Ch 15 Detecting the environment Exercise - Bio-662

New Senior Secondary Mastering Biology (Second Edition)
Book 2
Ch 15 Detecting the environment
Multiple-choice questions (p. 15-41)
1 B
6 A
11 C
5 C
10 D
Short questions (p. 15-43)
12 HKDSE Biology Practice Paper 2012 IB Q3
(a) Retina* (1)
(b) Photoreceptor A cannot distinguish colours (1)
while photoreceptor B is responsible for colour vision. (1)
Photoreceptor B is only stimulated by strong light, and (1)
a larger number of photoreceptor B is stimulated in bright light than in dim light. / a
smaller number of photoreceptor B is stimulated in dim light. (1)
Thus the coloured object is perceived as being more colourful in bright light.
13 The ciliary muscles contract. (1)
The suspensory ligaments become slackened. (1)
The lens becomes more convex. (1)
14 a
B (1)
F and G (1)
iii B to C / from 1.9 to 3.3 minutes (1)
The ciliary muscles relax. /
The suspensory ligaments are pulled. /
The suspensory ligaments pull on the lens. /
The lens is elastic. /
The lens becomes less convex / thinner.
(any 4) (1) × 4
15 a
Auxin from the coleoptile tip diffuses into the agar block, (1)
causing growth / cell elongation of the decapitated coleoptile. (1)
b There is a positive correlation between the time that the tip was left on the agar
block and the growth of the coleoptile. (1)
With increased time, more hormone can diffuse into the agar block / more hormone
is available for cell elongation. (1)
The result levels off as the agar block can only hold a limited amount of the
hormone / as there is a limit to how much a cell can elongate. (1)
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New Senior Secondary Mastering Biology (Second Edition)
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c The agar blocks contain different amounts of hormone. / The quality of contact
between the agar block and the decapitated tip varies. / Hormone diffuses more
readily in some decapitated coleoptiles than others. / Some tips have more hormone
than others. / There is variation in the quality of coleoptile.
(or other reasonable answers) (1)
a Correct drawing to show the coleoptile placed with block D is shorter than the
others (1)
b The agar blocks received auxin from the tips. / Auxin moved from agar blocks into
the decapitated coleoptiles. / The metal sheet prevented lateral movement of auxin. /
Auxin stimulated cell elongation. /
Blocks A and B produced the same growth as auxin had diffused equally into
blocks A and B because the light was from above. /
Block C produced more growth as more auxin was available. / Block D produced
the least growth as least auxin was available. /
Most auxin diffused down the shaded side. / Less auxin diffused down the
illuminated side.
(any 4) (1) × 4
c Blocks A and B allowed comparison / act as a control experiment. / To show that
the growth stimulus (production of auxin) was even when light was from above. / To
confirm that lateral illumination influenced the movement of auxin. (1)
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New Senior Secondary Mastering Biology (Second Edition)
Book 2
Structured questions (p. 15-45)
17 HKCEE Biology 2007 I Q7a
(i) *ciliary muscles (1)
(ii) when the man is looking at a near object the weakened ciliary muscle contract with
less force (1)
and the tension of the suspensory ligament remains high (1)
Hence, the lens is not thick enough (1)
and fails to converge light to form a clear image on the retina (1)
Effective Communication (C) (1)
(b) The lens becomes less elastic /cloudy (1)
(c) Layer B contains light sensitive cells (1)
cannot obtain nutrients / oxygen from layer C (1) +
As a result, light sensitive (retinal) cells die (1)
Light falling on layer B cannot be detected /no nerve impulse can be produced (1)
Therefore the vision is impaired.
Total: 10+1 marks
18 HKCEE Biology 2010 I Q5
(i) Cone (1)
(ii) Vision in the centre mainly relies on the detection of light falling on the yellow spot.
As the yellow spot contains cone cells only, light falling on this spot can hardly be
detected by the patient with this disease. (1)
The vision becomes blurred in the centre.
Effective Communication (C) (1)
(i) The use of the bionic eyes replaces the normal light path through the lenses (1)
for image formation.
(ii) Yes
Signals from the camera are sent to the device which stimulate the optic nerve
directly / Light-sensitive cells are not required for the stimulation of optic nerve (2)
or 0
(1) * Cerebrum/ * cerebral cortex/ * sensory area/ * visual area (1)
(2) This type of bionic eye can give visual sensation to a person with damage in
optic nerve / rupture of eyeball / no eyeball (1)
Total: 8+1 marks
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New Senior Secondary Mastering Biology (Second Edition)
Book 2
19 a
Label ‘V’ on oval window (1) and round window (1)
Label ‘X’ on cochlea (1)
d Part D is the passage to the air outside / to the atmosphere / to the throat, (1)
so as to equalize the pressure between the middle ear and the atmosphere. (1)
Blockage of part D causes the pressure on both sides of the eardrum to become
unequal, so the eardrum bulges. (1)
The eardrum cannot vibrate and sound waves cannot be transmitted to the middle
ear. (1)
20 HKCEE Biology 2002 I Q4a
(a) The loudness of the sound heard would be smaller. (1)
because A is used for collecting sound waves into the external ear canal / less sound
waves are collected. (+1)
(b) C, E and F (2) (3 answers correct, 2 marks; 2 answers correct, 1 mark)
(i) * cochlea (1)
(ii) They serve as receptors to detect sound vibrations / They are stimulated by sound
vibrations. (1)
and they produce nerve impulses upon receiving the vibrations. (1)
(d) Due to the frequent loud noises, the sensory hair cells are over-stimulated (1)
so they are damaged / become fewer in number (1)
(e) Hearing will be lost (1)
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New Senior Secondary Mastering Biology (Second Edition)
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because D, being damaged, cannot transmit nerve impulses to the cerebrum (1)
where the nerve impulses are interpreted into hearing (1)
Effective communication (C) (1)
Total: 12+1 marks
21 HKDSE Biology 2013 IB Q7
(a) the tip is responsible for detecting the unilateral light (1)
because if it is removed / blocked from the stimulus, no bending growth
movement occurs (1)
on the other hand, the same response is produced even if the lower part of the
coleoptile is covered in soil. (1)
(b) to show that the failure to produce response in set-up II is not due to the effect of
injury / damage when the tip is removed (1)
(c) some substances are produced from the tip of the coleoptiles (1)
which can diffuse through the agar block (1) to reach the lower part of the
and exert effect / lead to bending growth at the lower part of the coleoptile (1)
Science is based on ✓ Both Darwin and Jensen used the results from their experiment to
(1) develop their understanding about phototropism in plants (1)
Science knowledge
Darwin’s work only provided some understanding about
is tentative and
phototropism and Jensen’s results helped develop further the
science knowledge (1)
(11 marks)
22 a
Each section grows by a very small amount. /
Combined growth is easier to observe / measure. /
This can reduce experimental errors / improve accuracy.
(any 2) (1) × 2
The metal weight applies constant force for the coleoptiles to act against. /
The metal weight does not transmit light / casts shadow on the film. /
The metal weight stops coleoptile sections from floating up. / Metal does not float.
(any 2) (1) × 2
The coleoptiles grow in length and push the weight up. (1)
So the shadow on the film rises. / So more light is blocked. (1)
d IAA causes an increase in growth rate of coleoptiles. /
There is time delay in the effect. /
Softening of the cell wall allows expansion of cells / of vacuoles due to the uptake
of water / fluid. /
Soft cell walls allow mitosis / cell division. /
Therefore the length of the coleoptile increases.
(any 3) (1) × 3
e Temperature, because it affects the rate of enzyme action / metabolism. /
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The strain / age / growth conditions of the coleoptiles before the experiment, so the
cells are in similar stage of expansion / growth. /
Where sections are taken from in the coleoptiles, so the cells are at similar stages of
differentiation / have similar hardening of cell walls. /
The mass of the metal weight, so as to provide a constant force.
(any 2) (1) × 2
f Small movements of weight lead to a much larger movement of the shadow on the
film. / To put the scale on the axis. / To convert the beam movement to mm of growth
/ to give a quantitative result. (1)
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New Senior Secondary Mastering Biology (Second Edition)
Book 2
Essay (p. 15-48)
23 HKALE Biology 2011 II Q4a
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 Oxford University Press 2014
New Senior Secondary Mastering Biology (Second Edition)
Book 2
Reading to learn (p. 15-49)
The photoreceptors in the retina detect light (1)
and generate nerve impulses which are sent to the brain for interpretation. (1)
Conjunctiva, cornea and lens. (3)
Blindness due to damaged retina (1)
or non-functioning photoreceptors. (1)
It cannot restore eyesight in people who are blind due to damages to the optic nerve or the
visual centre of the brain. /
It can only restore vision partially. /
It requires surgical operation which may not be suitable for all patients especially the
elderly. /
It may not be functional for a lifetime.
(any 2 or other reasonable answers) (1) × 2
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