1.

A researcher used a vector X to insert a foreign gene to create a

recombinant vector. The image of vector X is shown below.

It has sites for two restriction enzymes - SacI and EcoRI. The foreign
gene can be cut using either of these two enzymes. The vector also
has a green fluorescent protein (gfp) gene that can be used as a
selectable marker, and two genes - chloramphenicol resistance (CmR)
and neomycin resistance (NeoR) that provide antibiotic resistance.
Chloramphenicol and neomycin are two different
antibiotics.
(a) What is/are the possible end product(s) that will be obtained post-
ligation if the researcher uses the following enzyme to insert the
foreign gene:
(i) SacI
(ii) EcoRI
(b) Based on (a), which enzyme will be better to use to ensure that the
foreign gene has been inserted in the vector? Why?
(c) If the well of an agarose gel is filled with a solution of the intact
vector and the foreign gene, what will the DNA band closer to the
well contain? Why?

2. The large-scale production of an organism is generally done in a

bio-processor unit. Given below is the growth curve of a
bacteria that is being used for the production of a recombinant
 molecule. Maintaining sterile conditions is of utmost importance
in a bio-processor unit.

(a) In which phase are the cells likely to be producing a larger

concentration of the recombinant molecule? Why?
(b) In cases where the culture in the bio-processor unit reaches the
death phase, identify ONE strategy that can help revive the bio-
processing to restart production of the recombinant molecule.
(c) What does a sterile condition mean?
(d) State ONE reason why the bacteria that are producing the
recombinant molecule are not harmed during the process of
sterilisation.

3. Bacterial cells offer certain advantages over plant or animal cells

that make them an easy choice for the production of many
recombinant molecules. State THREE such advantages.

4. pBR322 was a plasmid that was constructed artificially using

genetic material from three sources:
i) the tetracycline resistance gene of pSC101
ii) the ampicillin resistance gene of RSF 2124
iii) the replication elements of pMB1, a close relative of the ColE1
plasmid.
Describe the TWO enzymatic steps that would have occurred in the
construction
of pBR322.
 5. The basis of rDNA technology is to alter the genetic material of
an organism to obtain enhanced and desired characteristics in an
organism.
(a) Preferably, the gene of interest and the vector are cut with the
same restriction enzyme. Is this statement true? Give a reason to
support your answer.
(b) What is/are ALL the possible outcomes after the gene of interest
and the vectors are ligated?
(c) If a vector contains an ampicillin resistance gene as the selectable
marker, state TWO situations in which the host cell will not grow in a
medium that contains ampicillin.

6. State whether each of these statements given below is/are true or

false. Justify your answer.
(a) Plasmids with a single restriction site are preferred over those with
multiple sites for the same enzyme during the cloning process.
(b) The tumour-inducing (Ti) plasmid can be extracted from
Agrobacterium tumifaciens cells and used as it is for cloning a foreign
gene.

7. Vectors containing the foreign DNA have to be forced into host

cells that are made competent to do so. A common method is to
first treat host cells with calcium chloride and then incubate
these cells on ice. This is followed by briefly placing them at 42
°C and then putting them back on ice. This enables the host cells
to take up recombinant DNA and is called the heat shock
treatment.
(a) Explain why DNA vectors CANNOT pass through the cell
membrane like other molecules such as oxygen.
(b) Calcium from a CaCl2 solution binds to DNA making it easier for
them to enter a cell. Why?
(c) Why does the heat shock treatment make the membrane porous
allowing for easy uptake of DNA?

8. Given below is an image of a hormone which is required for the

treatment of a
disease.

(a) Identify the hormone and the disease that is caused due to its
insufficient secretion.
(b) State whether the following statement about this hormone is true
or false. Justify if true, correct if false.
'The structure in the image is a protein and is the precursor form of
the hormone.'
(c) Which characteristic helped you arrive at your answer in (b)?
(d) Describe the challenge in large scale production of this hormone
using rDNA techniques and how it was overcome.

9. According to recent reports, MIT engineers have embedded

genes from fireflies into watercress plants inducing them to give
dim light for nearly four hours. To create these plants, the MIT
team turned to luciferase, the enzyme that gives fireflies their
glow. Luciferase acts on a molecule called luciferin, causing it
to emit light. Another molecule called co-enzyme A helps the
process by enhancing luciferase activity. None of these
molecules are naturally produced by plants.
(a) Describe briefly, the step-by-step process that should be followed
in creating these plants.
(b) Draw a diagram of the possible vector used in (a).

10. The plasmid shown below is 7866 base pairs in length and
contains genes that confer resistance to antibiotics tetracycline
and ampicillin. The bp at which the restriction site is present is
also shown.

(a)While working in the lab, Reema took three individual samples

of the plasmid. She added different restriction enzymes, EcoRI,
HindIII, and BamHI, separately in each of the samples. But she
forgot to label the samples in a hurry. She ran the three digested
samples on an agarose gel electrophoresis to see the fragments.
The results are shown below:
 Considering complete restriction digestion had happened, help
her identify which sample is digested by what enzyme.
(b) Next, Seema digested a target DNA with HindIII, and
ligated it with plasmids digested with the same enzyme and
transferred them into a bacterial cell. How will she distinguish
the transformant with recombinant plasmid from
nontransformant? Give a reason to support your answer.

11. A culture plate of Lactobacillus shows blue-coloured

colonies and colourless colonies. Explain the principle involved
in the formation of such variance in the colour of colonies.

12.
 13. Explain how advent of biotechnology has helped in
preventing infestation by nematodes and thereby increasing crop
yield.

OR
14. In the future, genetic therapies may be used to prevent,
treat, or cure certain inherited disorders in humans. Justify the
statement with a suitable example.

15.

What will be the impact if oriin the above structure gets damaged?
b) The lac z gene has many recognition sites. Study the segment of
DNA given below and answer the questions

5’... ATC GTA AAG CTT CAT…3’

3’... TAG CAT TTC GAA GTA…5’
i) Applying your knowledge of palindrome sequences identify
and mark the possible region where the restriction enzyme X
will act.
ii) Restriction enzyme Y was used to extract gene of interest
from a plant. This gene needs to be inserted in the given DNA
segment which has been treated with restriction enzyme X.
Will there be a successful recombination? Explain with a
reason.
iii) Which one of the two (pUC18 and pBR322) would you
prefer for biotechnological studies? Justify.

16. A farmer grew 2 varieties of corn crop in field A and B. He

grew normal corn crops in field A and GM corn crops in field B.
He observed corn borers attacked only in field A. To control it,
spores of Bt were sprayed in field A. a) Name the gene in the
spores responsible for the control of this pest. b) What effect
will the spores of Bt have on the insect pest? c) How has field B
developed resistance against this pest?

17. Lipoprotein lipase deficiency (LPLD)is a genetic disorder

in which a person has a defective gene for lipase. This leads to
high triglycerides, stomach pain, fat deposits under the skin. It
may eventually affect the liver, pancreas and may also cause
diabetes. The disorder occurs if a child acquires defective genes
from both parents (autosomal recessive). ERT (enzyme
replacement treatment) is one of the treatments offered to
patients with LPLD.

a) (i) What procedure is followed in ERT?

b) (ii) What could be one possible drawback of ERT?
c) How can LPLD be treated using Biotechnology? Elaborate.
 18. Oil spill is a major environmental issue. It has been found
that different strains of Pseudomonas bacteria have genes to
break down the four major groups of hydrocarbons in oil. Trials
are underway to use different biotechnological tools to
incorporate these genes and create a genetically engineered
strain of Pseudomonas - a ‘super-bug’, to break down the four
major groups of hydrocarbons in oil. Such bacteria might be
sprayed onto surfaces polluted with oil to clean thin films of oil.
(a) List two advantages of using bacteria for such
biotechnological studies?
(b) For amplification of the gene of interest PCR was carried
out. The PCR was run with the help of polymerase which was
functional only at a very low temperature. How will this impact
the efficiency of the PCR? Justify.
(c) If such bacteria are sprayed on water bodies with oil spills,
how will this have a positive or negative effect on the
environment? Discuss.

19. Shown below is a cloning vector 'Z' that Kamla wants to

use to create a recombinant vector with her gene of interest.

The vector consists of sites for three restriction enzymes - ScaI,

HindIII and EcoRI. Restriction sites for the same enzymes are also
present in the gene of interest. There are two 'ori' sequences - one
allows it to replicate in Escherichia coli and another allows replication
in Zymomonas mobilis. Apart from this, the vector consists of two
antibiotic resistance genes - one against tetracycline (tet) and another
against chloramphenicol (cml).
(a)If the vector was cut using Hind III, what would colonies
growing on a medium containing tetracycline definitely contain?
(b) Suggest which of the three restriction enzymes would be
suitable for insertion of the gene of interest. Give two
advantages of using the enzyme chosen by you.
State one disadvantage of using the other two restriction enzymes not
chosen in (b).

20. Insects in the Lepidopteran group lay eggs on maize crops.

The larvae on hatching feed on maize leaf and tender cob. In
order to arrest the spread of three such Lepidopteran pests, Bt
maize crops were introduced in an experimental field. A study
was carried out to see which of the three species of lepidopteran
pests was most susceptible to Bt genes and its product. The
lepidopteran pests were allowed to feed on the same Bt-maize
crops grown on 5 fields (A-E). The graph below shows the leaf
area damaged by these three pests after feeding on maize leaves
for five days.
Insect gut pH was recorded as 10, 8 and 6 respectively for Species I,
II and III respectively.
(a)Evaluate the efficacy of the Bt crop on the feeding habits of the
three species of stem borer and suggest which species is least
susceptible to Bt toxin.
(b) Which species is the source organism for the Bt gene?
(c)How does it not harm the source from which it is taken?
OR
(c) Using the given information, suggest why similar effect was
not seen in the three insect species?