Questions
Q1.
(i) Complete the sentence by putting a cross (
Fleas are parasites that feed on foxes.
Another example of parasites are
) in the box next to your answer.
(1)
A cleaner fish
B lichens
C mistletoe
D oxpeckers
(ii) Peas and beans are known as legumes.
They form a mutualistic relationship with the bacteria in their roots.
Explain the importance of this mutualistic relationship to the legumes.
(3)
..............................................................................................................................................
..............................................................................................................................................
..............................................................................................................................................
..............................................................................................................................................
..............................................................................................................................................
..............................................................................................................................................
Q2.
The diagram shows the life cycle of the human tapeworm.
(i) The tapeworm absorbs food in the human intestine.
Complete the sentence by putting a cross (
A tapeworm is an example of a
) in the box next to your answer.
(1)
A living indicator
B mutualist
C parasite
D producer
(ii) Use information in the diagram to describe how an adaptation of the tapeworm enables it to live in the
human intestine.
(2)
..............................................................................................................................................
..............................................................................................................................................
..............................................................................................................................................
..............................................................................................................................................
(iii) Using information in the diagram, suggest how humans could avoid becoming infected with
tapeworms.
(2)
..............................................................................................................................................
..............................................................................................................................................
..............................................................................................................................................
..............................................................................................................................................
Q3.
The photograph shows another type of worm.
These are tube worms that live near hydrothermal vents.
Explain the relationship between these tube worms and chemosynthetic bacteria.
(3)
..............................................................................................................................................
..............................................................................................................................................
..............................................................................................................................................
..............................................................................................................................................
..............................................................................................................................................
..............................................................................................................................................
Mark Scheme
Q1.
Question
Number
(i)
Question
Number
(ii)
Answer
C
Answer
An explanation
linking the following
points: • bacteria
provides nitrates for
the plants (1) • (by)
nitrogen-fixation /
converting nitrogen
into nitrates (1)
• (nitrates) provide
protein / for growth
(1)
Acceptable answers
Mark
Acceptable answers
(1)
Mark
Accept nitrogenfixing bacteria
(3)
Q2.
Answer
(i)
(ii)
(iii)
C
Acceptable
answers
parasite
Mark
(1)
A suggestion linking
two of the
following:
•
suckers on the
head /adaptation of
the head (1)
•
attaches to the
intestine (1) OR
•
a very long thin
shape / large surface
area (1)
•
for absorption
(1) OR
•
surface / skin (1)
•
resistant to
enzymes (1)
A suggestion
including two of the
following:
•
cooking meat
thoroughly (1)
•
do not eat meat
/become a
vegetarian /
vegan(1)
•
destroy/don't eat
the cysts in the
meat(1)
•
prevent animals
from eating
tapeworm eggs (1)
•
worm the animal
(1)
Accept hooks, teeth
for suckers Reject
large intestine
Accept long flexible
shape Ignore
references to
resistance to
stomach acid Ignore
references to larvae,
eggs and
reproduction
Answer
Acceptable
answers
(2)
Accept food/pork
for meat
(2)
Q3.
An explanation
including three of
the following:
•
(chemosynthetic)
bacteria live in (the
gut of) the tube
worms (1)
•
the bacteria
convert sulphurous /
hydrogen sulphide
compounds (1)
Mark
Accept
sulphurAccept
bacteria make food
for worms Accept
protection Accept
mutualism / mutual
benefit / mutual
relationship
(3)
•
into food for the
tube worms (1)
•
the tube worms
provide place for the
bacteria to live /
provides oxygen for
bacteria (1)
•
this is a
mutualistic
relationship (1)