A nursery produces 240 clones from one disease-resistant plant using meristem tissue. All are planted in one field.
.1
Explain how meristem cells produce complete plants.
[2 marks].2
Evaluate planting only these clones in one field.
[3 marks]AQA GCSE Combined Science June 2025 Biology Paper 1H
5 questions on this paper's topics
25:001 of 5
A patient with influenza asks for antibiotics and takes a painkiller to reduce fever.
.1
Explain why antibiotics do not cure influenza and why the painkiller may still help.
[2 marks].2
Explain why developing drugs against viruses can be difficult.
[2 marks]Root cells absorb nitrate from a solution with a lower nitrate concentration than the cells. A poison stops respiration without damaging the cell membrane.
.1
Explain why nitrate uptake decreases.
[3 marks].2
Explain why water can still cross the membrane.
[2 marks]During exercise a patient's heart rate is 120 beats/min and each side pumps 110 cm³ per beat. Cardiac output is the volume pumped by one side per minute.
.1
Calculate cardiac output in dm³/min.
[2 marks].2
Explain how increased cardiac output supports exercise.
[3 marks]A potometer reservoir initially contains 24.0 cm³ of water. After 90 minutes it contains 17.7 cm³. A sealed control loses no water. The student claims that all 6.3 cm³ must have evaporated from the leaves.
.1
Calculate the shoot's mean uptake rate.
[2 marks].2
Evaluate the claim about evaporation.
[2 marks]