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育教僑頁一第張四第 日六十月四年香己 WAH KID YAT PO
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HALL 六熊皂
日一卅月五年九六九一公年八十五國民類中
英中會考生物科答案
(M)
半百
(English) 1969
Biology
Suggested Answers
(a) In addition to chlorophyll, the other essential
conditions necessary for starch production in green plants are (i) carbon dioxide, (ii) water (iii) sunlight,
emperature.
Experiment to show that chlorophyllia necessary for the production of starch in plant.
Procedures A coleus plant with variegated leaves had been exposed to sunlight for 24 hours. After that a leaf waa detached. The colour distribution of the leaf was mapped out on a piece of white paper.
The leaf then was tested for starch.. I' was first dipped in boiling water for a few minutes to kill the protoplasm by destroying the enzymes in it and to make the cell more permeable to iodine solution. It was further boiled in methylated spirit to remove the chlorophyll. In order to soften the leaf it was again dipped in boiling water. Then the lear was put flat on a watch glass and iodine solution was placed on the leaf.
Result: All the green areas of the leaf became bluish-black while the coloured areas are grey Conclusions No starch formation in the non- green araas because of the absence of
phylli in these areas.
A Variegated leaf
"Coleus plant
A parasitic animal such as the tapeworm day adapted to its paculiar mode of life in having the following structural features &
(1) It has no mouth. This is no disadvantage,
since food, already digested, is absorbed through the suckers on the sides of ita head.
(2) It has no locomotory or special sense,
organa, but this again does not matter, since it does not have to move about in search of food,
(3) It has no special respiratory organa.
These would be of no servio in any case, owing to the practical absence of oxygen. in the cavity of the host's intestine. (4) It has special organs (hooks) of attachment.
These prevent its being carried along the, gut with the food.
(5) It has a flat, ribbon-like body which
enables it to have a large absorbing aurface.
(6) It has a cuticular covering so that the
whole body surface is prevented from being digested by the enzymes within the gut of, ita host.
(b) The table below is a comparison of the
structures of spirogyra and bread mould,
Spirogyrá
Bread mould
Shape of body Unbranched, filament Branched, with
like.
Bluish black
Cell wall
Number oft nucleus
Green pigmen
Green -purple
White"
White
| Food-storage
The leaf is applied to Todine Solution
To Show That Chlorophyll is Essential For
production of Starch
b) Anaerobic respiration is a process by whion, living organisms are able to produce energy from the breaking down of food or their ownL body substances in the absence of frea oxygen,
This type of respiration is practised by some lower plants such as bacteria and fungi, and perhaps by certain higher plants. The familiar example is the alcoholio fermentation of yeast cells. The process of alcoholio fermentation can be described as the following equation:
781206
glucose)
Enzyme 20,808 + 200,
+ Energy
(Ethyl alcohol)
Experiment to demonstrate that anaerobial
Despiration occurs in the germinating seeds.
Space
Germinating
Seeds
Dead Seeds
-Mercur
Absorptive structure
Cellulose céll wall is in turn coated by a mucous membrane.
Only one nucleus, in one cell.
One or two, spiral formed chloroplas enable the plant to carry out the procesa of photosynthesis."
The gyranoid found in the spiral cheoroplasts,
The whole surface qf the filament.
Reproductiva Has no special atructure
Spores-
reproductive structure, it reproduces by means of conjugation and fragmentation.
erect. and horizon- tal hyphae.
Cellulose outer cell wall,
Multi-nucleated.
Chlorophyll absent.
Glycogen and oll droplets found in the calls.
The stolon (hori- zontal hypha) [having minute branches, the rhizoids, whi mecrete enzyme to digest the organi food into goluble and diffusible substances for absorption.
The sporangiophore gives rise to sporangium which produces spores, during the / [ssexual
reproduction.
英中數學試卷二
讀者發現有錯誤
親輯先生1本人乃陳雲中會考生,在數學試卷(二)多項選擇中,發現錯誤,但考先生 我無錯誤之可鵝。現將可延的題目證出如下:
(22) F
P pens cost q dollari. Penclis cost S dollars per dosen. Find the total cost
for to pens and 'n pencila iu dollars.
mg
an
mg
50
mg ·Sa
我的答案是
•ERPCA)
(c)
P
12
P
12
12
的全不相似。
AIRES » ARTIS: UMT : MOSKU »
Ana,
應英中有考生
19694529
(a) vnres animais and three plants found in frashe
water pond are as follower
(1) Frog
(2) Fash
(3) Dragoi-flies
(4) Spirogyra
(5) Duck weedi
Water-lily
b) Adaptations of these organisms are described):
as follows?:
YTORE
(1) The colourful, smooth, slimy and moist skin
serves for protection, sensory reception and for gases exchange between the animal and its environment.
(2) The broad and wife head connected with s
stream-lined body for easy movement in/
Water:
3) The powerful and large hind-limbs with. webbed toes are adapted for swimming in water and escaping from its enemies, (4) The cloacal aperture provides a passage
the wastes and reproductive matters. ?. (5) The eggs are covered with jelly-coats for
protection and for breathing in water.
Fish: (1) Ite body is stream-lined in shape to
minimize the friction, which caused by the water when the fish is in swimming. (2) It is clothed in scales which assist the
internal skeleton in maintaining the shape of the body and protecting itself from injury. (3) A lateral line contains minute sensory
organs that enable the fish to detect low] frequency vibrations, movements, and perhage pressure changes in the water. (4) The pupils of the eyes are large to permit more light entering the eyes. This enables the fish to see darkness and to find the movement of objects farther away,
(5) A swim bladder lying in the dorsal portion of the coelon, which is filled with gases,
It functions to adjust the specific graví of the body so that the fish
various depths with a minimu stay at
effort.
(6) It possesses fins and a powerful tail. Thes organs enable it to swim rapidly and to eoape from its enemies.
(7) It possesses gills for respiring in water.
•Columella
Sporangium
Sporangios; phone
-Stolon:
-Rhizoid!
A Mycelium (plant body) of Bread Mould
Dragon-flies:
Dragon-flies pass their early stages in water in the form of nymphs. They remain motionless on the bottom or in weeds, occasionally moving in sudden jerka. They feed on tadpole, amall insects and fish etc.
Eggs of dragon-flies are deposited in the water, often embedded in plant tissues. They hatch into tiny larvae which feed on water fleas of pond.
Spirogyrai
Spirogyra, being an aquatio plant, obtains ite) oxygen in solution, and the carbon dioxide which it gives, off in breathing also dissolves. aw in in the water. Its metabolism is the same the higher plants, except that its simple structura dispenses with the need for roots, conducting tissuss, and atomata, All the substances needed for the procese are dissolved in the surrounding water and absorbed into its/ filement through its whole body'surface.
To Show That Seeds Respire Anaerobically
Two test-tubes and a glass 'trough contained mercury, and one tube, contained germinating seeds, and the other (the control) seeds which had been killed by immersion for a few minutes in boiling water.
After a few hours, 17: was round that the › level of mercury had fallen in the experimental tube with the living seeds, owing to the production of gas. This gas had been proved that it was carbon dioxide by introducing a small piece of caustic potash to the top of the tube. When the piece of caustio potash waỆ introduced into the tube, and the level of. mercury rose to top of the tube again. No change was observed in the conti.1 test tube.N Since the giving out of carbon dioxide ia an evidence of respiration, thus this axperiment› shows that living seeds can proceed respiration in the absence of free oxygen.
-Mucilaginos membrane -Cellulose Cell-wall
membrane
protoplasmic Strand.
-proto- plasmic
Nucleus
-pyrenoid Spiral Chloroplast
-A Cell of The Filament OF -Spirogyra
Duck weed *
It is a tiny plant floating. Ireely on tas? water surface of pond. Since the plant is surrounded by water, the plant has no difficult- in obtaining the soluble substances in water. Therefore the roots of duck weed become slande short and have no branches. The cuticle of the, plant is thin and permeable to water. The mechanical tissues of the plant are not well developed, owing to its floating habit. Water-lily
The plant has oval floating leaves "The upper surface of the leaf has a well developed" epidermis with stomata on it. By this, the leaf is adapted for life in air. The upper epidermie has a waxy cuticle which prevents the surface of the leaf from being wetteż, The Lower epidermis is thin and has neither stomata"nor) cuticle. Water, mineral salts and oxygen can' diffuse through the lower spidermis. The leaves have many air spaces to store up air, and to float the leaves up. It has roots o embedded in the mud of the pond for anchorage.
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