四期星

one million people in South East Asia.

頁二第張六第日四廿月二十年申庚服夏

1981

WAH: KIU YAT PO

報日僑華

i/ Equatorial rain foresi

The forests are rich

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明德出版社李婉備提供資料

Géography (17)

Y. Y. Lee

MILL & DALE. PRESS LTD.

33. The following passages describe three different. types of natural vegetation: (1) The forests are rich in

the variety of trees. They are evergreen in appearance because, although individual trees shed their leaves at intervals, new leaves are always growing on others. Trees, form three or more layers of growth, with the tallest species attaining 50 metres or more. There is a lack of undergrowth except along river banks and near the edge of the forests.

(2) The vegetation consists

chiefly of low, thorny. deciduous trees or bushes, and drought-resistant shrubs and herbs. Many of them have long, deep and branching roots. Others may have fibrous tissues, waxy surfaces. or sunken stomata. The seeds may lie dormant for years and rapidly germinate and bloom when favourable conditions are available. (3) The vegetation consists

mainly of softwood trees, occurring in pure stands. The leaves of the trees are needle-shaped and last for several years. Beneath the forest cover are various shrubs, ferns and mosses. Name the three types of natural vegetation describe above.

b. Using the letter symbols given in Figure, indicate one aréa of occurrence for each type of vegetation mentioned within the area shown in figure.

c. Choose any Two types of

vegetation mentioned, and explain separately how they adapt to their climatic environment.

Suggested Answers:

a. The three types of natural

vegetation:

1/ Equatorial rain forest or

tropical rain forest, ii/ Desert or arid type

vegetation. iii/Coniferous forests or cold temperate forest. b.Occurrence of the forests Eequatorial rain forest

H desert vegetation

coniferous forests

B

c. Ways to adapt to their climatic environment,

and luxurant. Because of the ideal climatic

conditions- with high

temperatures and abundant rainfall throughout the year,

the growth of trees is rapid. As there is no dry season, the trees are evergreen. The trees are tall and

straight. The branches and leaves appear near the crown so as to complete for light and air. The leaves are broad with driptips, or glossy or leathery, so as to shed rain-water or to enable efficient photosynthesis. The height of the trees requires the development of large buttress roots for support. Many of the tall trees are used by climbing plants, which are also striving to win light or air, or are parasitic for nutrition. There is very little undergrowth except along river banks, because very little light can penitrate the thick foliage to reach the floor, In Swampy area where the ground is boggy, the roots. are strong and long to support the plants well above the water. In some cases, the roots are aerating for breathing purpose. There is a lack of undergrowth for the absence of light.

ii/ Desert vegetation

Because of the aridity in the desert, the plants are drought resistant known as xerophytes. The plants are usually low. Some of the plants have deep and branched roots to penetrate under-ground in search of water supplies. They develop waxy or thorny leaves, some with sunken stomata to reduce transpiration. Some of the plants have wax covered fleshy stems to store water. Some plants have. widespread net-work of surface roots to absorb. dew moisture. Some plants remain dormant for years awaiting the infrequent rain showers. Their seeds are protected by an impervious coat. Immediately after rain, the seeds germinate and bloom, rapidly complete their life-cycle before dying down. Some plants, which are known as halophilous, can thrive on areas of saline soils.

iii Coniferous forest

a. Briefly describe any

common features of location, origin and function, noting any exceptions.

b. What are the common

problems of such cities of the developing world?

RANGOON

BANGKOK

BANDUN

DJAKARYA

SURABAJA

Suggested Answers:

*Cities, with aver

one million people

a. Common features of the

cities.

The cities marked on the map have the following features. in common:. Location - In general, they have a coastal or esturine location, commanding the important world's shipping routes. The only exception is Bandung, which is located in the uplands of western Java. Most of them have rich hinterlands. Origin -- Most of them have

long history of development started from the Colonial Period, i.e., many of them had been colonized by western powers, with the only exception of Bangkok. Despite the long history of development, many of them experienced rapid development recently, which may also be resulted from rural-urban migration.

Function -- Most of them are good ports, with the only exception at Bandung. Besides serving as good ports, most of them are multi-functional. A good example to be cited is Manila, which is a commercial centre, industrial centre, route focus and administrative centre as well. Most of them are well-known as they are capital cities, except Bandung and Surabaja.

b. Problems of such cities of

the developing world.

“་་

The trees are usually conically shaped, with springy or downward sloping branches to prevent excessive accumulation of snow. Since there is low precipitation in the cold temperate region, the bark of the trees is usually thick thick, their leaves are needle shaped so that loss of moisture by transpiration can be

reduced. Moreover, the leaves are usually covered by wax to protect against frost damage. Tree trunks are flexible and slender, so that they can stand well against the strong winds. Roots are usually shallow and widespread, that allow the trees to absorb water above the frozen sub-soil. The seeds are usually protected in cones to suit the severs coldness." 34. Study the figure below which shows the cities with over

Due to the rapid urban growth, overpopulation is the major problem. Food is not enough and malnutrition is

common.

Housing is another problem. In such cities of the.. developing world, there are usually many squatiers and slums. Over-crowding in urban areas forces the dwellers to live in unhygenic conditions.

Sanitation is poor not only because of over-crowdiness, but also because of the lack of the water supply and inadequate. waste disposal. Residential land use is found mixed with industrial ones, the discharge of gas, smog and other wastes by factories and vehicles.

results in air pollution, water pollution and sound pollution, Such areas are also a safety hazard, fire is most likely

to occur.

Since the narrow streets of the cities constructed in the colonial periods are not able to cope with the increased traffic flow, traffic congestion and accidents pose another problem.

Problem of

unemployment is also serious The education of the people is usually low. Many of them are unemployed. Social problems such as crimes arise. Owing to the same reason,

日九廿月一年一八九一座公年十七國民鞌中有数据

stration is difficult,

They are usually areas

of political unrest. There is

also a lack of general utilities,

e. g. schools, hospitals and recreational facilities.

(十七)

明德出版社梁永籤提供資料 Biology (17)

W. W. Leung

MILL & DALE PRESS LTD.

General Revision

1. The following figure shows

the growth of an annual plant.

Dry Wt.

(adult frog)

Time

(a) What is the advantage of

using the dry weight as a measure of plant growth? (b) Describe and explain the

change in dry weight of the plant

(1) at period A

(2) at period B.

(c) At which period does the

plant begin to disperse its fruit ?

(d) The growth curve of a frog

from egg stage to adult stage resembles the curve shown

above.

(1) Describe and explain the

change in dry weight at period A.

(2) What process takes place

at the end of period A? (3) Name the developmental

stage of the frog at period B

(4) Describe and explain the

change in dry weight at period C.

2. The following table shows the osmotic pressure at different times of day measured within. the guard cells of a plant.

Time

Osmotic pressure

7a, m. 11a.m.

5p. m.

12 midnight

(kilograms/cm2)

15

32

19

13

The osmotic pressure of the other lower epidermal cells remains constant at 11kilograms/cm during this experiment,

(a)(1) Refer to the table only, at

what time do the guard cells show the highest turgidity?

(2) At this time, what

appearance would you expect the guard cells to

I have?

(3) How is such appearance

advantageous to the plant? (b) Describe and explain the

flow of water occuring between the guard cells and the surrounding epidermal cells from 7a, m. to 11a.m. (c) Explain how the osmotic

pressure of the guard cells is lowered from 5p. m. to 12 midnight,

(d) If the plant was placed in a

glass chamber containing a dish of sodium hydroxide. solution at 11a.m., the osmotic pressure of the guard cells measured at 5. p. m. would be found to have little change. Explain the reason for this. Suggested Answers:

1. (a) Dry weight measures the

actural changes in plant materials during growth. Any changes in weight gain for water loss can be.

avoided.

(b) (1) At period A,” the dry

weight of the plant decreases with time.

This is a germination stage at which the plant

cannot manufacture.

food substances by

photosynthesis, Food

reserves are used for

respiration to release

energy for the

development. The plant

materials are lost in

the forms of water and

carbon dioxide.

(2) At period B, the dry

weight of the plant increases with time. Green leaves appear at this stage and food substances can be manufactured by photosynthesis to support the growth. The dry weight of the plant increases as plant materials are accumulated during this period.

(c) Period C.

(d) (1) The frog is in an egg

stage at period A. The dry weight of the egg decreases with time because food reserves are used for respiration to release energy to support the initial development. The egg materials are lost in the forms of carbon dioxide, water and soluble nitrogenous compounds.

(2) Hatching. (3) Tadpole.

(4) At period C, the

tadpole does not feed and begins to develop into a small frog. Tail materials are absorbed and used for the development. This leads to a decrease in dry weight at this period.

2. (a) (1) At 11a.m..

(2) The guard cells have a

much curved

appearance.

(3) This causes the size of the stomata to be much increased. Gaseous exchanges, and therefore

photosynthesis are enhanced,

(b) During this period water

flows from the epidermal cells into the guard cells. From 7a,m, to lla, m, the osmotic pressure of the guard cells increases while that of the hypotonic epidermal cells remains constant. This causes the guard cells to absorb water from epidermal cells by means of osmosis. (c) The decrease in light

intensity and finally an absence of light during this period cause the photosynthesis to be slowed down and stopped. Carbon dioxide concentration in the mesophyll increases and pH of the eytoplasm of the guard cells decreases, The latter promotes the change of sugar into insoluble starch and therefore a decrease in the osmotic pressure of their eytoplasm.

(d) Since carbon dioxide in air is being absorbed by the sodium hydroxide solution, the concentration of carbon dioxide in mesophyl cannot be raised even photosynthesis is slowed down from noon to 5p, m, In such alkaline condition. the sugar in the eytoplasm of the guard cells remains. at a high level. Therefore the osmotic pressure has little change.

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