4b Feeding Relationships

Question 1

What is a herbivore?

Answer 1

Animal that only eats plants - hedgehog, sheep, rabbit

Question 2

What is a carnivore?

Answer 2

Animal that only eats other animals - tiger, lion

Question 3

What is an omnivore?

Answer 3

Animal that eats both plants and animals - human, bear

Question 4

What is a predator?

Answer 4

An animal that hunts other animals - shark

Question 5

What is prey?

Answer 5

An animal that is food for another animal - squirrel

Question 6

What are scavengers?

Answer 6

• When an animal searches for food
• Eats stuff that’s already been killed - eagle, hyena

Question 7

What is a trophic level?

Answer 7

• Each level of a food chain is called a trophic level

Question 8

What is the first trophic level?

Answer 8

• Producer
• Producers convert light energy from the sun into chemical energy stored in their tissues

Question 9

What is the second trophic level?

Answer 9

• Primary Consumer
• Primary consumers eat producers, transferring energy into their tissues

Question 10

What is the third trophic level?

Answer 10

• Secondary Consumer
• Secondary consumers eat primary consumers, transferring energy into their tissues

Question 11

What is the fourth trophic level?

Answer 11

• Tertiary Consumers
• Tertiary consumers eat secondary consumers, transferring energy into their tissues

Question 12

What is a decomposer?

Answer 12

• At any trophic level organisms produce waste, or may die; the energy in waste or dead matter is then transferred to decomposers

Question 13

What is a pyramid of numbers?

Answer 13

• The size of each stage of the pyramid represents the number of organisms feeding at that level of the food chain (trophic level)

Question 14

What is biomass?

Answer 14

The dry mass of living material

Question 15

What is a pyramid of biomass?

Answer 15

• Each bar represents the mass of living material at each trophic level of the food chain
• These are usually a pyramid shape

Question 16

What do the arrows in a food chain represent?

Answer 16

• Simply it shows ‘the grass eaten by the vole’
• More scientifically they show the flow or transfer of energy through a food chain

Question 17

What is a pyramid of energy?

Answer 17

• This relates to the energy at each tropic level that gets transferred
• Measured in kj/ha/yr
  ha = a hectare = 10,000m2

Question 18

How is data collected in a pyramid of numbers?

Answer 18

• Observe and count the number of organisms at each trophic level at a point in time

Question 19

Is a pyramid of numbers a pyramid shape?

Answer 19

• Often not a pyramid shape eg. if producer is a tree

Question 20

What are advantages of a pyramid of numbers?

Answer 20

• No organisms are killed in data collection
• Simplest for data collection
• Gives a ‘snap-shot’ of the number of organisms at a particular time. It can therefore be used to compare population numbers at different times in the year

Question 21

What are the disadvantages of Pyramid of numbers?

Answer 21

• The numbers of each organism could be too great to show accurately in the diagram
• Provides a ‘snap-shot’ so should not be used to generalise across other times of the year

Question 22

How is data collected in a pyramid of biomass?

Answer 22

• Kill one organism at each trophic level; dry the organism and weigh the dry mass. Multiply the biomass by the number of organisms at each trophic level

Question 23

Is a pyramid of biomass a pyramid shape?

Answer 23

• Usually a pyramid shape

Question 24

What are the advantages of a pyramid of biomass?

Answer 24

• More accurate indication of how much energy is passed on at each trophic level than pyramid of number

Question 25

What are the disadvantages of a pyramid of biomass?

Answer 25

- Organisms must be killed - Provides a 'snap-shot' so should not be used to generalise across other times of the year - Provides an indication of how much energy is stored at each level but not a precise value as some of the biomass can't be used for energy eg. indigestible materials

Question 26

How is data collected in a pyramid of energy?

Answer 26

- Use a colorimeter to find the energy for each organism and multiply by the number of organisms at that trophic level - Calculate the energy for a particular area over a period of time eg. a year

Question 27

Is a pyramid of biomass a pyramid shape?

Answer 27

- Always a pyramid shape as energy is lost as you go up a food chain

Question 28

What are the advantages of a pyramid of energy?

Answer 28

- The exact amount of energy at each trophic level is calculated - Gives information over a time period

Question 29

What are the disadvantages of a pyramid of energy?

Answer 29

- Organisms must be killed - A colorimeter is required - Most complicated method for data collection. The number of organisms at each trophic level must be calculated over a period of time eg. a year