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 →rabbit →fox →fleas

  • 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
1 mark

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

Calculate how much energy the plant plankton received.

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

How did you do?

2c
1 mark

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

How did you do?

3
4 marks

The following represents a food chain from a Scottish river.

pond weed →tadpole →water beetle →pike

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

How did you do?

4
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 →squirrel →fox

  • 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