Download File - Year 11 Science

Biology Mixed Questions
Q1.
(a) Complete the sentence by putting a cross (
Food is moved through the digestive system by
) in the box next to your answer.
(1)
A diffusion
B digestion
C peristalsis
D active transport
(b) State two roles of bile in digestion.
(2)
*(c) Describe the roles of the enzymes involved in digestion.
(6)
(d) Explain how the structure of the villi allows efficient absorption in the small intestine.
(3)
(Total for Question is 12 marks)
Q2.
The photograph shows a sperm cell and an egg cell just before fertilisation.
Describe the structure of DNA.
(3)
Q3.
(a) Describe how a section of DNA determines the structure of a protein.
(4)
*(b) Describe the structure of DNA, including the roles of the scientists involved in its discovery.
(6)
Human DNA was sequenced during the Human Genome Project.
(c) Explain how the Human Genome Project has contributed to advances in medicine.
(2)
(Total for Question is 12 marks)
Q4.
The family pedigree shows the inheritance of sickle cell disease through three generations.
(i) Calculate the percentage of the offspring from the first generation who are heterozygous for sickle
cell disease.
(1)
(ii) Explain why the offspring produced by the first generation parents are not the same as those
predicted in a Punnett square.
(2)
(iii) Person W and his partner have a third child.
State the probability that this child will have sickle cell disease.
Complete the Punnett square to show this.
(2)
(iv) Complete the sentence by putting a cross (
The genotype of person V is
) in the box next to your answer.
(1)
A
B
C
D
homozygous dominant
homozygous recessive
heterozygous
carrier
Q5.
(a) Purple tomatoes are transgenic plants that have been produced by genetic engineering.
(i) As a result of genetic modification, these tomatoes produce a new substance which has health
benefits and turns
the tomatoes purple.
Name this substance.
(1)
(ii) What is inserted into the DNA of another plant to make it transgenic?
Put a cross ( ) in the box next to your answer.
(1)
A a gene from another species
B a gene from the same species
C chromosomes from the same species
D proteins from another species
*(b) Describe how Agrobacterium tumefaciens can be used to create transgenic plants.
(6)
(c) Bacillus thuringiensis contains a gene that codes for a toxin.
Explain one advantage and one disadvantage of introducing this gene into crop plants.
(4)
(Total for Question = 12 marks)
Q6.
Height can be used to monitor growth.
(a) The graph shows a percentile chart for height for males aged between 2 and 20 years.
(i) Describe how the height of males changes from the age of 2 to 20 years.
(2)
(ii) Calculate the difference in height of an 11 year old male in the 95th percentile and an 11 year old
male in the 5th percentile.
(2)
(iii) Explain what is meant by the 95th percentile on this graph.
(2)
(b) Protein is needed for growth.
(i) Name the first stage of protein synthesis.
(1)
(ii) Complete the sentence by putting a cross ( ) in the box next to your answer.
The second stage of protein synthesis produces a
(1)
A
B
C
D
polypeptide made of amino acids
polypeptide made of bases
strand of mRNA made of amino acids
strand of mRNA made of bases
(Total for Question is 8 marks)
Q7.
Describe how fossil evidence can be used to show that humans have evolved.
(2)
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Q8.
Huntington's disease is a genetic disorder.
The genetic diagram shows the inheritance of this disorder.
(a) (i) Use words or letters from the box to complete the following sentences.
(2)
Huntington's disease is caused by a ........................................................... allele.
People with Huntington's disease can have the genotype Hh or ........................................................... .
(ii) Complete the Punnett square to show the potential offspring of two parents heterozygous for
Huntington's disease.
(2)
(iii) State the probability that a child of two parents, heterozygous for Huntington's disease, will have
the disease.
(1)
.............................................................................................................................................
(b) The genetic diagram shows the inheritance of cystic fibrosis.
(i) Explain why, if both sets of parents are heterozygous, the chance of inheriting Huntington's disease
is greater than the chance of inheriting cystic fibrosis.
(2)
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(ii) Complete the sentence by putting a cross ( ) in the box next to your answer.
A symptom of cystic fibrosis is the overproduction of
(1)
A
B
C
D
mucus
red blood cells
stomach acid
white blood cells
(iii) Explain why a man with cystic fibrosis may be infertile.
(2)
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Mark Scheme
Q1.
Answer
(a)
(b)
C peristalsis
 neutralisation (of
stomach acid) / raise
pH (1)
 emulsification /
break down of fats
(1)
QWC
Acceptable
answers
*(c)
Mark
(1)
Accept makes
stomach / intestine
contents more
alkaline Accept
breaks down large
droplets /globules /
increases surface
area of fats Reject
molecules broken
down
Indicative Content
A description
including some of
the following points
in a logical sequence
Names of enzymes:
 carbohydrases
 named
carbohydrase eg
amylase
 proteases
 named protease
eg pepsin
 lipases
 named
lipaseGeneral points
about enzyme
action:
 breakdown of
large / insoluble /
named molecules
into small / soluble /
named molecules
 for absorption
 catalysts
 speeds up
reactions
 active sites that
bind to substrate
 idea of
specificitySpecific
points:
 carbohydrates/
(2)
Mark
(6)
Level
1
0
1-2
starch are broken
down
 into sugars /
glucose
 proteins /named
protein are broken
down
 into amino acids
 fats / oils / lipids /
named lipid are
broken down
 into fatty acids
/glycerol
No rewardable content
 a limited description of enzyme action
that includes at least three points
 the answer communicates ideas using
simple language and uses limited scientific
terminology
 spelling, punctuation and grammar are
used with limited accuracy
2
3-4
 a simple description of enzyme action
that includes at least six points
 the answer communicates ideas
showing some evidence of clarity and
organisation and uses scientific terminology
appropriately
 spelling, punctuation and grammar are
used with some accuracy
3
5-6
 a detailed description of at least nine
points
 the answer communicates ideas clearly
and coherently uses a range of scientific
terminology accurately
 spelling, punctuation and grammar are
used with few errors
Answer
(d)
An explanation
linking three of the
following points
 (E) more /fast /
maximises diffusion /
absorption (1)
 (S) microvilli (1)
 (E) large surface
area (1)
 (S) single layer
of cells / one cell
thick / thin walls (1)
 (E) small
diffusion distance (1)
Acceptable
answers
To award all three
marks at least one
structure (S) and
explanation (E) must
be linked together.
Award once, linked
to any structure
Ignore efficient (in
stem) / easier
Reject ref to cell wall
Mark
(3)
 (S) capillary
network / good blood
supply / capillaries
inside villus (1)
 (E) maintains
diffusion gradient (1)
Q2.
Q3.
Answer
(a)
A description
including the
following linked
points
 ref to a gene
(coding for
protein)(1)
 sequence of
bases determines
sequence of amino
acids (1)
 idea of one code
/ triplet / codon / 3
bases (for one amino
acid) (1)
 several amino
acids make up a
protein /
(poly)peptide (1)
 transcription /
Acceptable
answers
Mark
Accept on either
DNA or RNA base
pairs
Accept a chain of
amino acids
eg mRNA made
eg mRNA attached
to ribosome
(4)
detail of transcription
(1)
 translation /
detail of translation
(1)
Indicative Content
QWC
Level
1
*(b)
0
1-2
Mark
A description
including some of
the following points
in a logical sequence
Points relating to
DNA structural
features:
 two strands
 double helix
 (contains) bases
 A, T, C, G
 adenine / A
paired with thymine /
T
 guanine / G
paired with cytosine /
C
 hydrogen / H
bonds joining
basesContributions
from Scientists:
 X-ray
(crystallography)
being used
 to show helical
structure
 to show diameter
of molecule
 how base pairs
are arranged was
shown
 how strands are
arranged was shown
 modelling
 reference to
using other people's
(6)
ideas
No rewardable content
 a limited description that includes either:
at least three DNA features OR one
contribution
 the answer communicates ideas using
simple language and uses limited scientific
terminology
 spelling, punctuation and grammar are
used with limited accuracy
2
3-4
 a simple description that includes at
least three features of DNA and at least one
contribution OR two features of DNA and
two contributions.
 the answer communicates ideas
showing some evidence of clarity and
organisation and uses scientific terminology
appropriately
 spelling, punctuation and grammar are
used with some accuracy
3
5-6
 a detailed description of the structure of
DNA that includes at least three features
and two contributions.
 the answer communicates ideas clearly
and coherently uses a range of scientific
terminology accurately
 spelling, punctuation and grammar are
used with few errors
Answer
(c)
An explanation to
include two of the
following points
linked together
 genes / base
sequence (on human
chromosome)
identified (1)
 identification of
faulty / mutated
genes (1)
 people can be
tested for a genetic
disorder (1)
 ref to
development of gene
therapy (1)
 idea that
appropriate /early
/personalised /
genomic medication /
counselling can be
given (1)
Acceptable
answers
Accept base pair
sequence gene map
Accept idea that
genes can be linked
to disease Accept
diagnosis of cancer
Accept a description
of gene therapy
Mark
(2)
Q4.
Answer
(i)
(ii)
75%
An explanation
linking two of the
following:
 Punnett square
would predict 50%
Acceptable
answers
Mark
(1)
accept ratios or
probabilities instead
of percentages
actual offspring are
75% accept
(2)
normal 50% carrier
(1)
 actual offspring
are not 50% carrier
(1)
 the probability is
applied to each child
not the overall
offspring (1)
(iii)
(iv)
Probability = 50%
Ratio 2/4, 2:2, can
be given for
probability 1 mark
for correct gametes
1 mark for completed
Punnett square with
correct probability
A
homozygous
dominant (BB)
references to
random assortment
Accept reverse order
for gametes Accept
letters other than B/b
(but alleles must be
the same letter)
50% mark can only
be given if 50% of
the offspring are
homozygous
recessive
(2)
(1)
Q5.
Answer
(a) (i)
(a) (ii)
QWC
flavonoids /
bioflavonoids
A a gene from
another species
*(b)
Acceptable
answers
anthocyanins
antioxidants
Mark
(1)
(1)
Indicative Content
Mark
A description
including some of
the following points
genetic
modification
 transferring a
gene from one
organism to another
 restriction
enzymes to cut the
gene out
 plasmids used to
carry gene
 sticky ends to
join complementary
bases
 ligase to join the
DNAuse of
Agrobacterium
 Agrobacterium is
a vector (for the
gene)
 the
(6)
Agrobacterium has a
suitable gene added
to it
 example of a
suitable gene eg
drought resistance /
insect resistance /
larger yield / for
flavonoids
 Agrobacterium
naturally invades
plant cells
 its DNA is
incorporated into the
plant's
DNAproduction of
plants
 plant sprayed
with Agrobacterium
 crown gall
(formed)
 crown gall is cut
into small pieces
 leaf discs are
incubated with
Agrobacterium
Level
1
0
1-2
 (crown gall tissue
/ leaf discs) grown in
tissue culture
 explants
 grown into crops
No rewardable content
 a limited description of at least one of
the areas involved in creating transgenic
plants. Steps may be missing or out of
sequence.
 the answer communicates ideas using
simple language and uses limited scientific
terminology
 spelling, punctuation and grammar are
used with limited accuracy
2
3-4
 a simple description of at least two of
the areas involved in creating transgenic
plants or a detailed description of one area
involved in creating transgenic plants
 the answer communicates ideas
showing some evidence of clarity and
organisation and uses scientific terminology
appropriately
 spelling, punctuation and grammar are
used with some accuracy
3
5-6
 a detailed description of the genetic
modification, use and production of
transgenic plants. Steps should be in
sequence.
 the answer communicates ideas clearly
and coherently uses a range of scientific
terminology accurately
 spelling, punctuation and grammar are
used with few errors
Answer
(c)
An explanation of
one advantage for
two marks
 crop produces a
toxin that kills insects
(that eat plant)(1)
 so less damage
by insect / increased
crop yield (1)
 less man-made
chemicals used /
specific to pests /
less pollution (1)An
explanation of one
disadvantage for two
marks
 cross pollination /
fertilisation with other
plants (species) (1)
 producing weeds
that contain the
toxin(1)
 non target
organisms may be
affected (1)OR
 idea of large
areas of
monocultures (1)
 reduction in
insect numbers /
biodiversity (1)
 negative impact
on food chains
(1)OR
 GM crops cost
more (1)
 Farmers cannot
afford them / become
reliant on them (1)
Acceptable
answers
accept references
to ICP accept does
not kill other insects
Mark
(4)
Q6.
Answer
(a)(i)
Acceptable
answers
Accept increases
Mark
(2)
 height / growth
increases until 15/18
(years old) (1)
 height / growth
starts to level off /
plateau / slows down
after 15/18 (1)
(a)(ii)
 155 / 155.5 –
132 / 132.5 (cm) (1)
 answer between
22 and 23.5 (cm) (1)
(a)(iii)
Q7.
Q8.
(b)(i)
An explanation
linking two points
 95% will be
smaller / that height
or smaller
OR
5% will be taller / at
that height or taller
(1)
 at that age (1)
transcription (1)
(b)(ii)
A
and then levels off /
height increases
(until 20) for 1 mark
ecf on figures
quoted Accept
growth stops after 18
Two marks for
correct bald answer
ecf
2 marks cannot be
awarded if mp 1 not
correct
(2)
(2)
Accept phonetic
spelling
(1)
(1)