National 5BiologySQAExam QuestionsUnit 3: Life on EarthEnergy in ecosystems

Energy in ecosystems (SQA National 5 Biology): Exam Questions

Exam code: X807 75

11 mins6 questions
1
1 mark

The diagrams represent pyramids of numbers.

Which pyramid represents the following food chain?

grass rightwards arrowrabbit rightwards arrowfox rightwards arrowfleas

  • Simple geometric design with three horizontal rectangles stacked vertically, separated by two vertical lines, forming a symmetrical structure.
  • A geometric shape showing three stacked rectangles of varying sizes, aligned vertically, with the middle one being the widest, resembling a tiered diagram.
  • Stack of four increasingly smaller rectangular blocks, centred and layered vertically, resembling a simplified pyramid or tiered structure.
  • Three horizontal rectangles stacked in a pyramid shape, with the top one larger, connected by vertical lines to the middle and bottom rectangles.

Choose your answer

2a
1 mark

The diagram shows the transfer of energy through a food chain in an ecosystem.
The numbers represent the energy in the different populations.

Pyramid chart depicting an ecosystem: Plant plankton 42,000 units, Minnow 4,000 units, Trout 380 units, Osprey 76 units, from bottom to top.

Name the type of diagram shown.

How did you do?

2b
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1 mark

5% of light reaching the plant plankton is converted into new plant material.

Calculate how much energy the plant plankton received.

...............................units

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2c
1 mark

State one way in which energy can be lost from a food chain.

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3
4 marks

The following represents a food chain from a Scottish river.

pond weed rightwards arrowtadpole rightwards arrowwater beetle rightwards arrowpike

Describe the role of pond weed in this food chain and explain what happens to the energy at each level in this food chain.

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4
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1 mark

The diagram represents a pyramid of numbers within an ecosystem.

A triangle divided into four sections with the numbers 4, 65, 4029, and 13 508 from top to bottom.

Identify the total number of consumers.

  • 4

  • 4029

  • 4098

  • 17 606

Choose your answer

5
1 mark

Identify the pyramid of energy that would represent the following food chain.

Oak tree rightwards arrowsquirrel rightwards arrowfox

  • Grey three-tiered rectangle stack with black outlines, each tier smaller than the one below, forming a pyramidal shape.
  • Diagram showing three grey rectangles forming a cross shape, with the largest rectangle in the centre and smaller rectangles on top and bottom.
  • A simple geometric diagram showing three grey rectangles, one stacked atop another, forming a T-shape with black outlines on a white background.
  • Simple grey T-shaped graphic composed of three horizontal rectangles of varying widths stacked vertically, with the smallest at the bottom.

Choose your answer

6
1 mark

An investigation was carried out to measure the change in body mass in a population of adult locusts kept in a tank at 25 °C. The percentage of food converted into body mass was recorded over a three-week period.

The reliability of the results could be improved by:

  • decreasing the length of time of the investigation

  • increasing the mass of food given to the locusts

  • increasing the number of locusts in the tank

  • decreasing the temperature in the tank

Choose your answer