.", "transcript_reference": "...They're not only six times more efficient than plants at converting sunlight into energy, but they're also four times more efficient than commercial solar panels, which could have a huge impact on the overall cost of energy generation. What makes this research particularly exciting is the comparative ease...." }, { "question": 6, "correct_answer": "tanks", "why_correct": "The speaker says the method 'only requires the bacteria to be kept outside in tanks filled with water'. The notepad says 'outdoor water ___', so the answer is tanks.", "alternative_answers": [], "common_mistakes": "Students may write 'water', but that word is already in the notepad. Listen for the container word instead. This is a Paraphrase Confusion mistake.", "key_listening_points": [ "Listen for what holds the water and bacteria outdoors", "The notepad word 'outdoor' matches the audio word 'outside'" ], "tips": "Do not repeat a word already on the notepad; find the new word in the audio.", "transcript_reference": "...Other techniques require expensive equipment including solid electrodes, whereas this approach only requires the bacteria to be kept outside in tanks filled with water. Since the bacteria naturally replicate themselves, it's a very simple process...." }, { "question": 7, "correct_answer": "rural areas", "why_correct": "The speaker says the research applies to 'rural areas or the developing world'. The notepad pairs 'Developing countries and ___', so the answer is rural areas.", "alternative_answers": [], "common_mistakes": "Some students write only 'rural' and drop 'areas', making it incomplete. This is a Partial Answer mistake.", "key_listening_points": [ "Listen for the place named alongside the developing world", "The notepad phrase 'developing countries' matches the audio phrase 'the developing world'" ], "tips": "When the notepad lists two things with 'and', find the pair of them in the audio.", "transcript_reference": "...The application of this research to rural areas or the developing world is potentially a game-changer. Despite the obvious advantages of this technology, researchers are the first to admit it is probably just a stepping stone to more efficient, advanced processes...." } ] }

A.I. Explanation:

Correct Answer: vinegar
Why this is correct: The speaker says the chemical 'is also what we all know as vinegar, something we're more used to sprinkling on our fish and chips'. So the everyday name a cook would know is vinegar.
Tips: When the notepad says an everyday name, listen for the simple word, not the science word.
Correct Answer: plastic
Why this is correct: The speaker says the chemical can 'create a special kind of biodegradable plastic'. The notepad says a 'unique biodegradable ___', so the answer is plastic.
Tips: When a hard scientific name is given, check if the gap just wants the simple everyday word.
Correct Answer: laboratory conditions
Why this is correct: The speaker says scientists made the bacteria 'synthesize acetic acid under laboratory conditions', then fed them cadmium. So they work under laboratory conditions.
Tips: The word 'under' before the gap tells you to listen for a place or setting the work happens in.
Correct Answer: surface
Why this is correct: The speaker says the crystals are 'excreted onto the surface of the bacteria where they act like minute solar panels'. So the part covered in crystals is the surface.
Tips: Read the notepad sentence carefully to see which detail it asks for, not just any nearby word.
Correct Answer: cost
Why this is correct: The speaker says the greater efficiency 'could have a huge impact on the overall cost of energy generation'. The notepad says the 'total ___ of power generation might reduce', so the answer is cost.
Tips: When the notepad says something might go down, listen for money words like cost or price.
Correct Answer: tanks
Why this is correct: The speaker says the method 'only requires the bacteria to be kept outside in tanks filled with water'. The notepad says 'outdoor water ___', so the answer is tanks.
Tips: Do not repeat a word already on the notepad; find the new word in the audio.
Correct Answer: rural areas
Why this is correct: The speaker says the research applies to 'rural areas or the developing world'. The notepad pairs 'Developing countries and ___', so the answer is rural areas.
Tips: When the notepad lists two things with 'and', find the pair of them in the audio.

With a free account: Retry and compare every attempt.

Saving...