GCSE Biology mAbs & plant disease questions by topic

Match each plant observation to the correct disease category.

1. (a)Purple-black spots appearing on rose leaves.[1]
2. (b)A mosaic discolouration pattern on tobacco leaves.[1]
3. (c)Recurring fever in a person bitten by mosquitoes.[1]
4. (d)Stunted growth and areas of decay on a tomato plant.[1]

Sort these plant defences into physical, chemical and mechanical.

1. (a)Name one physical defence from the list.[1]
2. (b)Name one chemical defence from the list.[1]
3. (c)Name one mechanical defence from the list.[1]
4. (d)Explain why a plant benefits from mechanical defences as well as physical ones.[3]

A student cultures bacteria on an agar plate.

1. (a)Name two nutrients the culture medium provides.[2]
2. (b)State the temperature the plate should be incubated at in school.[1]
3. (c)Give one reason for that temperature.[1]

A bacterial colony measures 12 mm across.

1. (a)Calculate the cross-sectional area of the colony. Give your answer to 3 significant figures.[2]

Match each use to the monoclonal antibody application it describes.

1. (a)A test stick that changes colour in urine within minutes.[1]
2. (b)Finding the position of a blood clot before surgery.[1]
3. (c)Delivering a drug that attaches to proteins on one kind of tumour cell.[1]
4. (d)Confirming which pathogen is growing in a plant sample.[1]

Put the steps of a school bacterial-culture practical in order, and give the reason for one of them.

1. (a)What must be done to the inoculating loop before and after use?[1]
2. (b)What is done to the agar plate before the bacteria are added?[1]
3. (c)At what temperature are school cultures incubated, and why not higher?[2]

Describe how monoclonal antibodies are produced.

1. (a)Describe the role of the lymphocyte and the tumour cell.[4]
2. (b)Explain why the final antibodies are described as "monoclonal".[2]

This question is about pregnancy testing.

1. (a)Name the hormone detected and state where it is found.[2]
2. (b)Explain how the test produces a visible result.[3]

An antibiotic is tested on a plate of bacteria. The paper disc is 6 mm wide and the clear zone around it measures 22 mm across.

1. (a)Calculate the area of the clear inhibition zone. Give your answer to 3 significant figures.[3]
2. (b)Explain what the clear zone shows about the antibiotic.[2]

Compare treating cancer with monoclonal antibodies and treating cancer with standard chemotherapy.

1. (a)State the intended advantage of the monoclonal approach.[2]
2. (b)State two limitations of monoclonal antibody treatments.[2]
3. (c)Explain why chemotherapy damages healthy cells.[2]

Two antibiotic discs were tested on the same bacterial plate. The clear zone around disc X measures 24 mm across; around disc Y it measures 16 mm across.

1. (a)Calculate the cross-sectional area of the clear zone around disc X. Give your answer to 1 decimal place.[2]
2. (b)Calculate the cross-sectional area of the clear zone around disc Y. Give your answer to 1 decimal place.[2]
3. (c)State which antibiotic is more effective against these bacteria.[1]

A greenhouse grower finds mottled, curled leaves on some tomato plants and suspects a virus.

1. (a)State two observations the grower should record while examining the plants.[2]
2. (b)Explain why looking the symptoms up in a gardening manual may not identify the disease reliably.[2]
3. (c)Describe how a monoclonal antibody test kit would give a definitive answer.[2]

Two antibiotic discs are tested on the same bacterial plate. Disc A produces a clear zone 14 mm across; disc B produces a clear zone 20 mm across.

1. (a)Calculate the area of each clear zone, to 3 significant figures.[4]
2. (b)State which antibiotic is more effective and justify your answer with the areas.[2]

Explain how a grower should investigate and respond to a suspected disease in a greenhouse crop.

1. (a)Describe the observations and identification steps.[3]
2. (b)Explain two actions the grower could take once the disease is confirmed.[3]

Explain why aseptic technique matters at every stage of the culturing practical, and what could go wrong without it.

1. (a)Write a full explanation covering sterilising, plating and incubation.[6]

A scientist measures five colonies on one plate. Their diameters are 4 mm, 6 mm, 8 mm, 6 mm and 6 mm.

1. (a)Calculate the mean diameter.[1]
2. (b)Calculate the cross-sectional area of a colony with the mean diameter. Give your answer to 3 significant figures.[2]
3. (c)Explain why the mean diameter gives a fairer picture of colony size than one measurement.[2]

Evaluate monoclonal antibodies as a medical technology.

1. (a)Present the case for and against, and reach a reasoned judgement.[6]

A colony of bacteria on an agar plate is measured every two hours after inoculation. Its diameter grows steadily: 2 mm at 0 hours, 4 mm at 2 hours, 6 mm at 4 hours and 8 mm at 6 hours.

1. (a)Calculate the mean growth rate of the colony’s diameter between 0 and 6 hours.[2]
2. (b)Predict the diameter at 8 hours if the pattern continues.[1]
3. (c)Explain two reasons why the growth would eventually slow or stop.[3]