Lecture test 2 (tchr)-1

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Write your Biology class, registration number and name on all the work you hand in. You may use a soft pencil for any diagrams, graphs or rough working. Do not use staples, paper clips, highlighters, glue or correction fluid.
Answer all questions.
For Sections C, the number of marks is given in brackets [ ] at the end of each question or part question.
Section A
For each question there are four possible answers A , B , C and D .
Choose the one you consider correct and record your choice in the boxes below.
Each correct answer will score one mark.
A mark will not be deducted for a wrong answer. Any rough working should be done in this booklet. Calculators may be used. Section
B and C
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This document consists of 5 printed pages.
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NATIONAL JUNIOR COLLEGE, SINGAPORE Senior High 2 Lecture Test 2 Higher 2
CANDIDATE NAME
ANSWERS
BIOLOGY CLASS
REGISTRATION NUMBER
BIOLOGY 9648
06 May 2011 35 minutes
1 Which of the following are reasons for scientists to employ genetic engineering of plant
cloning?
(I) change the phenotype of a plant
(II) create desired genetic changes at a much more rapid pace
(III) produce large amounts of therapeutic proteins
(IV) selective breeding is too slow
A I and II
B III and IV
C II, III and IV
D All of the above
2 What are the possible effects of adding plant growth regulators during
micropropagation?
(I) initiate dedifferentiation of meristematic cells
(II) initiate callus formation from an explant
(III) initiate root formation directly from an explant
(IV) initiate shoot formation directly from a callus
A I and III
B II and III
C II and IV
D All of the above
3 What is the name of the bacterium commonly used as a vector to transform plants cells
that can cause the common crown gall disease?
A Agrobacterium tumefaciens
B Escherichia coli
C Stretococcus aureus
D Saccharomyces cerevisiae
4 Which is not a possible concern of transgenic salmon farming in the ocean using sea
pens?
A Algae blooms
B Escape of farmed salmons to the wild
C Large expense of energy needed to cool down the temperature of water
D Pollution of surrounding water body
5 What is not a consideration when using animals for genetic engineering experiments?
A Animals as sentient beings
B Equal rights for animals and humans
C Overall welfare of the animal species
D Sanctity of life argument
Give reasons or counter-arguments on why the following statements concerning Super Salmon are myths.
MYTH 1: Transgenic salmon in farms grow much larger than wild-type salmon.
Reasons / Counter-arguments:Farmed raised transgenic salmon do not grow much larger but only at a faster rate.
MYTH 2: Transgenic salmon are more susceptible to diseases.
Reasons / Counter-arguments:Transgenic salmons are bred inland, and so less exposed to pathogens.
MYTH 3: Transgenic salmon are voracious predators that will consume all the available food in an ecosystem.
Reasons / Counter-arguments:Transgenic salmons are domesticated and hence may not be able to find food as well as the natural populations.
MYTH 4: Transgenic salmon produce excessive amounts of growth hormone.
Reasons / Counter-arguments:Transgenic salmons do not produce anti-freeze proteins. The anti-freeze promoter is inserted and growth hormone is produced all year round but not excessively.
MYTH 5: Transgenic salmon may out-compete the wild-type salmon due to the large size.
Reasons / Counter-arguments:Larger size of transgenic salmon may hamper their mobility / be made more conspicuous to predators.
Section C
Fig. 1.1 shows the light dependent reactions of photosynthesis that take place on the thylakoid membrane inside a chloroplast.
ATP
synthase
Fig. 1.1
(a) Name the pigment that is represented by P680 and P700. [1]
special chlorophyll a
(Reject: chlorophyll a / chlorophyll / photosynthetic pigment / accessory pigment)
(b) With reference to Fig. 1.1, explain why the pH of the thylakoid space (lumen) is
lower than that of the stroma. [3]
1. lower pH = higher concentration of protons / hydrogen ions / H+
2. photolysis of water in the thylakoid space (lumen)
3. active transport (energy comes from the transport of electrons dow n the
ETC between PS II and PS I)of protons / hydrogen ions / H+from the
stroma, across the thylakoid membrane, into the thylakoid space (lumen)
(c) State the function of the pH gradient across the thylakoid membrane. [1]
stores energy that can be used to drive the endergonic reaction of ATP
synthesis from ADP and P i
(d) Describe the role of NADP red and ATP in photosynthesis. [3]
In the Calvin cycle, NADP red/ reduced NADP / NADPH is used to reduce
1,3-bisphosphoglycerate to glyceraldehyde-3-phosphate.
In the Calvin cycle, ATP is used to phosphorylate 3-phosphoglycerate to
give 1,3-bisphosphoglycerate.
ATP is also used to regenerate ribulose bisphosphate (RuBP) for the
Calvin cycle to continue.
(e) A weed killer called DCMU (dichlorophenyldimethylurea) inhibits electron
transfer in G (the link between E and F). When added to isolated chloroplasts,
DCMU blocked oxygen production. Give an explanation for the observation.
[2]
With electron transfer in G inhibited, P680 in E / PS II would not be
reoxidized to the P680+ state.
Without P680+ to act as an acceptor of electrons from water, no oxygen will
be produced.
[Total: 10 marks]。