Read the passage.
Designer Denim Genes
USA scientists have successfully used genetic engineering to insert genes for blue pigment into cotton plants. Their aim is to get cotton plants which produce blue cotton so that denims can be manufactured without the need for dyeing. The scientists have also inserted genes that prevent cotton fibres twisting, with the aim of producing drip dry shirts made from natural fibres. Other cotton plants are being genetically engineered to produce their own insecticides. When they have perfected these new types of cotton plants, the scientists will use cloning techniques to produce large numbers of them.	
 
(i)      Name the substance in cells which carries genetic information.
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(ii)      Explain how molecules of this substance control characteristics such as blue colour in cotton plants.
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(3)
(Total 4 marks)
Q2.          The diagram shows one method of producing herbicide-resistant crop plants.

(a)     (i)      The herbicide-resistance gene is obtained from a herbicide-resistant plant.
Which structure in a cell carries the genes?
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(1)
(ii)     How is the herbicide-resistance gene cut out of this structure?
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(1)
(b)     Apart from having the herbicide-resistance gene, the herbicide-resistant plants are identical to the herbicide-susceptible plants.
Explain why.
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(2)
(c)     Suggest one advantage to a farmer of growing herbicide-resistant crops.
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(1)
(d)     Many people are opposed to the growing of herbicide-resistant crops produced in this way.
Suggest one reason why.
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(1)
(Total 6 marks)
 Q3.          Most people have a gene which produces a protein called CFTR that enables the cells lining the lungs to work efficiently. In people suffering from cystic fibrosis this gene is faulty; it produces a protein which lacks just one of the 1480 amino acids found in CFTR.
(i)      Name the molecule which carries the genetic information for producing proteins such as CFTR.
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(1)

(ii)      Explain how this molecule is responsible for the structure of proteins such as CFTR.
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(3)
(Total 4 marks)
 Q4.          The drawing shows some of the stages of reproduction in horses.

(a)     (i)      Name this type of reproduction .......................................................................
(1)
(ii)     Name the type of cell labelled A .....................................................................
(1)
(b)     Name the type of cell division taking place at the stage labelled:
(i)      B ......................................................................................................................
(ii)     C ......................................................................................................................
(2)
(c)     How does the number of chromosomes in each cell of the embryo compare with the number of chromosomes in cell A?
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(1)

(d)     When the foal grows up it will look similar to its parents but it will not be identical to either parent.
(i)      Explain why it will look similar to its parents.
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(1)
(ii)     Explain why it will not be identical to either of its parents.
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(2)
(Total 8 marks)
 Q5.          The diagram shows one method of cloning sheep.

(a)     Explain why the lambs produced by this technique are identical to each other.
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(2)
(b)     Explain why the lambs are not genetically identical to the sheep which produced the ‘foster’ eggs.
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(2)
(c)     Explain the drawback of widespread use of just a few clones of sheep.
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(3)
(Total 7 marks)

Q6.          The diagram shows how genetic engineering can be used to produce human insulin from bacteria. Ampicillin and tetracycline are two types of antibiotic. Study the diagram carefully and answer the questions.

In experiments like these, some bacteria take up the plasmid (ring of DNA) containing the insulin gene. Other bacteria fail to take up a plasmid, or they take up an unmodified plasmid (a ring of DNA which has not been cut open and which does not contain the insulin gene).
(a)     Complete the table by putting a tick () in the correct boxes to show which bacteria would be able to multiply in the presence of ampicillin and which bacteria would be able to multiply in the presence of tetracycline.
 	Bacterium can multiply in
the presence of	
 	Ampicillin	Tetracycline	
Bacterium + plasmid with the insulin gene	 	 	
Bacterium without a plasmid	 	 	
Bacterium with an unmodified plasmid	 	 	

(3)
(b)     The bacterium with the plasmid containing the insulin gene multiplies by cell division to form a clone of bacteria.
Will all the bacteria in this clone be able to produce insulin? Explain your answer.
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(3)
(Total 6 marks)
Q7.          The diagram shows how an immature egg could be used either to produce cells to treat some human diseases or to produce a baby.

          Scientists may be allowed to use this technique to produce cells to treat some human diseases, but not to produce babies.

          Using information from the diagram, suggest an explanation for this.
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(Total 4 marks)
         Spiders produce a protein thread which is extremely strong compared to man-made fibres of the same diameter.

          Explain how genes control the way the protein is made in the spider’s body.
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(Total 4 marks)
 Q9.        (a)       Animal breeders use sexual reproduction to produce new strains of animals.
How does sexual reproduction produce variation?
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(2)
(b)     A salmon is a type of fish.
Scientists have created a GM (genetically modified) ‘super’ salmon.
The scientists transferred a gene from a fish called a pout into a salmon. The gene increases the secretion of growth hormone in the salmon. The GM salmon grows much faster than an ordinary salmon, reaching market size up to one year earlier. Many more GM salmon will be grown in fish farms.
(i)      Describe how a gene can be transferred from a pout into a salmon.
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(3)
(ii)     The government might not allow the production of GM salmon.
Suggest one reason why.
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(1)
(Total 6 marks)
 Q10.          Insulin is now made by a biotechnological process. A description of the process is given below. Complete the gaps in the sentences.
(a)     The first step in the biotechnological process is that a special enzyme is used to cut
the insulin ..................................... out from a human ............................................. .
In a separate operation, a ring of bacterial ............................................... is cut open
using a special enzyme.
These two pieces of genetic material are combined together to form a new plasmid
ring which is inserted into a bacterium.
(3)

(b)     Explain why large quantities of insulin are produced when this bacterium is put into a culture medium.
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(2)

(c)     Before insulin was made in this way, it could only be obtained from sheep and pigs. Suggest two reasons, other than preventing the exploitation of animals, why it is better to obtain insulin by genetic engineering than from animals.
1 .................................................................................................................................
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2 .................................................................................................................................
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(2)
(Total 7 marks)
 Q11.          The diagram shows one way that stem cells can be produced from human embryos.

 (a)     Stem cells can be used to treat a condition such as paralysis.
Explain why.
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(b)     During pregnancy, an umbilical cord and a placenta join the embryo to the mother.
At birth the umbilical cord is cut.
Stem cells can be obtained from the umbilical cord.
Many people think that the stem cells for treating human conditions should be obtained from umbilical cords rather than human embryos.
Suggest one reason why.
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(c)     Stem cells divide by mitosis. Gametes are formed by meiosis.
Give two differences between mitosis and meiosis.
1 .....................................................................................................................
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(Total 5 marks)
 Q12.          Scientists are investigating how to reduce methane emissions from cattle.
          Most of this methane is emitted by the cows belching.
                 
          Scientists have found that less methane is belched if the cows eat high-sugar rye grass.
          This rye grass has been produced by genetic engineering.
(i)      Suggest how the high-sugar rye grass might have been produced by genetic engineering.
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(3)
(ii)      Some people might object to the growing of genetically-engineered, high-sugar rye grass for feeding cattle.
          Give two reasons why.
1 ..................................................................................................................................
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(2)
(Total 5 marks)
Q13.          (a)     Sex cells are produced by meiosis.
          Describe what happens to the chromosomes when a cell divides by meiosis.
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(2)
(b)     Darwin’s theory of natural selection depends on the fact that individual organisms within a species may show a wide range of variation.
          Explain how meiosis and sexual reproduction give rise to variation.
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(2)
(c)     Mutation may also give rise to variation.
(i)      What is meant by mutation?
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(1)
(ii)     Are all mutations harmful? Explain the reason for your answer.
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(2)
(Total 7 marks)
 Q14.         Scientists have recently cloned a mouse that had died and been frozen for 16 years.
(a)     Explain what is meant by a clone.
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(b)     The scientists used an egg cell from a living mouse and the genetic material from a brain cell of the frozen mouse.
Describe how the process of adult cell cloning could be used to clone the frozen mouse.
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(3)
(c)     People could ask scientists to use this technique to clone long-dead relatives, whose bodies have been deep-frozen.
Most people would be opposed to cloning a human from a deep-frozen, long-dead relative.
Give one reason why.
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(Total 6 marks)
 Q15.         Scientists have recently cloned a mouse that had died and been frozen for 16 years.
(a)     Explain what is meant by a clone.
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(b)     The scientists used an egg cell from a living mouse and the genetic material from a brain cell of the frozen mouse.
Describe how the process of adult cell cloning could be used to clone the frozen mouse.
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(3)

(c)     People could ask scientists to use this technique to clone long-dead relatives, whose bodies have been deep-frozen.
Most people would be opposed to cloning a human from a deep-frozen, long-dead relative.
Give one reason why.
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(1)
(Total 6 marks)
 M1.          (i)      DNA        (accept RNA)
for one mark
1
(ii)      DNA carries coded information 
which controls the order of amino acids
in proteins
for 1 mark each
3
[4]
 M2.          (a)     (i)      chromosomes
allow DNA
ignore nucleus
1
(ii)     enzymes
1
(b)     asexual reproduction / no gametes / no fusion / only one parent
ignore clones
1
          cells all contain same genetic information / same genes (as parent) / same DNA
1

(c)     can spray crop with herbicide – only weeds killed
crop survives herbicide insufficient
1

(d)     any one from:
•        fears / lack of knowledge about effects of GM food on health
allow ‘think that GM food is bad for health’
ignore not natural or against religion
•        crop plants may pass on gene to wild plants
•        encourages use of herbicides
1
[6]
 M3.          (i)      DNA
for 1 mark
1
(ii)      contains the code for manufacturing the protein,
as order of bases,
which determine the order in which amino acids are
assembled into protein
for 1 mark each
3
[4]
 M4.          (a)     (i)      sexual / sex
(ii)     egg / gamete / sex cell / ovum      (reject ovule)
for 1 mark each
2
(b)     (i)      meiosis / reduction
(ii)     mitosis / somatic
for 1 mark each
2
(c)     twice as many (reject answers based on 23 / 46 chromosomes)
for one mark
1

(d)     (i)      information / genes / DNA passed from parents
(chromosomes neutral)
for one mark
1
(ii)     genes / genetic information / chromosomes from two parents 
alleles may be different
environmental effect / named may have been mutation
any two for 1 mark each
2
[8]
           (a)     contain the same genes, because they are formed by division
of identical nucleus
for 1 mark each
2
(b)     genes located in nucleus, nucleus comes from donor cells
for 1 mark each
2
(c)     number of alleles in population reduced, therefore less chance of successfully
breeding, to cope with changed conditions
for 1 mark each
3
[7]
 M6.          (a)     
Ampicillin

–
	Tetracycline
–
–

accept blank or cross or –
1st: mark by rows to maximum 3 marks
2nd: if no marks by rows, mark by columns to maximum 1 mark
table completely blank = 0 marks
3

(b)     1st: Yes (no mark)
if ‘no’ - read on for logical argument e.g. loss of plasmid or gene mutation
          2nd: all formed from same original cell
must be one cell i.e. bacterium
1
          by asexual reproduction / no fusion / not sexual
allow reference to ‘mitosis’
1
          offspring cells are genetically identical or
all have a copy of the insulin gene / of the plasmid
1
[6]
M7.          any four from:
•        cells used to treat diseases do not go on to produce a baby
•        produces identical cells for research
•        cells would not be rejected
•        allow cells can form different types of cells
•        (immature) egg contains only genetic information / DNA /
genes / chromosomes from mother or there is only one parent
•        asexual / no mixing of genetic material / no sperm involved /
no fertilisation or chemical causes development
•        baby is a clone
•        reference to ethical / moral / religious issues
allow ethically wrong
NB cloning is illegal gains 2 marks
ignore unnatural
•        risk of damage to the baby
in correct context
[4]
 M8.          idea
•        (gene) in DNA (i.e. mention of DNA)
•        (DNA) contains bases
•        (bases) code for amino acids (in protein)
•        (amino acids) in correct order
•        to make the (spider) protein
any four for 1 mark each
          (No credit for double helix, pairs of bases - but no penalty)
[4]
 M9.          (a)     fusion of gametes / named gametes
allow meet / join / fertilise
1
results in mixing of genetic information / DNA / chromosomes
accept genetic information / DNA / chromosomes from two parents
1
(b)     (i)      use enzyme
1

to cut gene from pout chromosome / DNA
1

insert gene into salmon chromosome / DNA / egg / embryo / nucleus
accept use of plasmid as carrier
ignore salmon / cell
1

(ii)     eg fear of gene transfer to wild salmon / extinction of wild salmon /
fear of harmful effect on consumers / unsure of long term effects
ignore cruel / ethics / morals / religion / unnatural / economics
1
[6]
 M10.          (a)     gene or allele
1
          chromosome
do not credit cell or pancreatic cell or genome
1
          DNA
accept plasmid					1
(b)     any two from
          bacteria grow or reproduce
a growth related point
          DNA ring or plasmid or insulin gene
produced each time
a genetic related point
          insulin gene (in ring instructs bacteria
to) make insulin							2

(c)     any two from
          same match to human insulin
accept animal insulin may be rejected or may not suit humans
          no crossing species risk
accept no risk of BSE type species crossing

          more easy to obtain or can be made in
large quantities
accept it is cheaper to make in the long term or it's quicker
do not credit it’s cheap
          an ethical answer such as no religious
or cultural concerns
accept it is cheaper so can be made available to many more people
2
[7]
 M11.          (a)     because stem cells can (be made) to differentiate
1
into nerve / muscle cells
1
(b)     ethical issues with destruction / damage to embryo
1
(c)     mitosis one cell division, meiosis two cell division
1
cells produced by mitosis have two sets of chromosomes,
cells produced by meiosis have one set of chromosomes
accept cells produced by mitosis are genetically identical, cells produced by meiosis have some genetic differences
1
[5]
 M12.          (i)      any three from:
ignore references to other methods eg tissue culture and embryo transplantation
•        remove gene
•        use of enzymes
•        from plant with high sugar production
allow from bacteria
•        insert gene into rye grass
3

(ii)      any two from eg
•        concern about effect on (health) of cow
•        concern about effects on human (health)
•        concern about food chain effects or effects on ecosystem
•        effect on gene pool
ignore not natural or cost
ignore ethical / religious arguments
if no other marks awarded
‘we don’t know the long term effects’ = 1 mark		2
[5]
 M13.          (a)     any two from
•        copies of chromosomes made
•        cell divides twice or 4 cells formed
•        each gamete / cell now has single set of chromosomes
allow chromosome number halved /
cells haploid / cells n
2
(b)     any two from
•        sex cells / gametes fuse / fertilisation
•        offspring receive genes or chromosomes or alleles from
both parents / DNA
•        alleles in a pair may vary
2
(c)     (i)      new form of gene
allow change in genetic material / DNA / chromosomes / gene
1
(ii)     (no)
         any two from
•        some neutral
•        exemplified
e.g. extra digit
•        some increase chances of survival / reference to natural
selection or evolution
•        exemplified
e.g. example of disease resistance				2
[7]
 M14.         (a)    genetically identical / same DNA / same chromosomes
gains 2 marks
accept identical without reference to genetic material for 1 mark
2
(b)     remove nucleus from egg
allow use empty egg cell
1
insert genetic material / nucleus /DNA / chromosomes from frozen mouse
do not allow if reference to sperm
1
electric shock or allow to divide or insert into womb / uterus			1
(c)     ethical / religious / emotional reasons
not known if it is safe / long term effects not known
ignore playing God / unnatural / immoral			1
[6]
 M15.         (a)    genetically identical / same DNA / same chromosomes
gains 2 marks
accept identical without reference to genetic material for 1 mark
2
(b)     remove nucleus from egg
allow use empty egg cell				1
insert genetic material / nucleus /DNA / chromosomes from frozen mouse
do not allow if reference to sperm				1
electric shock or allow to divide or insert into womb / uterus			1

(c)     ethical / religious / emotional reasons
or
not known if it is safe / long term effects not known
ignore playing God / unnatural / immoral		1
[6