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B7: Quiz 4 – Answers
B7: Quiz 4 – Answers
1)
a) Grass
b) Rabbits, mice and grasshoppers
c) Fox
d) Any 2 from the following:
grass –> rabbit –> fox
grass –> mice –> bird –> fox
grass –> grasshopper–> bird –> fox
e) If the population of rabbits decreased, there would be more grass (food) available for the mice and grasshoppers, which would cause the population of mice and grasshoppers to increase. If the population of mice and grasshoppers increased, there would be more food available for the bird, so the population of birds would increase.
Foxes eat rabbits and birds. The population of rabbits has decreased and the population of birds has increased. This means that the effect on the population of foxes is uncertain.
2)
a)
i) Lion
ii) Gazelle
b)
i) The population of lions increased between 3 and 8 years. This is because the population of gazelles increased, which meant that there was more food available for the lions, so the population of lions increased.
ii) The population of gazelles decreased between 6 and 12 years. This is because the population of lions increased, which resulted in more gazelles being eaten by lions, so the population of gazelles decreased.
a) Grass
b) Rabbits, mice and grasshoppers
c) Fox
d) Any 2 from the following:
grass –> rabbit –> fox
grass –> mice –> bird –> fox
grass –> grasshopper–> bird –> fox
e) If the population of rabbits decreased, there would be more grass (food) available for the mice and grasshoppers, which would cause the population of mice and grasshoppers to increase. If the population of mice and grasshoppers increased, there would be more food available for the bird, so the population of birds would increase.
Foxes eat rabbits and birds. The population of rabbits has decreased and the population of birds has increased. This means that the effect on the population of foxes is uncertain.
2)
a)
i) Lion
ii) Gazelle
b)
i) The population of lions increased between 3 and 8 years. This is because the population of gazelles increased, which meant that there was more food available for the lions, so the population of lions increased.
ii) The population of gazelles decreased between 6 and 12 years. This is because the population of lions increased, which resulted in more gazelles being eaten by lions, so the population of gazelles decreased.
Questions
1) We have the food web below.
1) We have the food web below.
a) Who is the producer in the food web?
b) Who are the three primary consumers?
c) Which consumer is both a secondary consumer and a tertiary consumer?
d) Write down 2 different food chains from the food web.
e) There is a disease that causes the population of rabbits to decrease. What effect will this have on the populations of all of the other organisms in the food web.
2) We have the food chain below.
b) Who are the three primary consumers?
c) Which consumer is both a secondary consumer and a tertiary consumer?
d) Write down 2 different food chains from the food web.
e) There is a disease that causes the population of rabbits to decrease. What effect will this have on the populations of all of the other organisms in the food web.
2) We have the food chain below.
a) The lions eat the gazelles.
i) Who is the predator?
ii) Who is the prey?
b) The graph below shows how the populations of gazelles and lions changes over time.
i) Who is the predator?
ii) Who is the prey?
b) The graph below shows how the populations of gazelles and lions changes over time.
i) Describe and explain the population change for lions between 3 and 8 years.
ii) Describe and explain the population change for gazelles between 6 and 12 years.
ii) Describe and explain the population change for gazelles between 6 and 12 years.