1973-02-06 — Page 27

REFERENCE LIBRARY

-6 FEC1973

真三第張七第日四初月正年丑癸摩室

AH

郭日備

日期 RITY HALL 二期星

光合作用所需,水草由於缺乏二氧化碳之 故而呈枯黄。

夏橋:

1978

中文中滿會考試題預習專欄]

生物科(十五),梁景桓・

本期温習内容

以延續上期:植物生理学(蒸散作用 养分的利用

·麻物之處理)

记)土壤与肥料土壤之性買方作物生長词集 二練習題

(下图為一種革数計,回答下列问题

(2)当你在使用這項蒸散計,進行蒸散室驗時 你能领悟到上列各项之意義嗎?〈

(3)在这项定驗進行時,你如何裝置,在装置

過程時特别注意那些事项?何故 使用这项儀器進行蒸散宣验,有何缺笑 2.植物如何獲得养分?這些养份如何利用 る植物美排泄悪官休和道植物と何廬理代

謝作用所生成的底物試分别说明之 何谓肥料?肥料三要素為何?何谓施肥? 施肥的方法有钱?各有何特性,

5試比較化學肥与自然肥在施用上各有

何利弊試列表比較之

6依下列图解,装置三份,君z為汐止 又,為垠土.Z;高粘 玻璃筒土,回答下列问题

水能在筒内上升 但在Z, Z.QZ的 三份裝置中表現如 何

棉花

軟樓 (2)根据()的结果表現说示這三種土質

的特性

表现

(3) 根据这些特性何者最適宜於耕作?

試解说之。

三上期答案,

/光合作用就是綠色植物利用葉綠素吸收光能 使其轉變成為化學能而蓋存於由二氧化碳与 水合成之葡萄糖分子的結構,所以光合作疃 在是一項吸能貯能的反應

光合作用的過程可以分為兩個階段

w光反應階拔(即水之光解反應);這階段是 葉綠素吸收光能,使水分解為氢氧、因而 特能轉移至氦原子,而成為个高能氦原子宮 一部分能量則存於侅AIP轉变為ATP分子 中但高能氦原子必需由TP.N(或NAD)作 為壹件,而与高能氢原子结及

> 暗反應階段(即碳素的還原反意)這階 段主需光的存在,仍继续進行,主要是藉 酶系的作用,使T.PNHH 的氢原子及能 一量轉移至与二氧化碳结合為葡萄糖分子

(光合作用遇程中之反意手骤图解)

光能 (光反應)

高能源子

APPé

IT PNH N ATP

結

(暗反應)

核同意二磷酸盐

+ APP

三碳醣磷酸盐+TPN

Z (1)一週後,小虫与水草生活如常,因為水草行光 合作用消耗了二氧化碳,而產生氧,供给小点 呼吸所需,而小宾呼吸的结果產生了二氧化 碳,供水草光合所需,故此两者共通共存。 (2)水草漸漸呈現枯黄、凋萎,因為水草本 或呼吸所產生之二氧化碳不足以供應本行

經數小時後小與死亡,因為水中缺氧 伎奥窒息至死..

綜合上述结果,可知植物行光合作用与 動物界行呼吸作用配合適宜則動植成 互依共通共生

3.植物葉肉细胞的水分蒸秀面成為水蒸氣飯 後:擴散散失於空氣中,這種失水的现象称 為蒸散作用,再散的途径有三

(a)透過表皮细胞的角質层而進行蒸散作用:

称為角皮蒸散作用

山透過基部皮孔而進行蒸散作用,称為皮花

蒸散作用

(5)透過氣孔而進行蒸散作用,称為氣孔蒸散

作用,其中以氧孔蒸散作用為最主要 蒸散作用的生理價值:

1排除適量水分,以维持细胞液渗透压,促進

吸收作用:

(3)為促使植物体内水液上界的主要動力。

(3)藉此作用,調節葉面的氣溫度,以光景,受高

熱血灼供

4:(1)量筒内液面下降: B.及C.裝置液面下降最快

其次為A,最慢為D.

4) 称量重量结果,B及C装置損失重量最大

次へ 最鳥が

(3)B於陽光下,C五風扇下面受到陽光及風的影 嚮故蒸散旺盛:故失水較多而在鐘罩内..

廈大為増加因血系最慢央水最少 据上述实验结果可以獲得下列之结谝 陽光照射風速以及空氣相对湿度大小

·均是以影嚮植物蒸散作用,進行

在水液表面加石蜡油的目的在於防止液 面的蒸發作用,以免影嚮安驗之结果

5山氯化钴纸 由蓝变红,而且上面的氯化 鈷纸变它較慢軽评和下面氯化 鈷纸变色較块較深,

(2) 氯化鈷纸乾燥時呈蓝色湿润時呈

红色,由於下表面氧孔交上表面故由氣 孔蒸散之水蒸氣下表面較上表面為法因 海下表面化鈷妻を軽快 2 由此實驗証明葉面有蒸散作用

下表面之蒸散作用較上表面為块 白植物除蒸散作用外,更可以藉重去喊最

之排水孔,以水液状態排出水滴林鸟诺书

作用或叫默沉作用這現象多店生於空氣濕 度太大,植物不能行蒸散作用時行之 蒸散作用与滴透作用之異同比較如下表

蒸散作用

滴透作用

!多在夜間進行

1.在日间有陽光下進行 2.在相对湿度較低時進行,在相对湿度大時進行 香水蒸氣経書表面・氣れる結音楽感東藩三柳

或表皮角質及擴散云外水孔排出

安:以水蒸氣狀態排污o)以水器(液狀进入 5. 排示的冰為純水不舍,排水及溶解有無機 無雜質食

6. 有減低葉部温度之作用6元进作用

有促進植物吸收水7.主此等敏度 ∵液上升的生理效應。

8.两者均為排出体内過量水粉调節体内水

分含量的生理作用。

7. u, A简内液面上升口同内液面下降

A筒内石灰水星白色混濁8筒内4 保持澄清状態

由於A筒内種子萌荩進行吸作用吸

C.Hi.0 + 60.

二氧化碳被石底水吸收生成白色候内等等新

Cal•H) + CO2~

CaCO1LTHO

周继之文化使A简内空机密度下降压的 減低所以水液自B简相向A简

種子萌舊時行呼吸作用吸取空氣中之 氧而釋放出氧化碳

【83英文中學會考試題預習專欄:

經濟及公共事務科(十五)

Economic & Public Affairs

(15)

A. What is the economic signif cance of the Stock Exchange?. B. *Speculation in the Stock Market has done more virture than vice" Discuss.

Answer: (A):

Stock Exchange is a market:

where sellings and buyings of securities take place. There are four Stock Exchanges in Hong Kong, They are namely; The Hong Kong

Stock Exchange, The Kowloon Stack Exchange, The Far East Stock Exchange and The Kam Ngai Stock. Exchange. Stock Exchange has definite economic significance on provid- the society. At least, it

es an investment outlet to invest -ors. However, it cannot. rule out. the possibility of speculation in the Stock Exchange. Some of the more important economia functions Pare listed below:

Firstly, investors are able to use their investment fund on a more flexible basis. They are given freed on to choose the kind of securities to invest in. Of course, they must base on finan- cial information provided by the company before they make invest- ment decisions. The correct

attitude of an investor is to examine and analyse the relevant financial information of the.

company... when they make decisions. That is why Balance Sheets and. Income statements of companies must be released in order to

protect the rights of investors against possible risks of being ais-infomed.

Secondly, investors are given expert advice and detailed inform mation of the securities they are interested in Stock Exchange

often reflecte the condidence or the public in particular securiti -es. If the possible future divid- end repayment is high, investors have more confidence on the oper ation of the company. Since divid -end repayment is an indicator showing the operating efficiency of the firm. It is essential that

·relevant information is provided Investors therefore tend to base partly on their own judgment and partly. on the expert advice from: Stock Exchange.

Thirdly, new companies can raise capital through the issue of shares. Therefore, the stock exchange is a channel through which capital can be raised. Companies can issue new shares to be bought and sold in the Stock Exchange provided they comply with the legal procedures as laid down by the Government. Without the existence of Stock Exchange, it is rather difficult to raise capital of companies

Fourthly, the stock exchange gives a current measurement of the value of different types of assets assuming no speculation has been observed in the Stock Exchange. The rising and dropping of the security prices reflect the true value of the assets of the different companies. An in- crease in the price of a particul -ar share shows that the assets of that particular company have been increased in value simply because of efficient operation and management of that company.

Lastly, Government makes use of the Stock Exchange to borrow from the public. By the issue of treasury bills and Governinent Bonds, the Government can offer them to be bought and sold in the stock market. This is important to the country since it can finan -ce the expenditure of the vari- ous Government Departments before revenue can be obtained in the subsequent financial year.

(B) The justification of specul. ation in stock market depends on the particular situation in the market economy as well as individ -ual's viewpoint. In the past. speculation was condemned on moral basis, but eince business necessarily incorporates such an element of risk-taking, a recent appraisal of speculation is made from an objective point of view. To say apeculation is more virtu

日六月二年三七九一屡公年二十六國民湖中

ous than vicious or vice versa. then will be too subjective a statement;

Like other economic phenomena,

speculation has its advantages and disadvantages.

From a broad economic stand- pounty

apeculation is a necessary" function because venture capital or assumption of risk inherent in riskier opportunties is necessary for economic growth and develop- ment, and financing of innovation and change. Capital is made avail- able to new and untried enterprise: which could not be started at all

oso be appealed 1f investors had to

to for necessary funds. Newel Industries particularly, get their start because speculators. are. willing to buy their securities before they have become seasoned.

The credit resources of the nation are mobilized for tha financing of enterprises in their promotion stages, or those that: are not strong enough financially to have an investment appeal. Through bank loans on securities, speculators are able to purchase

safe. N such speculative issues, guarding the bank against loss.

Speculation may act as a stabilizer, though an imperfect oney of security prices. The apeculator may be the only one" who cares to buy sécunties when the outlook is clouded, and con- versely, he may sell short and so e supply stocks when investors are

optimistic,

tran-

f Because of speculation, sactions and prices w will rise. This might be interpreted as a good indicator showing confidence- in the economy. More businessIA done: means more stamp duty, hence increasing revenue. Even though

this might be an illusion, better than indifference"

19

Since speculators are usually interested in the short run, they will be less likely to interfere. with management policy. More fre

quent changing hands of stocks. will mean less loss of control over management. Marketability and liquidity of the stocks will be promoted, , while the absence of speculators may lead to no buying and selling at all.

!

Despite of these, speculation is not without its demerits.

Speculation may exaggerate security price awings by causing excessive buying on the rise and thus excessive liquidation on the decline. As a result, losses due to such price swings can discour age investment of savinge in stocks by others.

An interpretation discouraging speculation may arise from the increase in transactions and prices. Such result may give false impression to the public. If in-

·vestments are made on such mis- leading impressions; scarce re- sources. To managers and execut- -ives, it may even affect the

formulation of financial policy: of company. Again, inefficiency in allocation will result.

Speculation is also vicious in the sense that it can. always aggravate the inflationary situat -ion of the economy, for a rise in stock price and retai1 price will lead to more speculation.

Speculation that involves credit in large amounts may exaggerate economic fluctuations. It can affect economic conditions when it takes the form of exten- sive purchasing of securities with bank credits, and so expands credits without reference to. business or consumer needs. Hence remedy such as regulation of security loans has to be employed.

Because of these merits and demerits, it is difficult to justify the role of speculation in stock market. Usually in boom- ing days speculation is more vicious than virtuous, while during depressive, gloomy periods. apeculation is preferred. To conclude, whether speculation is vicious or virtuous will depend "on the aituation of the economy. and the individual's point of view.

uestions for next week.

A Multiple-choice exercise will be given.