頁四第張六第日一初月九年申庚歷夏
1981
中學會考試題預習專欄
生
物
明德出版社梁永華提供資料
BIOLOGY (1)
W、 W. Leung
MILL & DALE PRESS LTD.
Unit 1: NUTRITION.
1. The table below shows the minimum daily requirement
of a number đó nutrients, together with a list of some of the things present in cow's milk.
Food' energy
Proteia
Iron
Daily
Tax an
réquirement.
Present
in 100.
11500: KJ
cowi Ik
276 KJ
3.38
WAH KIU YAT PO
(b) Cow's milk is deficient
in iron and vitamin B
(c) Deficiency in iron and
vitamin B would cause anemia and beri-berif dermatitis respectively.
Vitamin D..
It is because vitamin D. can be produced by the skin under the action. of the ultraviolet light.
(e) Roughage.
2.(a) Enzyme A breaks down
insoluble egg-white protein into soluble products.
(b) (1)
20
Enzyme activity
(x-y) m
30 min
10
Calefu
Vitamin A
Vitamin B
Vitamin C
Vitamin D
80.2 12:0 g
08
5000 iu 13.7 mg.
20
0,03 g
0
4
9. 10
0.128
150-in
0.27.og
2 g
2.iu
(a) If a man puts himself on
a diet of cow's milk, calaulate the weight of milk required to provide enough energy for him per day.
(b) Why would a diet of cow's milk be inadequate for man?
(c) Name two deficiency
diseases as a result of (b).
(d) Which of the vitamins
would not necessarily be
present in our food? Why?
(e) Give an important
component of mammal's
food, which is absent in cow's milk..
The following diagram
shows the method to
investigate the activity
of enzyme A.
37°C | 30 mín
boiled egg white
buffer solution
enzyme aÅ
glass tube
The effect of pH on enzyme activity can be investigated by using buffer solutions of different pH values. The results are recorde As shown in the followin table.
pil of the
X
Y
buffer solution (mm) (1)
35
1.0
37
36
35
33
(a) Describe the function of
enzyme A.
(b) (1) Using the above data
plot a graph with
enzyme activity' a the vertical axis and
pH as the
horizontal axis.
(2) What is the optimum pH for the activity of enzyme A?
(3) Give a possible
activation for the activity of enzyme1⁄4À at pil 10;
(c) Suggest an enzyme in our
alimentary canel, which has properties similar to enzyme A. Give reasons for your suggestion.
ANSWERS
1.(a) 11500 X 100
276
@
(2) The optimum pH
determined in this experiment is pH 2 (3) Enzyme A does not
-function at pH 10, perhaps the enzyme protein is t
inactivated or
denatured in such alkaline solution:
Pepsin.
Pepsin is a gastric enzyme which digests
protein and acts best at pll 2.
1981
中學會考試題預習專欄
地理
明德出版社李婉儀提供資料
GEOGRAPHY (1).
1. Y. Lee
MILL & DALE PRESS LTD.
series of exercises is to
help you to get aā
much better
result in the Geography Paper
of the School Certificate Examination. Two essay type questions are each time, with suggestive model answers. They aim at supplying supplementary information as well as providing revision for you. To acquire the optimum bebefit, students are advised to think of the points carefully by themselves first bofore reading the model answers, The questions are 90 carefully set that they covering almost every item of
Jon Syllabus, not only give
you ample
also help you evaluate your ability to observe accurately, interpret systematically and present your ideas logically.
Revisional Questions:
1. If you were given the task
of setting up a school weather station to measure * relative air temperatures". humidity and rainfall amounts, what would you buy?. How would you set them out? Draw well1-Tabelled diagram to illustrate your answer
Suggested Answers: 1.8.
Air temperatures. To measure air.
temperatures, the following instruments should
be bought:
1) An ordinary mercury
thermometer to measure current air temperature or the temperature at a
particular time,
Maximum thermometer to nca sure maximum temp Minimum thermometer to measure minimum temp. DIAGRAMS TO SHOW THE THREE TYPES OF THERMOMETERS Mercury thermometer
Bulk
Mercury in
Maximum thermometer with constriction
Constriction Mer
4167 (c)
・Break in mer
tirend
報日僑華
Maximum thermometers with ・metal index
•Max. T":
Merc
Métal index
Minimum thermometer
Alcohei
Metal inder
Procedure of Setting Up
四期星
1) All the above instruments
should be housed
horizontally in a Stevenson Screen.
2) This is done since shaded
temperatures are required. 3) The Stevenson Screen is a
wooden box whose roof is
air double boarded with an space between so that the heating effect of the sun can be minimized.
The louvred sides allow the air to move freely so that the air inside the acreen has the same characteristics as the air
outside.
5) The screen is painted white
to improve insolation.
6) The screen is mounted on a
stand to avoid heat
reflecting from the ground. from influencing the thermometers directly. ·
7) It should be positioned in
the most open and exposed place with its door opening to the north to prevent the sun from
shining into the screen whilst readings are being
taken.
The readings should be recorded daily at a fixed time, preferrable in the morning. After recording, the maximum thermometer should be reset by using a magnet (for the one with a metal index) or by shaking
vigorously (for that with
a constriction) and the minimum thermometer should. be reset by tilting it gently,
b. Relative humidity
To measure relative.
humidity, a wet-bulb "and dry-bulb thermometer should. be bought.
VET-BULB AND DRY-BULB THERMOMETER
Dry-bulb thermometer
Mercury.
Wet-bulb thermometer
Procedure of Setting Up 1) It should be housed in the
Stevenson Screen, too,
2) The bulb of the wet-bulb
thermometer should be kept moist all the time by covering it with muslin which dips into a container of water.
3) The difference between the
two readings is an indicator of the humidity of the air:
if there is no difference the air is saturated if the difference is large
humidity is low if the difference is small
humidity is high The actual value of relative humidity is obtained by checking the reading from a book of tables.
Amounts of Rainfall
"To measure the amount of rainfall, a rain gauge necessary.
A RAIN GAUGE
Funnel
~Copper cylinder.
Glass bottle
Outer capper case
Procedure of Setting Up
In setting up the rain gauge, the following points must be noted:
) It must be put on level
ground.
2) It must be placed in an
exposed position, far away from any objects which might affect the amount of rainfall collected. If the
日九月十年〇八九一圈公年九十六國民華中育教儁輩
buildings and trees are present, the gauge must be positioned away from them
at a distance of at least twice the height of these objects.
3) It must be sunk in the
ground to prevent it from being blown or knocked
over.
4) The top of the funnel must
be 30.8cm (12") above ground-level, to prevent rain nearby splashing inte the jar.
2. Below are diagrams showing
information of rainfall in Hong Kong. With the aid of
for the diagram, account seasonal and geographical distributions. of rainfall in Hong Kong.
Fig.I RAINFALL DISTRIBUTION
OF HONG KONG
Over 2500mm 1760-2000
7 2000-2250mm 69 below 1750mm
Fig. II TEMPERATURES &
RAINFALL OF HONG KONG
JÉMAMIJAS OND
Suggested Answers::
2. The Seasonal Distribution of Rainfall in Hong Kong
From the Climatic: graph,
ve can see that the rainfall annual in Hong Kong, with an total of about 200 – 2500. mm,
does not distribute evenly. About 80% of the rain occurs
from in the summer months - May to Sept. A monthly total of over 250 mm in the summer rainy season is not uncommon. While in winter, it is
relatively dry.
The summer maximum of rainfall in Hong Kong can Partly be explained by the influence of monsoons. Hong Kong lies in the Asian monsoonal wind belt, în summer, a low pressure belt is formed over Mongolia, while a high pressure belt is found over the sea. As a result, the wind blow inland from the sea. They are therefore moist and they bring heavy rain to Hong Kong In winter, the winds blow offshore because the low pressure over Mongolia is by now replaced a high pressure system. Thus the winds that influence Hong Kong are quite dry (Fig. Fig. A THE SUMMER MONSOON
OF ASIA
INTENSE
HORSE AT HIGH)
DOLORUM
Besides the monsoons, the seasonal distribution of rainfall in Hong Kong is also greatly affected by typhoons. The typhoons, which attack Hong Kong mostly from May to Sept, are always accompanied by torrential rain (Fig. B). Fig.B MAIN TYPHOON TRACKS IN THE WEST PACIFIC OCEAN
Whast of the
Arogical
formed to
the
Furthermore, the high summer temperatures in Hong Kong (with an average around 27 C) are likely to induce rainfall too. When the land surfaces are overheated, strong vertical air currents set up. As the air ascends, its temperature is reduced until condensation takes place and clouds are formed. The water droplets in
clouds will become bigger with further ascept, which meaus further cooling, In time the water droplets in clouds become too big and heavy to be saturated, rain
egins to fall, This type of rain is known as convectional rainfall. Hong Kong, being situated in the tropical latitudes, the convectional rainfall is especially characteristic in summer (Fig. C).
Fig.C FORMATION GE
CONVECTIONAL RAINFALL
DESCENDING
COOLER PENSER AIR
cloyd's
RAIN
GRISING WARM AIRL
the sun
and surface heated.
The Geographical
Distribution of Rainfall in Hong Kong
Fig II is the annual rainfall map of Hong Kong. The map shows that the areas with muximum rainfall (over 2200mm) coincide with highland areas, e.g. Tai Mo Shan region and Lantao Shan region.
The areas with the lowest amount of rainfall (below (1800mm) lies on the weat,
the northwest lowland around Deep Bay, the southwest of Lantao Island and the Tsing.. YI Island. Such a geographic distribution indicates an orographic effect. This is because, as mentioned above; most of the rain in Hong Kong is brought by onshore monsoons which blow mainly in an easterly direction from the
sea. As the moXAMS,
winds meet the
they will be forced to rise, They are then cooled, condensation thus, occurs and clouds are formed. Being subjected to much the same process as those in the rising air currents as heated, water droplets fall down at last, Thus the mountain regiona, especially the east-facing alopes in Hong Kong, have more rain because of this orographic effect. By the time the winds reach the lowlying western part, they are depleted of moisture. As they descent the leeward slopes, they are wormed by compression Consequently, there is little rain and these areas are referred to as rain shadow areas (Fig. D).
Fig.D THE FORMATION OF
OROGRPHIC (relief) RAIN
∙As air ascends, it becomes cooler.. ・and saturated:
R.H. rises
Wind ward slope
As air descends
1st compressed
and becomes
Warmer
B.H. falla
RAIN.
SHADOW
Leeward slope
Mountain
mass