day-66-ielts-listening-practice

IELTS Booster Lab Listening

Day 66 IELTS Listening Practice - Experiment Planning

Section 3 academic paraphrasing practice with three distinct voices, competing proposals, experimental controls, final decisions, quantities, settings, and dates.

Practice Instructions

1. Listen once without pausing.
2. Answer all 10 questions.
3. Check the answer key.
4. Replay the mistakes only.
5. Read the transcript after trying.
6. Write one weak point for tomorrow.

Questions 1-5

Choose the correct letter, A, B or C.

1. What is the main aim of the experiment?
   A. to compare different watering schedules
   B. to investigate how light colour affects plant growth
   C. to test three types of soil
2. Why do they decide not to use tomato plants?
   A. The seeds are too expensive.
   B. Their germination is too unpredictable.
   C. Their growth cycle is too long.
3. Which main measurement method do they agree to use?
   A. measuring plant height with a ruler
   B. calculating leaf area from photographs
   C. weighing the dried plants
4. Which experimental condition will be hardest to control?
   A. pot size
   B. water quantity
   C. temperature
5. Who will arrange the equipment bookings?
   A. Dr Bennett
   B. Rosa
   C. Callum

Questions 6-10

Complete the experiment plan. Write ONE WORD AND/OR A NUMBER for each answer.

6. Total number of basil seedlings: __________
7. Acclimatisation period: __________ days
8. Light intensity for each treatment: __________ lux
9. Background used for plant photographs: a __________ grid
10. Pilot experiment begins on: __________ October

Answer Key

1. B
2. C
3. B
4. C
5. C
6. 36
7. 4 / four
8. 800
9. white
10. 14

Distractor Explanations

• Watering and soil are controlled conditions. The variable being investigated is light colour.
• Seed price and germination are discussed, but the tomato growth cycle is the decisive problem.
• Height and dry mass are considered before leaf-area photographs are selected.
• Pot size and water can be standardised. Heat from the lamps makes temperature hardest to control.
• Rosa offers to check the lamps, but Callum receives responsibility for all equipment bookings.
• Thirty seedlings, seven days, 600 lux, a grey card, and 12 October are replaced by the final experimental details.

Transcript

Dr Bennett: Rosa and Callum, today we need to finalise your experiment plan. Your proposal mentions water, soil, and coloured lamps, but the research question must identify only one independent variable.

Rosa: We originally wanted to compare watering schedules, because that seemed easy to manage. After reading the recent studies, though, we became more interested in whether different colours of light change plant growth.

Callum: The soil will be identical in every pot, and the watering system will deliver the same amount to each plant. So our main aim is to investigate the effect of light colour on growth.

Dr Bennett: Good. State that clearly in the plan. Water and soil are controls, while light colour is the variable you are testing.

Rosa: We also need to settle the plant species. I suggested tomatoes because their leaves are large and easy to photograph.

Callum: Tomato seeds cost slightly more than basil seeds, but the difference is small. I was more concerned that their germination might be uneven.

Dr Bennett: Germination can be improved by selecting seedlings of a similar size. The serious problem is time. Tomato plants take too long to reach a useful stage, and your teaching term is only ten weeks.

Rosa: Then basil is safer. It develops quickly enough for us to observe several stages during the experiment.

Dr Bennett: Yes. Use basil rather than tomatoes because the tomato growth cycle is too long for your schedule.

Callum: For measurement, I can record the height of each plant with a ruler twice a week.

Rosa: Height alone may be misleading. A plant could be tall but have very few leaves. We could collect all the plants at the end, dry them, and compare their mass.

Dr Bennett: Dry mass is accurate, but it destroys the sample, so you could take that measurement only once. Photographs would let you calculate leaf area repeatedly without damaging the plants.

Callum: We can photograph each plant from above and use the image-analysis program to calculate the total leaf area.

Rosa: Let us use leaf area from photographs as the main measurement, with height recorded as supporting information.

Dr Bennett: Agreed. Now consider the conditions that must remain constant. The pots can all be the same size.

Callum: The automatic system can give every pot exactly 40 millilitres of water each morning, so water quantity should be stable.

Rosa: Temperature worries me. The red lamps produced noticeably more heat during our classroom demonstration.

Dr Bennett: That will be your most difficult control. Place temperature sensors beside each group and adjust the ventilation if one treatment becomes warmer than the others.

Callum: I have used those sensors before, so I can reserve them. I can also book the light meter and the overhead camera.

Rosa: I could check whether the three coloured lamps are available in the same week.

Dr Bennett: Rosa, please prepare the daily observation sheet. Callum, you will arrange all equipment bookings, including the lamps, sensors, meter, and camera. Keeping one person responsible should prevent duplicated requests.

Callum: Fine. I will submit the booking form this afternoon.

Rosa: How many seedlings should we order? I calculated that 30 plants would give us ten under each light treatment.

Dr Bennett: Ten per group leaves little protection if some plants fail. Use 12 plants in each of the three treatments. That means you need 36 basil seedlings altogether.

Callum: We should allow the seedlings to adjust to the laboratory before changing the lights. Would one week be suitable?

Dr Bennett: A full week would reduce the experimental period unnecessarily. Four days is enough for acclimatisation, provided the plants receive normal white light during that time.

Rosa: After those four days, we divide them into red, blue, and white-light groups.

Callum: What intensity should the lamps produce? During the demonstration, 600 lux seemed bright enough.

Dr Bennett: Six hundred was suitable for observation, not sustained growth. Set every treatment to 800 lux, and check the reading at leaf level rather than beside the lamp.

Rosa: Eight hundred lux for all three groups. I will add that to the observation sheet.

Callum: For the photographs, I thought we could place a grey card beneath each pot. That would make the green leaves easy to distinguish.

Dr Bennett: The software can separate the leaves from either grey or white. A white grid is more useful because the grid provides a scale if the camera height changes slightly.

Rosa: Then every plant will be photographed against a white grid from the same overhead position.

Callum: We planned to start the pilot on 12 October. Does that still fit the laboratory schedule?

Dr Bennett: The preparation room is being cleaned on the twelfth, so no plant work can take place then. The room is free two days later.

Rosa: Shall we confirm 14 October for the pilot experiment?

Dr Bennett: Yes. Begin the pilot on 14 October. Test the camera position, light readings, watering system, and temperature sensors before you bring in all 36 seedlings.

Callum: I will book the equipment for the fourteenth and send both of you the confirmation.

Rosa: I will finish the observation sheet and label the white grids. We now have the plant species, measurement method, controls, sample size, settings, and pilot date.

Dr Bennett: Good. Revise the written plan so every proposal is replaced by the final decision we made today.

Mistake-Review Point

Wait for the final decision after each proposal; an idea mentioned first may be rejected or modified.