Topic 7 Assessment Booklet
Marks = 167 Time Allowed 222 minutes
Q1.
(a) What is a gene pool?
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___________________________________________________________________
(1)
(b) Lord Howe Island in the Tasman Sea possesses two species of palm tree which
have arisen via sympatric speciation. The two species diverged from each other
after the island was formed 6.5 million years ago. The flowering times of the two
species are different.
Using this information, suggest how these two species of palm tree arose by
sympatric speciation.
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___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
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___________________________________________________________________
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(5)
(Total 6 marks)
Q2.
Impala and wildebeest are species of herbivore that live in large groups. They spend most
of their time feeding with their heads near the ground.
Scientists investigated the relationship between the number of predators in an area and
the mean proportion of time these herbivores spent with their heads up, looking around
rather than feeding. They obtained data from groups of impala and wildebeest in two
areas. In one area there were few predators and in the other area there were many
predators.
Page 1 of 46
,The graph shows their results. The bars show standard deviations.
(a) The scientists observed both groups of animals for 75 hours.
Use data from the graph to calculate the difference in the mean number of hours
spent by each species looking around in the area where there were many
predators.
Show your working.
Difference ____________________ hours
(2)
(b) The scientists concluded that these herbivores spend more time looking for
predators in areas where there are many predators.
Do these data support this conclusion? Give reasons for your answer.
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___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
Page 1 of 46
, ___________________________________________________________________
(4)
(c) The behaviour of the herbivores in having their heads up has a benefit but it also
has costs. The benefit is being able to see, and escape from, predators.
Suggest and explain one cost to the herbivores of this behaviour.
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___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
(2)
(Total 8 marks)
Q3.
Algae are photosynthesising organisms. Some grow on rocky shores. Scientists
investigated the abundance of different species of algae at two sites, A and B, on a rocky
shore. Site A was on the upper shore and site B was on the lower shore. The diagram
shows the location of sites A and B on the rocky shore.
Table 1 shows some of the results the scientists obtained.
Table 1
Site A Site B
Upper shore Lower shore
Gigartina spinosa
Species of Gigartina
algae with leptorhynchos Rhodoglossum affine
percentage
Gigartina canaliculata Laurencia pacifica
cover more
than 1% Gelidium coulteri Gastroclonium coulteri
Rhodoglossum affine Centroceros
clavulatum
Gigartina canaliculata
Corallina
vancouveriensis
Page 1 of 46
, (a) The scientists recorded data from 40 large rocks at each site.
Describe one method that the scientists could have used to ensure that the large
rocks were chosen without bias.
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
(2)
(b) The scientists used percentage cover rather than frequency to record the
abundance of algae present
Suggest why.
___________________________________________________________________
___________________________________________________________________
(1)
(c) Apart from availability of water, describe and explain how two abiotic factors may
have caused differences in the species of algae growing at sites A and B.
Factor 1 ____________________________________________________________
Explanation _________________________________________________________
___________________________________________________________________
Factor 2 ____________________________________________________________
Explanation _________________________________________________________
___________________________________________________________________
(2)
(d) Use the information provided in Table 1 to explain why the diversity of consumers
will be greater at site B.
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
(2)
(e) The scientists also investigated the algae eaten by two consumers found on the
rocky shore, the sea slug and the shore crab. The scientists carried out their
investigation in a laboratory.
• They put each consumer into a separate tank through which aerated seawater
flowed slowly.
Page 1 of 46
Marks = 167 Time Allowed 222 minutes
Q1.
(a) What is a gene pool?
___________________________________________________________________
___________________________________________________________________
(1)
(b) Lord Howe Island in the Tasman Sea possesses two species of palm tree which
have arisen via sympatric speciation. The two species diverged from each other
after the island was formed 6.5 million years ago. The flowering times of the two
species are different.
Using this information, suggest how these two species of palm tree arose by
sympatric speciation.
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
(5)
(Total 6 marks)
Q2.
Impala and wildebeest are species of herbivore that live in large groups. They spend most
of their time feeding with their heads near the ground.
Scientists investigated the relationship between the number of predators in an area and
the mean proportion of time these herbivores spent with their heads up, looking around
rather than feeding. They obtained data from groups of impala and wildebeest in two
areas. In one area there were few predators and in the other area there were many
predators.
Page 1 of 46
,The graph shows their results. The bars show standard deviations.
(a) The scientists observed both groups of animals for 75 hours.
Use data from the graph to calculate the difference in the mean number of hours
spent by each species looking around in the area where there were many
predators.
Show your working.
Difference ____________________ hours
(2)
(b) The scientists concluded that these herbivores spend more time looking for
predators in areas where there are many predators.
Do these data support this conclusion? Give reasons for your answer.
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
Page 1 of 46
, ___________________________________________________________________
(4)
(c) The behaviour of the herbivores in having their heads up has a benefit but it also
has costs. The benefit is being able to see, and escape from, predators.
Suggest and explain one cost to the herbivores of this behaviour.
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
(2)
(Total 8 marks)
Q3.
Algae are photosynthesising organisms. Some grow on rocky shores. Scientists
investigated the abundance of different species of algae at two sites, A and B, on a rocky
shore. Site A was on the upper shore and site B was on the lower shore. The diagram
shows the location of sites A and B on the rocky shore.
Table 1 shows some of the results the scientists obtained.
Table 1
Site A Site B
Upper shore Lower shore
Gigartina spinosa
Species of Gigartina
algae with leptorhynchos Rhodoglossum affine
percentage
Gigartina canaliculata Laurencia pacifica
cover more
than 1% Gelidium coulteri Gastroclonium coulteri
Rhodoglossum affine Centroceros
clavulatum
Gigartina canaliculata
Corallina
vancouveriensis
Page 1 of 46
, (a) The scientists recorded data from 40 large rocks at each site.
Describe one method that the scientists could have used to ensure that the large
rocks were chosen without bias.
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
(2)
(b) The scientists used percentage cover rather than frequency to record the
abundance of algae present
Suggest why.
___________________________________________________________________
___________________________________________________________________
(1)
(c) Apart from availability of water, describe and explain how two abiotic factors may
have caused differences in the species of algae growing at sites A and B.
Factor 1 ____________________________________________________________
Explanation _________________________________________________________
___________________________________________________________________
Factor 2 ____________________________________________________________
Explanation _________________________________________________________
___________________________________________________________________
(2)
(d) Use the information provided in Table 1 to explain why the diversity of consumers
will be greater at site B.
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
(2)
(e) The scientists also investigated the algae eaten by two consumers found on the
rocky shore, the sea slug and the shore crab. The scientists carried out their
investigation in a laboratory.
• They put each consumer into a separate tank through which aerated seawater
flowed slowly.
Page 1 of 46
