Cardinal Newman College
A-level Biology (7401/7402) Name:
Class:
Energy and ecosystems, nutrient
recycling and succession PPQs
Time: 126
Marks: 109
Comments: Note that the questions come in 4 headed sections.
Page 1
, Cardinal Newman College
3.5.3 ENERGY AND ECOSYSTEMS
Q1.Yield can be determined by measuring the dry mass of plants.
(a) Suggest how you could determine the dry mass of a sample of plant material.
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(2)
(b) What is the advantage of using dry mass and not fresh mass to compare the yield of
plants?
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.........................................................................................................................
.........................................................................................................................
.........................................................................................................................
(2)
(Total 4 marks)
Q2. Scientists measured the mean temperature in a field each month between March and
October. The table shows their results.
Month Mean temperature /°C
March 9
April 11
May 14
June 17
July 20
August 18
September 16
October 14
Page 2
, Cardinal Newman College
(a) The gross productivity of the plants in the field was highest in July.
Use the data in the table to explain why.
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......................................................................................................................
......................................................................................................................
(2)
(b) (i) Give the equation that links gross productivity and net productivity.
.............................................................................................................
(1)
(ii) The net productivity of the plants in the field was higher in August than in July.
Use the equation in part (b)(i) and your knowledge of photosynthesis and
respiration to suggest why.
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.............................................................................................................
.............................................................................................................
.............................................................................................................
(2)
(c) A horse was kept in the field from March to October. During the summer months, the
horse was able to eat more than it needed to meet its minimum daily requirements.
Suggest how the horse used the extra nutrients absorbed.
......................................................................................................................
......................................................................................................................
......................................................................................................................
(1)
Page 3
A-level Biology (7401/7402) Name:
Class:
Energy and ecosystems, nutrient
recycling and succession PPQs
Time: 126
Marks: 109
Comments: Note that the questions come in 4 headed sections.
Page 1
, Cardinal Newman College
3.5.3 ENERGY AND ECOSYSTEMS
Q1.Yield can be determined by measuring the dry mass of plants.
(a) Suggest how you could determine the dry mass of a sample of plant material.
.........................................................................................................................
.........................................................................................................................
.........................................................................................................................
.........................................................................................................................
(2)
(b) What is the advantage of using dry mass and not fresh mass to compare the yield of
plants?
.........................................................................................................................
.........................................................................................................................
.........................................................................................................................
.........................................................................................................................
(2)
(Total 4 marks)
Q2. Scientists measured the mean temperature in a field each month between March and
October. The table shows their results.
Month Mean temperature /°C
March 9
April 11
May 14
June 17
July 20
August 18
September 16
October 14
Page 2
, Cardinal Newman College
(a) The gross productivity of the plants in the field was highest in July.
Use the data in the table to explain why.
......................................................................................................................
......................................................................................................................
......................................................................................................................
......................................................................................................................
......................................................................................................................
(2)
(b) (i) Give the equation that links gross productivity and net productivity.
.............................................................................................................
(1)
(ii) The net productivity of the plants in the field was higher in August than in July.
Use the equation in part (b)(i) and your knowledge of photosynthesis and
respiration to suggest why.
.............................................................................................................
.............................................................................................................
.............................................................................................................
.............................................................................................................
.............................................................................................................
(2)
(c) A horse was kept in the field from March to October. During the summer months, the
horse was able to eat more than it needed to meet its minimum daily requirements.
Suggest how the horse used the extra nutrients absorbed.
......................................................................................................................
......................................................................................................................
......................................................................................................................
(1)
Page 3
