Download Describe aspects of biology (90188)

NCEA Level 1 Science (90188) 2009 — page 1 of 4
Assessment Schedule – 2009
Science: Describe aspects of biology (90188)
Evidence Statement
Q
ONE
(a)
Achievement
Achievement with Merit
Correct statement about
why a person suffering a
viral infection will not
suffer effects from toxins
(a)
Correct explanation why viruses
do not produce toxins AND how
toxins are produced.
(m)
Examples:
Viruses do not produce toxins as
they do not carry out life processes /
respiration / excretion / other named
life process (ie why not living).
Examples:
Viruses do not respire /
excrete / carry out life
processes / are not living.
OR
Viruses require living cells
to reproduce / replicate.
Correct statement about
how toxins are produced.
(a)
Examples:
Toxins produced as a
result of (cellular)
metabolism / respiration /
excretion / digestion.
Achievement with Excellence
AND
Toxins are a waste product
produced when Bacteria / living
things digest food / respire /
excrete.
(DO NOT accept idea that enzymes
are toxins.)
Toxins are excreted waste.
(Not just waste products –
must refer to life process.)
(b)
Correct statements. (a)
Eg:
Toxins build up as bacteria
reproduce / excrete over
time. (a)
Bacteria reproduce using
binary fission / as cell
divides in two. (a)
Very few bacteria at start /
bacteria build up over time
(a)
Bacteria replicate (fast) in
right / warm / moist /
nutrient rich conditions
(a).
Suff.
2 × a =A
Correct explanation why bacteria
increase AND why toxins increase
over time. (m)
In an initial infection there are very
few bacteria. Bacteria reproduce
rapidly over 24 hr using binary
fission / cell divides in two as
quickly as every 20 min, therefore
in 24 hr the numbers are very high.
AND
Toxin amount is dependent on the
number of bacteria respiring /
excreting, therefore when the
numbers are higher after 24 hrs the
amount of toxin will be very high.
(Must be clear candidates know
what a toxin is.)
1×m=M
Discusses fully why a person would feel
unwell after 24 hours by relating
symptoms to bacterial life processes. (e)
(Must link binary fission AND respiration OR
excretion to toxin build up due to large
numbers)
Eg:
Bacteria reproduce by binary fission, which
happens rapidly, under optimal conditions (of
warmth, moisture, food) leading to high
numbers in a short time. Therefore when
there are large numbers of bacteria carrying
out respiration / excretion after 24 hrs, large
amounts of toxin are produced / excreted
leading to a person feeling unwell.
1×e=E
NCEA Level 1 Science (90188) 2009 — page 2 of 4
TWO
(a)
Identifies THREE parts.
(a)
Eg:
A = spores
B = sporangium / spore
capsule / case
C = (reproductive) hyphae
/ sporangiophore
D = (feeding) hyphae /
mycelium
TWO correct roles
identified. (a)
Eg:
A - used for reproduction /
making new fungi.
B -holds / disperses spores
C- holds up sporangium
D- used for digestion /
feeding / how food gets
into fungus.
(b)
Definition of
Fermentation. (a)
Eg:
Anaerobic respiration /
release of energy from
sugar that takes place
without / in the absence of
oxygen / respiration
without oxygen.
OR
word / formulae equation
acceptable:
OR
sugar (glucose) → carbon
dioxide + alcohol
(ethanol)
(allow yeast and energy to
be in equation for A only)
ONE correct statement
for role of sugar (a)
Eg:
Sugar is needed for
respiration / life processes
/ food source (NOT
fermentation)
ONE correct yeast life
process described (a)
Respiration, excretion,
reproduction, nutrition,
growth.
Suff.
2×a=A
Explains the role of THREE
parts.
Parts must be named correctly.
(m)
Eg:
For A: Spores are small / light
reproductive parts of the fungus,
that disperse .
For B: Sporangia are spore sacs /
holders for spores which disperse
the spores or mature the spores.
For C: Reproductive hyphae hold
sporangium up so enable better
dispersal of spores.
For D: (Feeding) hyphae absorb
nutrients / produce digestive
enzymes / carry out extra cellular
digestion.
(Do not accept roots / seeds etc as
names for parts but analogy okay.)
Describes fermentation and
explains why sugar is needed OR
why yeast is used in bread
making. (m)
CORRECT word equation needed.
Eg:
sugar (glucose) → carbon dioxide +
alcohol (ethanol) (allow energy)
AND
Anaerobic respiration /
fermentation is the release of energy
from sugar that takes place in the
absence of oxygen. (must be clear
that respiration is anaerobic /
without oxygen).
AND
Why sugar is needed: energy
molecule broken down in
(anaerobic) respiration / provides
food / energy supply for yeast to
maximize growth / reproduction to
increase rate of respiration / faster
energy source than flour.
Discusses the role of THREE correctly
named parts. (e)
Eg:
For A: Spores are the reproductive units for
fungi, they carry the genetic code / DNA to
produce another identical fungus OR they are
small / light to be carried a distance by wind
to land and germinate / start growing on a
food source (ie need to link form to function).
For B: Sporangia are sacs which carry /
produce the spores. When the spores are ripe /
mature they burst releasing the spores into the
air.
For C: The reproductive hyphae are designed
to hold up the sporangia to enable the spores
to be spread (in the air).
For D: The feeding hyphae carry out extra
cellular digestion, secreting enzymes to break
down food molecules outside of the fungal
organism. The nutrients are then absorbed.
Describes fermentation and explains why
sugar is needed AND the life processes of
yeast in bread making. (e)
CORRECT word equation needed
sugar (glucose) → carbon dioxide + alcohol
(ethanol) (may include energy)
AND
Yeast needs sugar as its food / energy supply
for respiration / fermentation to release
energy needed for growth / reproduction /
binary fission.
AND
Yeast ferments sugar / carries out anaerobic
respiration using sugar and produces alcohol
and CO2 gas, which causes the bread to rise.
Eg:
sugar (glucose) → carbon dioxide + alcohol
Yeast is fermenting, ie anaerobically respiring
without using oxygen, using the sugar as
easily released energy to grow and reproduce.
It excretes CO2 gas as waste which makes
bread rise quickly under right conditions of
warmth, food, moisture.
OR
The function of the yeast: Yeast
carries out fermentation /
(anaerobic) respiration producing
CO2 which causes the bread to rise.
1×m=M
1×e=E
NCEA Level 1 Science (90188) 2009 — page 3 of 4
THREE
(a)
Correct genotype. (a)
Accept either ee or
homozygous recessive.
Correct use of recessive
AND allele. (a)
Eg:
Recessive is an allele
which will only be
displayed when there is
more than one present / no
dominant allele present.
Correct definition for
recessive OR allele (a)
Eg:
Recessive traits are
masked by dominant traits.
An allele is an alternative
form of a gene.
(b)
Correct statement. (a)
Extra digits (E) is
dominant over normal
digits (e) so (e) may be
present in cats, but stay
hidden in Ee.
Correct genotype
combinations (a).
Normal digits (ee) could
show up in a Ee × Ee cross
or a Ee x ee cross.
OR
Correct Punnett square
for either / both of above
E
e
E
EE
Ee
e
Ee
ee
e
e
E
Ee
Ee
e
ee
ee
Explains the genotype of a normal
cat using required terms, allele
and recessive. (m)
Eg:
The cat has two alleles for normal
digits. This allele is recessive which
means that, in order for it to be
displayed, two of the normal alleles
are needed. It will be hidden /
masked if a dominant allele is
present, therefore the genotype is ee
(homozygous recessive) as the cat
has normal digits.
(Must use terms allele and recessive
correctly and clearly show that
dominant allele will mask / hide
and give polydactyl phenotype.)
Correct explanation for choice of
parent genotypes. (m)
Must use terms allele, gene and
recessive correctly.
Normal digits (ee) could show up in
an Ee × Ee cross (or Ee × ee). It
would be impossible if the parents
were Ee and EE.
OR
At least one parent ie heterozygous /
Ee / carries dominant and recessive
allele for gene. For kitten to not
have extra digit it must inherit the
recessive allele from both parents.
OR
25% or 50% chance will only be
displayed in a large sample, not
necessarily a single litter.
Idea of lower percentage being less
likely is clearly explained
Correct interpretation of
punnet phenotypes (a)
Eg 25% chance of normal
kitten, 75% polydactyl
Discusses how a normal digit kitten can be
produced AND links the outcome to the
statistical probability of it happening.
MUST include Punnett square and use
gene / allele correctly. (e)
At least one of the parents is heterozygous /
Ee / carry dominant and recessive allele for
gene. For kitten to not have extra digit it must
inherit the recessive allele from both parents.
AND
Statistically every time an Ee × Ee cross is
carried out there is 25% chance that offspring
would be normal (ee) or 50% for ee x Ee The
normal trait may not be expressed at all.
PLUS
Correct Punnett square.
OR
Explains both possible parent
combinations and outcomes with punnett
squares. (e)
Eg:
At least one of the parents is heterozygous,
but the other parent may be homozygous
recessive or heterozygous.
If the other parent is homozygous recessive,
statistically there is a 50% chance that the
offspring will inherit both recessive alleles,
which will be expressed as normal digits.
If the other parent is heterozygous, there is a
25% chance that the offspring will inherit
both recessive alleles.
e
e
Suff.
2×a=A
1×m=M
E
Ee
Ee
e
ee
ee
E
e
1×e=E
E
EE
Ee
e
Ee
ee
NCEA Level 1 Science (90188) 2009 — page 4 of 4
FOUR
Two correct statements.
(2 × a)
Eg:
Variation in meiosis can
be caused by crossing over
/ shuffling / independent
assortment.
Variation in meiosis can
lead to increased survival
chances.
Mitosis would cause a
doubling of chromosome
number if used in
reproduction.
Meiosis halves the number
of chromosomes.
Cells produced from
meiosis lead to the correct
number of chromosomes
at fertilisation.
Diagram or description in
words showing the process
of mitosis / meiosis.
Two correct statements, one
explained. (m)
Explains fully why meiosis is used for
reproduction AND mitosis is not. (e)
Eg:
Variation in meiosis occurs as a
result of crossing over, or
“shuffling” meaning that each of the
4 daughter cells produced differs
from the rest leading to increased
chances of survival.
Eg:
Cells produced in mitosis are all identical and
carry a full set of chromosomes which would
mean at fertilisation the chromosome number
would double. Whereas in meiosis cells with
half the number of chromosomes are
produced. Only need half the number of
chromosomes as number is restored at
fertilisation. Variation in meiosis occurs as a
result of crossing over, or “shuffling”
meaning that each of the 4 daughter cells
produced differs from the rest leading to
increased chances of survival due to mixing
up / random assortment of the alleles.
Cells produced in mitosis are all
identical and carry a full set of
chromosomes which would mean at
fertilisation the chromosome
number would double. OR the lack
of variation means the offspring are
all the same so won’t survive /
respond to change.
Meiosis is the production of
gametes / sex cells, so produces
cells with half the number of
chromosomes. Only need half the
number of chromosomes as number
is restored at fertilisation.
Correct description of
mitosis / meiosis. – eg
meiosis makes sex cells /
gametes, mitosis is for
growth AND repair,
mitosis produces daughter
cells which are identical /
can be used for asexual
reproduction.
Suff.
2×a=A
1 × (m) = M
1 × (e) = E
Judgement Statement
Achievement
Achievement with Merit
Achievement with Excellence
3A
OR
2M
1A
2M
1A
2E
Lower case a, m, e may be used throughout the paper to indicate contributing evidence for overall grades for
questions.
Only the circled upper case A, M and E grades shown at the end of each full question are used to make the final
judgement.