NCEA Level 2 Biology (90461) 2009 — page 1 of 4
Assessment Schedule – 2009
Biology: Describe concepts and processes relating to ecology (90461)
Evidence Statement
Q
ONE
(a)
Achievement
Achievement with Merit
Describes mutualism OR
exploitation:
Eg, mutualism is a relationship
between members of two species,
where each gain benefit. (May
state that both have increased
survivorship.)
OR
Eg, exploitation is a relationship
between members of two species,
where one benefits at the expense
of the other. (May describe specific
examples such as parasitism or
predation).
(b)
Describes intra-specific
competition AND inter-specific
competition.
Eg, intra-specific competition (for
resources when limited) occurs
between members of the same
species.
Inter-specific competition occurs
between members of different
species.
Explains an aspect of competition
appropriate to the diagram.
Eg, inter-specific competition between
native bird species and exotic bird
species will increase in Zone B with
the arrival / increase of exotic species.
Eg, trees growing in all zones compete
with members of both their own
species and members of other tree
species for light / minerals / water /
space.
Achievement with Excellence
NCEA Level 2 Biology (90461) 2009 — page 2 of 4
(c)
Describes: Adaptation is the
process whereby an organism
becomes better suited to its habitat,
or in some way increases its
chances of survival.
Gives two appropriate examples of
different types of adaptations.
Eg, structural adaptations are
physical structures, like the wings
of a bird that enable flight.
Eg, adaptations help animals
survive. Fish swimming in shoals
is a behavioural adaptation.
Explains how adaptations help
animals avoid the threats or exploit
available resources in their habitats.
Discusses why adaptations help
animals increase their chances of
survival or reproductive success.
Gives one appropriate example at
merit level and one at describe level.
Gives one example at excellence level.
Eg, the streamlined body shape of a
shark is a structural adaptation that
enables it to be an efficient swimmer
to catch prey.
Eg, shoaling fish swim as a
coordinated group, this is a
behavioural adaptation that confuses
predators.
Eg, the kea has a structural adaptation
of dense plumage to provide insulation
in a cool alpine environment.
Eg, Harrier hawks hunt for rats and
mice during the day, this behavioural
adaptation reduces inter-specific
completion with moreporks / owls that
hunt during the night.
Eg, streamlining of a shark allows it to
be an efficient swimmer and its
counter shading allows it to be better
hidden in the water column, therefore
more able to remain unseen by its
prey.
Eg, shoaling fish that swim as a
coordinated group in the same
direction can confuse their predators
and decrease the chances of individual
capture.
Eg, making venom is a physiological
adaptation that enables animals such as
snakes to paralyse prey, therefore
increasing predation success.
Eg, the mating rituals of a number of
animals are behavioural adaptations
that ensure that good mate selection
takes place resulting in the genes of
those organisms with the best displays
/ calls / dances to be passed on.
ONE
2a = A
1a + 1m = M
1a + 1e = E
TWO
Describes succession as a pattern
by which communities in a new
habitat change over time
AND one of zonation OR
stratification.
Explains the pattern of succession
where pioneer species colonise and
modify a sterile environment / bare
ground through to a climax
community.
AND
patterns of zonation OR stratification
are explained for an appropriate
environmental gradient.
Discusses how the ecological pattern
of succession is different from the
patterns of zonation AND
stratification.
Gives appropriate examples.
Eg, zonation is a horizontal
banding pattern on a rocky shore.
Eg, stratification is a vertical
layering of plants in a native
forest.
The abiotic factor causing the
environmental gradient is named.
Two parts of the environment are
compared to show an understanding of
how a change in an abiotic factor can
produce a distribution of species.
Examples given of named species in
zones or strata OR some strata are
identified.
Eg, The change in the species
composition over a period of time is
called succession. The first organisms
to colonise a new habitat, that may
become available through a landslip,
are pioneer plant species that are
tolerant of low soil fertility. When
pioneer species die and decompose
they increase soil fertility. Other
species grow and shade them out.
Replacement continues until a stable
climax community is established.
NCEA Level 2 Biology (90461) 2009 — page 3 of 4
THREE
(a)
Describes any two of the following
three terms: producer, primary
consumer or secondary consumer
with correct examples identified
from the diagram.
Eg, a producer makes their own
food by photosynthesis / using
light energy.
Eg, sea grass / phytoplankton /
mangroves / rushes.
Eg, a primary consumer is a
herbivore and eats plants.
Eg, zooplankton
Eg, a secondary consumer is a
carnivore (or omnivore) and eats
herbivores.
Eg, shellfish / mud snails / crabs /
marine worms / young fish.
(b)
Describes that the biomass /
number of individuals / energy of
each trophic level is less than that
of the level below.
Explains the concept that only a small
proportion of energy is available to the
next step in the food chain. The rest of
the energy is lost via respiration / as
heat (90%) leaving only 10% as
biomass that can directly transfer
energy.
There is not enough energy left in the
food chain, after four or five steps, to
support a longer food chain.
(c)
Describes the importance of
decomposers and what would
happen if decomposers were
unavailable or inactive.
Explains the importance of
decomposers in the recycling of
nutrients.
Eg, decomposers are consumers
that feed on / breakdown dead
organisms or their waste products
and if there were none, nutrients
would remain locked in the dead
plant and animal cells / recycling
of nutrients would be stopped.
Three
2a = A
Eg, in consuming dead or decaying
organisms, decomposers release
nutrients from dead organisms into the
soil to improve soil fertility / to be
used by plants / nitrogen is returned
to the soil and absorbed by the roots of
plants.
1a+1m= M
Discusses the importance of
decomposers in an ecosystem.
Eg, decomposers return chemical
elements to an ecosystem in a form
that can be used by plants, which in
turn feed animals. Nitrates are
returned to the soil and are absorbed
by the roots of plants. Nitrates (which
are combined with carbon compounds)
make plant proteins. Nitrate ions are
useless to animals which must obtain
their nitrogen in the form of protein by
eating plants or other animals.
Nitrogen / carbon passes from one
organism to another along the food
chain. If decomposers were to
disappear, the chemical cycles that
sustain life would come to a halt.
1a + 1e= E
NCEA Level 2 Biology (90461) 2009 — page 4 of 4
Judgement Statement
Achievement
Achievement with Merit
Achievement with Excellence
Note: Lower case a, m, e may be used throughout the paper to indicate contributing evidence for overall grades for
questions. Only the upper case A, M and E grades shown at the end of each full question are used to make the final
judgement.
2A
2M
1E+1M