1972-04-15 — Page 22

報日僑華

買二第張六第日二初月三年子壬夏

WAH KIU YAT PO

1972英文中學會考試題預習專欄:

堅道英交赛院主編

生物科

(十四)

TS Pinnule

and Soruot

Lepores

#stalk.

Biology (24)

Alternation or Generations

in some planta the fire cycle paÚTGJ through two distruct body forms alterning

·with each other. These two different forma, sometimas called generations, are tarned gametophyte and sporophyte. The gametophyte is the haploid, generation. and is reproducing sexually by formation of gametes, while the Sporophyte is the diploid generation, and reproduces: ATEJUS ally by spore formation, (Haploid means the cells passes onlyfset(n) of chromos- omes, and diploid means having two ketas. (2n) of chromosomes.

sporangium

dispersi

Spores

germi

swear.

acchegonca

Germina

Gametophyte (Haploid gener

ation)

wridiu

(a)apores

(2n)Sporangius

antheridia

Sourface

(n)anth- erozoids

Ovun

egg

esper

ation:

(21) Aygote

Anther

Sporophyte

flagelia

(Diploid generation)

(20)

MENSIYAM BBowing alternation

of generations

For a plant showing alternation or generations one of the two forms in uga - - ally lärger in size and de mors conspicu“ ous which is called the main or domina- aat generation.

Alternation 1 generat1038 19 comes mon in the gases and the ferns, In the mosses the dominant generation is the gametophyte which in the ferns, the main -SERSZALLON is the sporophyte.

sparophy

Zygote

in mogass and ferns the gametophyte is bearing specialised ex organs called: archegonia and autherídla. Each aroha g onium produces a single large ovUS OF female gamete, and an antheridium on the other hand gives rise to a large number of small artherosoids or male gemutes" (oftan flagellated) which are capable of locomotion through liquid sedius. After fertilisation a diploid sygote is formed. Soon, the zygote ban "comes a multicellular embryo which will

develop later into the sporophyte. Thin diploid sporophyte on maturation gives rise to a number of sporangia, within which haploid spores are formed, After, dehiscence of sporangia the sporam will he`dispersed, often by wind. Uni

Embryo

Graphic Lire Uyole of &

Showing alternation of generations

Characteristics of life cycle of Pere

(1) The fern plant

Bee is the apor- ophyte generation, growing wildly along the hillside and even from crevices of rocks.. Sporangia are found in special' struc tures the ventral side of the laat. salled aori

muitable conditions the sporas Wika germinate giving rise to a new gametophy The life cycle is thus alternating between the gametophyte and sporophyte Bauch. This is the phenomenon typical for plants exhibiting alternation of generationM.-

Leat

leat

Teaver (fromdl 1

terminal bu derground stem entitious roots

in played

sporangia.

(3) Spore dispersal 18 by wind in dry

....weather. (4) Spore germinates on wet soil under

wara condition, giving rise ton small (fox-ma)) areen heart shaped game- tophyte.

(5) The gematopnyte bears soza aroneg

onia and antheridia on the ventral nurface.

(6) The antherozolus swim to the arche-

gonia of the same plant or another plant to effect fertilization. (7) The argote thus formed developa dato a young sporophyte pr. fern which is dependent on the gametoph yte" for ita food supply in the early stage.

(8) The fern Plant Decomes independent

oater when it begins to carry out photosynthesis.

As a whole the fern shows very dis- tinct alternation of generations. The" aperophyte being the main generation is conspicuous while the garmatophyte is comparatively very small. Unlike the higher plante water is still essential for fertilisation.

Compare Gasstophyte and

Sporophyts of a forn

Sporophyte

Gametophyta

(1) larger in wise [4]) smaller in size

and conspica-

and inconspicu- .com

(2) with diploid(2n) (2) with haploid (n)

Dolls

(3) repoduce asexual-9) reproduc. I

ly by spores,

(4) spores 'dispozí

sad.br. wind.

ually by union of gametes

(antherosoid

and ovum)

(4) water 18 26088-

sary to bring

the antherasi.

aid to the ovuma

六期星日五十月四年二七九一公年一十六國 民華中育教僑華

灣仔六個溫習室

(SAUPARZENIKE-141KCINESK

開放供學童使用

「洛龍習室基由提阿各妣團將会析地方設出應片。該等地方環境清靜, 一完善,經常有導師指導,其餾有參放書或「成拙,更有茶水供感,實 外硭理想流習地產。六低温瞥室共可容納三百六十人左在。各温習眾地

15

坊巾 金饿下點 西隆

十五

星期一至席期六

·八石地 這地

一

下午11時至七時

CH

星期一至星期六 空下午一時花, 星期六上午九時 上午九時至下午五時

洛克

TOSKA... 灣仔星街一號.

·紧期一至星期五

下午七時至十時

下午二時至五战 大及展期日

下午七侍半至十閥

TASIN

中文大學入學資格考試

港九試塲二十二處

1.時米、被滋中文

「大學本年度入琅阡格考人 沙書院,就过洪烈育學

報考人數達七六二五名:破以往紀錄

THIE ENE)

XP DEN TE RE÷12. XUS HENCE

1910 BUEN LERY THIS NEW

BIR: SIX YERREL

(雀】)及生物,最後

日將分上

24-REEK

49EPIKKE PESCA BY SA KAN

不可言,人數,官立中喀及英文高中學,聖所。

的一天。金文深中學,而東學,中文大學新

翎中學,张咄和出念「學,美生書院,循道中

機構總餘,出示本泄一校第十處。,

KEE <EZ-D=1+1€ • }

16-LIKE18) 「貼院,九雅斯仁出院

1972

4. BC 12 112 Flic too. A DEA¥

DE £ 215-3E BLOE CRE2 = AB TAC2

直径BC:

中文中學會考 試題預習專欄

ZA0 BC

數學科(廿四)

̇張正邦 第廿三次預習題解答

*GI ZAE = AB TAO

-200 BC

2A02+212 AB TAC

X, Y LABC ZRE BC 69 = 315 15 30

AB2+ AC2 = Ax2 +AY2 + 4xY2

X MY

AM平分BC

BX

BX=XY = YC

* AB2+AC2=Ax2+AY2

+4xy?

JEDA WBC TEGM. CUM

(作图)

2 ZARTZAC2=4AM2 +BC2 (PREZIP)

BC=Bx+xY+YC (4491-85824)

・BX = XY=YC

(2*p)

BC = XY +XY+XY (152)

BC=3XY

BC2 = 9xY2

ZAB2+2AC2 = 4AM2 +9XY* ( (1) 4£X_12)}

BM = BX+XM

CM = YC TMY

BM=MC

XM = MY (AX TË)

ZAX +ZAY2 = 4AM2+XY2 (Be)) ZAB2 + ZAC2 - ZAX2-2AY2 8×Y2 ((8)-(13) AB2+AC2 = Ax2 +AY2+4XY2 (1*9) AX2+AY? +4 XY2 = AB2 +AC2

CABC - $60.51 AO, BO, COSAUR & BC. CA, PBBY N.K, H BS BR BN x CK x AB (SR202)

ΚΑ

* BNX CKX AB

ટ્રેન

•BOA ABNA

Од

NA (兩同高角形面積之比專

ACDA

SONA

DA Shetan)

NAS

BOA ACOA (1818)

OBNA

Вод

6CNA

BNA — C 4312)

同のみ

咎

W.C

BNA OCNA "ABOA BN OCOA NO LCOB СК DBOA ZA

BOA ACOL SCOA

BN

(3), (4) M †)

• AOC_A4L (R]*?*7*1)

HE

AOC ABOA SCOB

NO KA

HB

(最乖等量)

AED

CE與圓 BAED 相切,與回CHB相切, X CAD - THE X DE CE2+ DF = CD2 CE與圓BAED相切

·DEE DFMECA FBF

CAD-AR

#BE CE + OF = CD2

CETATE BAED. (BRD)

CE-CAXCD (EN-TEELE, wek 24 1. § 50w 36 +12 2 È] ・課金部奥外部で積

DF = DHX DG (18] ( CE2+OF2=CAXCO+PAXDC (ED)

CE2 +DF" - CDC CA +AD)

CATAD

CD

CDX CL

CARRER)

2(r-AE)2 + 21 == AB2TAC2 (3)4XW)

AO-1-AE

ZAE2 +48 (T-AE) = ABTAC"

Be÷zr

7 ZAE + BBC A0=AB2 THC2

£

CAE - AB2 AC2 - 2BC⋅ AO

18369°之特别角函數

例一不用来試求 5m18"之值

OLD

194 £2 X=18 By 2x=36, 37=54°

32+2x=54°+36° = 90′′

Sm 2x=637-

<243 25 mx CoX=4038-3Cost

cox (4 cos x-25m X-3)=0 Csx=0. 8=90° BX 18 BX J 14. be MFK 2 40002 X-25mx-3=0

4(1-Sm.x)-25m X -3=0 45m2x+25mx-1=0

smx= =√5-1 1 x € 18. 62 SMX Y Z IT. &f Sus X = 15- 19]= Bu * Cs36° 2 1⁄2 (JA **) 194 $27=18° || Cs 2x = cos 36°

Co

- cs22=1-25m7.

= 1-2 (√= -1)2 = 5 +

THE TREK ON * Si 9° 2111

ZN Sm

MB X=18, B√sm=sm?"

25mm == cos === Sinx - ©

Sin = + lus = = = √1+Sin

1 sm 9 & G9 #

Sin = + 4s2 = √1 + Six-

®-@ Sun === ( √1+smx - √1-5mx)

Sus==== Smg = + ( /1+ √

= # (√ 3+ √3 -√(5)

1. Sin 72° Sun 60 = √1

Ed 25 2. Con 48 - So 12 = √3 +1

Et be

#Sm 105 213

Ed B's Cos 68° 20 Gr8 20 + 6581-40

Bel te cos. 9 211

20? Sm71 32′ Goll" 28' + Smill°28′

(fn 78°32'=1