14 DSE LS
HKDSE BIO HKDSEHKALE HKCEE
SIR
2014-2015 2


(STSE Connections) (Nature of science,
NOS) 2012-2016 past paper
2016 :

3

20 10

15 (
)
:

+->90
:
1.
(Low-power diagrams)(High-power
diagrams)
(Hypothesis)
(assumptions) (Independent variables) (dependent
variables)(controlled variables)
3. (Nature of science, NOS)
(Nature of science, NOS) 2012 PAPER 1B No. 8c
2013 PAPER1B No. 7d2014 PAPER 1B No. 3b2015 PAPER 1B No. 6d
2016 PAPER 1B No. 8c
:



samples and repeated measurements)
(a) A Name the chemical substance inside A.
(b)


A certain type of food poisoning – botulism – is caused by the ingestion of a bacterial
toxin. This toxin acts by blocking the presynaptic membrane, resulting in muscle
paralysis. Based on this information and features in the micrograph above, explain
how this toxin brings about the paralytic effect.

(a)(Neurotransmitter)
(b)
Toxin blocks the release of the neurotransmitter into the cleft

Nerve impulses cannot be transmitted across the neuromuscular junction to stimulate

8

:


/



1

0

(:())
:
explain)


D. (1)(2) (3)
( :B 1 DNA 4N 2
DNA 2N 3
DNA 4N)
(Glycolysis) ATP )
A O A .
()
(1) (homozygous)
(2) (homozygous)
(3) (homozygous)
D. (1)(2) (3)
(homozygous))
(Photosynthesis)(Respiration)


(Nature of science, NOS)(Scientific Inquiry) PAST
PAPER