1967-02-23 — Page 14

百二第張四第

日五十月正年丁膺

育教僑華

中文中學會考試題預習專欄

are

寶效健機

round

scattered near

the mesogloea. They give off nerve-fibres. (twoo

物理科(十七)

·鄧炳恩·

聲波和聲速填-

題及問答計算題題解

歌爲两年,分有下午

有意譪修者宜速報名

學名实爆

,可其加歡大欢

会咥未袋 拜酒的

文中小學及中學之現加,

·班爲不補學會之中英滋師者,均成申請会 酒栩參加,每位 一十河元云。八浩》

-卲摩可辩娶辦之琵鷺,在私立成政府資助中 (新朏)由歎 猫學魔者,以及現行者实聯歡,底座南

在被節而像,門 澳洲皇家外科學院 在港舉行獎學金試

在職致師訓締班」,極致而未船列名被走標,至大观

樓

日英文之中

·

KIU YAT PO #

·報[中英文中小學教師, 於任教時,奧朗牌任

英語講授,但現有之 7)一,將成爲分将激师,

小學教師訓經班,用 倫快。經髙六黼种後

院

大月間在本港舉行。 醉觚初級研究疑學金孝試,將於宗

月八日、九日考試 報名定三月六日截止 六 * 斯特拉信外科學

文中學會考凖转跟有 而隆服录少爲本英

任教師及英文科彰師

可以策各尙檢定敦的 成小路托任認可之客 ,在潮巳任發三年,

十一...,凡及在職之中學

瀜期不予接變。 。參加此項考試之名於三月六日截止, 舉行,口試則於六月11日號其熱後行 张强考試之旅试將於六月八日及九日

嗨氏大盤務處衛生總監李取。 . 部名表格及考試規則之則本向希望 依現考試須有最少四人報名參加方于

日三廿月二年七六九一麽公年六十五國中:

養

樂

台播出, 。全部比賽渦程及痛类儀式錄音後,於三月二日晚七時在香濶髅 畢之後,隨助行頒獎典繞,請響社大學中文系篮六顯歌授主持 决赛定今日下午沉時四十五分花大會做營然與魯行,决碤宅-

恩施,书于舘,苦功。「港 尹崁昭,幽文彬,瀅央徠,梁贺漢;民生醫院方面恽倞榮察,泆 :留於今日出席决粪之雙方代表偬-東華三院第一中學方面協

|網球技術電影

設之後,由民生書院及東華三院第一中嵝得决嵗帶。 有本港十四京中英文中巫參加,招過初賽:馊蜜及準决荽俠們營 八時凯:香满電台主辦,三校際中國文史常将容出,共 隨請饒宗頤教授頒獎

今晚五時三刻在大會堂舉行

三院一中對民生

文史常識大決賽

【薛证者,必須持有無

贈與教育司署

網球教練示範

∴八港媒池氏於本月廿一日將

由陳象池氏捐出 澳洲 敎師三年以上之能抓

四文

辦事及富, 撦品烟黑教育 醫 參加受訓者,可啕 在已開始接受申請, 此項慈班,現

• 導肚禸社長?塹陳氏宗親會永盤榮營會

三盼裙之著名澳洲網球線比爾基路處 * 該过影片說明打網球技,由去年

敦安瓶商洽。【豬)

五年訪港之美爾號脊辣示鐵者。. 至殊價值,各校欲借用,可向教育引驎碱酸 ,上述十六米耀之電影片,對學校有時 教育可爭。此項田徑技術,保由於一九六 1前會將一珽明田徑霾斯之影片與

3氏爲西街坊潑我會會長,採啓慈

|撂蕾實世影片在教育司與狄可司簡乃

師專科學院镔取表 萬垭夫,柏立基閣

中大校外部 年九月開觑。

加幣試及口試。遴 日,地點,往 選之及格者,將於本

期蛊

日本年度師訓班

廿五春宴聯歡

應用文科同學

盘

報名經告開始有極高,該用

填-

題

英文中學會考試題預習專欄精

In the mesogiova.

“坚最低音江波長為11.33米,最高节之

(iv). NERVE CELLS: These cells

讓長為0.017米

生物科 (十七)

·山度士·

解

入V

BIOLOGY

f

S.S.Sandhu

最低鲁之波長=252=

340

30

(B.Sc.Dip.Ed)

340 20000

= 11.33巷

=0.017

1. Give the Structure of Hydra,

TENTAC

Hypostome

苏此人与第一峭壁間之距离为340米

ECTODERM

聲音來回其間之時間焱太秒,則人 峭壁開之距為11020-5)来 聲音来回其間之時間為(+2)秘

NERVE CELL

ENDODERM

ENTERON

VA

(5

340x李

ad

{l020-S=

=.340. X ·

4. 縱波

@_512x 5=340.

述

5.手速為327.68 /秒,當時氣溫

√11024x2=== 327.68.5/49

€* 327.68=133 L13 T10.6 £)

- 3.62 - -6°C.

°C

問答計算題

介質傳播

儀器真空电给(或開鐘),抽風機

图拖粉机码疆内宝船徐

徐您

抽嗎

声逐漸

躬不到若將噪 氣再度放入罩内,时 书 又前次强由此可见乍

频

̇抽蒸机

:

·

高铁声波相同,則該発音述空自

NEMATOULAST-

It is a tiny multicellular animal found in.

water ponds, poola or slowly flowing"streams . It Bedentary animal and remains attached to the stones weeds by its BASAL DISC or FOOT, with its long tentacles waving in the water for catching its prey. In the labor” atory hydra can be bred by introducing a pair into a fish tank. They may also be found in very old fish-tanks) attached to the bidea_of_th

2.STRUCTURE OF BODY WAT

body wall it. can be

Layers ECTODERM

GLOEA is not rega consist of celle plasmic and is not sides of the Ecto which have a two BLASTIC. The same

on of the of three

117 ME30- doesy hot:

mot proto!

By the inner Such animals led-DIPLO

Suth and the anus..

TEUTODERM: It is made up of several kinds of cells: (A) MUSCUIO-EPITHELTAL CELLS; These are the most.

numerous cells, They are broader at the outer enda and narrow at the inner ends towards the mesogloea. Therefore the adjacent cells form a continuous Burface on the outside forming the body-wall: They inner end forms two tail-like processes; the structure of which is muscular. These processe run up and downwards so that when they contrach the body of the hydra contracts. If the muscle~4 tails of one side only contract then they make the body of hydra bend towards that side. Thus these. are called the MUSCULO-EPITHELIAL CELLS, MUSCLE TAIL CELLS.

(( 13 ) INTERSÄTREAL CELLS. These cells are wounded in

structure and are found in groups in the space. (interstices) between the muscle-tail cells. Theird name is derived from the name of the place where they are found.

These cells can form any other kind of cell found in the body of hydra. Therefore they act as 'reserve, cells

(111)SENSORY CELLS: These are tall or columnar cella

found scattered among the musculo-epithelial cells) all over the body of hydra. At the outer end, dau found a hair-like process which is sensitive to the' touch of chemicals, especially the ones produced in their prey, as well as light and mechanical touch, Their inner ende terminate in a fibre-iike process which is in contact with the gerve cells/

more from each nerve cell) and thus form a net-, work in the mesogloss giving rise to a primitive nervous system. These nerve cells or neurons are in contact with the sensory cells and therefore the hydrá exhibits a co-ordination of the different! parts of the body in response to the kind of stimulus received. (♥) SECRETORY CELLS: These are the cells found in the

FOOT of hydra. They secrete a sticky, gum-like substance which enables hydra to attach_itself_to a support while at rest.

(vi) NEMATOBLASTS: These cells are most abundant in the]

tentacles. They are scattered among the musculo- epithelial cells and are in groups called batteries: Inside a nematoblast is found a NEMATOCYST. Each nematocyst is a pear-shaped hollow organ inside which lies coiled a thread-like structure which is' also hollow. Some of these coiled threads have barbs near the base and scone do not have any barbs.

A small hair-like process the CNIDOCIL or TRIGGER=" HAIR projects out from the surface of the nematoblast When a prey touches the trigger-hair, the coiled . thread shoots out and the ones with the barbs piéros into the body of the prey. The poisonous fluid carried along with the thread either kills or par- alyses the prey which is then carried to the mouth by the bending over of the tentacle.

The threads without the barbs are usually much coiled and these serve to entangle around the legs or body of the prey thus preventing ita escape.

Discharged nematocysts are later replaced by new] Soñes which are produced by the intersitial calls.

ESOGLOSA: As previously mentioned it ̈is not ́regarded · as a 2nd. layer because it is not made up of cells, is structurelessy is not protoplasmic and is not living. It is produced by the' inner ends of the ectodermal and j endodermal cells for their attachment. It is a very thin layer in hydra but in jellyfish all its thickness) forms the bulk of the animal. The nervous net-work is spread in this layer.

III. ENDODERM: This layer is also`made up of several kinds of

(1) NUTRITIVE CELLS: These, like the musculo-epithelial

cells of the epidermis, are also numerous and form the endodermal lining of the enteron. Their ends { towards the mesoglosa are also produced into muscleTM tail processes but these run at right angles to the! muscle-tail processes of the musculo-epithelial cells Therefore their contraction makes the body of hydra more narrow and elongated.

Their ends facing the enteron show pseudopodia which engulf the broken-up food particles and form food- vacutoles. Some bear flagella (hair-like processes) at their ends the movements of which cause currents to. be. set up in the enteron which help to move the prey inwards and throw the waste products out of the body. These cells contain ALGA called CHLORELLA. (11)SECRETORY CELLS: These cells are found in the endo-

dermis of the Hypostome, especially, as well as the enterons They secrete digestive juices which break up the food into tiny pieces which are then ingested by the nutritive cella forming food-vacuoles. The final digestion takes place inside these cella and therefore the digestion is said to be INTRA-CELLULAR, In higher_animals it is EXTHA-CELLULAH./

Question for next week)

Explain the following of Hydra :

1. Locomotion. 2. Feeding.

NOTE: Correction in lat lesson of AMOEBion 11/2/6?

ENDODERMIS : ( Endere; "Plasma-sol ECTODERMIS (Ectoearc; Plasms-gel.

鎮案題

【算題

西核附有共鳴箱面頻李相同之 XABB向置於桌上,以解链 擊

· A或B音又另 起笑鳴,以手指压觸前者使之得

1.音調之高低由發音体 响度之强弱由参看体 七品之差别

而定。

ㄨ

$

則當

喝橡根圈附於A

上最短管長為13.5吋,若嘴口更王 为0.5吋,則在空氣中之声速

DR/

.

註明相同頭旁之發音体欢起共鳴 现象

3

米,堂20克,其两螺薤 驪繫時的爱之張力,两只200牛租則 第三諧音理論上之频中西—

。

乐空戴柱及弦之振动填-

題及問答計

*

5 一金房線長50厘米,其質量為5克

若其所曼之張力為900半顿,是 該線傳穫波之速度為

問答計算題

7試說明如何利用共鳴方法或瀏

定声音在空勤中之速度

2.試述-实验方法以就明頻率

急韃線