育教儒華:頁一第張八第 日七廿月二十年巳丁磨夏
育教僑華
40 & Dor Bears
1978
| 中學會考試題預習專欄
生物(十八)·梁永華·
BIOLOGY (18)
Unit 9: Genetics
TI Conventional questions:
In human beings the lack of pigmentation, called the albinism, is the result of
a recessive gene (a) and normal pigmentation is the result of its dorminant gene (A).
The following diagram shows a family tree for a number. of people.
8
12 13 14 15 Squares represent males, and circles represent females. Black squares and circles re- present normal pigmentation. White squares and circles re- present albinism.
A horizontal line is used to link up members of the same generation,
A double line indicates a marriage.
+
The offspring of a couple are connected to them by a verti- cal line.
a. State and explain the geno- type of individuale 2,5 and 13.
b. Show clearly, using symbols
A and a, what the chances are of individual 11 having child- ren who are albinos if her wife ie 1) albino ii) individual 13.
c. Explain why it is not possi-....... ble to say why individual 9 is homozygous or heterozygous for A..
c. The parents (3 and 4) of
individual 9 are heterozygous (Aa). Their phenotype indi- cates that they carry a dor- minant gene (A), and that their son (11) is albino indicates that each of them also carries a recessive gene, Since 3 and 4 are heterozy gous, their normal child may either be homozygous (AA) or heterozygous (Aa). It is why individual 9 can not be de- termined to be homozygous or heterozygous.
2. In the table below, results
are given for three separate crossings of three straine
of potato-plants (A, B and C).
Parents F1 phenotypes-
Green- Purple-sten
A X B
Bx C
A XU
X%
48%
·0%
X:%
52%
100%
U is green-stemmed. Probable
a. State and explain the pheno- type as well as the genotype of strains A and B.
b. What are X and Y ? Explain it
clearly, using symbol. N for dorninant gene and symbol n. for recessive one.
c. Show clearly what the chances are of the offspring .of (AxC) having offspring (F2) which are green-stemmed.
Ans:
a. Strain A is purple-stemmed
and is homozygous dorminant, since atrain C is green-. stemmed, the fact that all of the offspring of (AXC) are purple indicates that purple- stem is dorainant. If A is heterozygous, some of the offspring would be green- steamed. Since none of the offspring is green-stemmed, therefore A is most proba- bly homozygous dorminant.
And:
Ta-Individual 2:
He is heterozygous (Aa) since one of his children (5) is albino. Individual 5 must have received a pair of recosaiva genes, each from one of his parents. Therefore individual 2 must one recessive gene and a dominant gene for normal pigmentation as phenotype.
Individua 28
WAH KIU YAT PO
She is homozygous (aa) since she is an albino. If she has one dorminant gene or more, she should show a normal pigmentation..
Individual 13:
She is heterozygous (Aa)since she receives a recessive gene from her mother (5) who is an albino, The fact that she has normal pigmentation shows
that she must receive a dormi- nant gene from her fathor who is also normal pigmented.
b. The genotype of individual 11
is aa since he is an albino. (1) If his wife is also an
albino,
Parent: Gamete: a
F1:
аа aa
X
aa
aa ав
all albinos
the chances of children being albino are - 4/4 = 1 or 100%.
(ii)If his wife is individual
13 whose genotype is Aa,
Aa
Parent:
Gamete:
E1:
aa x
+
Ая Aa aa ая
albinos
་
normal the chances of children being albino are
2/4 1/2 or 50%.
Strain B is heterozygous purple-stemmed since the cross with homozygous reces- sive G produces about half green-stemmed and half purple stemmed offspring.
b. x = 0 (5) Y = 100%
MM X Mn
M M
M
HM Mi
all purple-stemmed
The genotype of AxC.
MM
nn
F1:
Mn Mn
Mn
Mn
F1:
Kn
Mn
MM Mn
purple
green
The chances of F1 of (Ax) having F2 which are green- stemmed are: 1/4 or 25%.
3 X and Y are two boys. X is
genotypically short. Pre- dict the height of X and Y at manhood if they had been for a long period of time during development.
(i) seriously under-nourished (ii) well-fed (1974 #KCEE) Ans:
The nourishment will affect the development of manhood, Therefore the expected pheno- types are:
well-fed
seriously
under-nourished
X:
Y tall short
short shorter
經濟與公共事務 (十六) 孔繁盛
Economic and Public Affairs
(16)
A. Trade and Industrial Devel-
opment in Hong Kong
(a) The Government's Role
To facilitate the trade and industrial development, the Hong Kong Government provides assis- tance in respect of the following services:
1. Institutional services:
The government has helped to provide institutional nesistance for industry. through the Hong Kong Trade. Development Council, the Hong Kong Export Credit Insurance Corporation, and the Hong Kong Productivity, Centre. They are financed from public funds and provide sales promotion services, a credit insurance
scheme, and various types of training and consultancy services respectively,
The government also gives financial and other support to organizations such as the Federation of Hong Kong Industries, the Hong Kong Management Association, the Hong Kong Industrial Design Council and the Hong Kong Packaging Council. 2. Industrial Training:
報日僑業
Two universities in Hong Kong provide technological
training in engineering, architecture, and
electronic science, while the Hong Kong Polytechnic provides higher technical and vocational education. The governement also runa
gone
which provide technical training at craftsman and technician level. The government also encourages and assists companies to start apprenticeship training schemes. Industrial Land Policy; The government's sale öf land is sometimes on special terms to accommodate industries which are land and capital intensive of : high technology. An Industrial Estates Provisional Authority has been set up to develop and manage the industrial estates planned for Ta Po and Yuen Long. (b)Other Services
Banking:
technical colleges f
Banks in Hong Kong specialise in the financing of international trade, They maintain extensive credit information and commercial introduction services for their clients. and those wishing to establish business with
Hong Kong. There are 74 licensed banks in Hong Kong, and many of them have branches and
correspondents all over
the world. Thus, long
Kong can offer a comprehensive banking
service in an international
scale. Besides, the
absence of foreign exchange
control allows a speedy handling of transactions,
Insurance:
There are
many insurance companies represented in Hong Kong. All classes of insurance are readily available. Chambers of Commerce: The Hong Kong General Chamber of Commerce repre- sents all branches of commerce and industry and includes banking, shipping, insurance, commercial and professional services. Its main aims are to foster trade and industry, to protect the transaction of business and to arbitrate in commercial disputes. The chamber is i member of the International Chamber of Commerce and the Federat- ion of Commonwealth Chambers of Commerce.
There are other organi- zations such as The Feder- ation of Hong Kong Indus- tries and The Chinese Manufacturers Association of Hong Kong, which help to promote trade and productivity.
B. Trade Restrictions
To encourage development of domestic industry and to protect existing industry, a government may establish tariffs, quotas, boycotts, exchange and psychological barriers against imported goods, The inspiration for such barriers may be economic and political, but they are typically encouraged by local industry.
1. Tariffa A tariff is.
A tax imposed by a govern- ment on good's entering its borders. Import tariffs imposed by the foreign country are probably the major impediment to trade with another country. All countries have tariffs for the purpose of raising revenue or protecting home industries from the competition of foreign- produced gooda, Tariff rates are based on value or quantity, or a combination of both.
2. Quotas: Countries may
also impose limitations on the quantity of certain goods imported during a specific period.
These
quotas may be applied to imports from specific countries or from all foreign countries in general. Quotas are set for a variety of reasons, the most important one being to protect domestic industry and to conserve
六期星
foreign exchange.
日四月二年八七九一篇公年七十六國民華中
3. Boycotts: A government boycott is an absolute
restriction against the.
purchase and importation
of certain goods from. other countries,
This can
be either formal or informal. and can be government sponsored or sponsored by
a given industry. 4. Exchange barriers:
In order to conserve acarce foreign exchange and improve balance of payment difficulties, many countries impose restrictions on the amount of their currency. they will exchange, for the currency of another. country.. In effect, they ration the amount of currency available to pay for imports: Exchange controls can be applied to all commodities, or a country may employ a system of multiple exchange rates based on the type of import. 5. Other restrictions:
Many other kinds of restri ctions are also imposed on imports, such as regulations affecting the importation of harmful products, drugs and medicine, and literature. Products must also comply with all government standards set for health, sanitation, packaging, and labeling. Failure to comply with the se
regulations can result in severe fines and penalties.
附加數學(十八)岑俊彦
Add Maths. 18
Solutions to Exercise
√2
1. (a)Let y=x a2 -x2
2. (b)y
-(2-2) x-(-x2)(x)
2
~ (a = x2) (1)
(-2x)
2
−(x2-4)”, n(x2+3)"=1, 2x
(x+3)2n
2nx (x2+3) " ( x2-4)" -
(x2+3)2n
-
2nx(x2+3)" (x2-4)^{(x2-4)−1
(x2 +3) 2
−2nx (x2 «4) ^ ( x2 + 3 ) " ( x2 +3)=1
(x2+3)2n
2nx (x2+3)(x2
2
2
2n
2nx (x2+3)" (x2-4) - 2_) (2.3)
140x(x2-4)*
2n
(x2-4) (x2+3) (x2+3)"
14nx
(x2-4)(x2+3) (x2+3)"
14nxy
(x2-4)(x2+3).
44
Ans.
3. x+y=48(xy ̈+x^y)=0
Differentiate with respect to x:
+44
4x
-48x20
3
hy
ay 8axy
dx
dx
(by3-Baxy-ax)
dy 4(ay2+2axy=x¬
4(y-2axy-ax
_(ax+2axy-x3)
ax +2axy-
4. (a)Let y 2x-3
Ans
dy_(x2+1)(4) −('x−3) (2x)
+1) 2
dx
For stationary values put
2
2x-3x-2-0 (2x+1)(x-2)=0
x=- or 2
ye-4 or 1
*
R L 2.
R
0 漏 + 0
dx
Ans
at
dy (1+x2) 2. ¿(1-x2)-, (-2x). (1+x2)
-(1-x) (1x2)-(2x)]
· (1+x2).
(1«x2)2 = (1+x2)"
1+x
--=(1+x2) - x ( 1 − x2)
(1-x2)-(14x2)*(1+x2) .
-2x
· (1−x2)*(1+x2). (c)y=x2sin(3x+11)
(d)y-
-2xsin(3x+T)
+x2cos(3x+1)(3) =2xsin(3x+T)
+3x2cos(3x+11)
2
Binx+C0sx
sinx-cosx
Ans.
dy (sinx-cosx)(cosx=sinx)
dx
{Binx-cosx)
sinz+cosx) (cosx+sinx)
(sinx-cosx)
2
-9in2x+2sinxcosx-cox-x
(sinx-cosx)
2
-sin x-2sinxcosx-cos x
2
(sinx-cosx
2(ain2x
600+x
(sinx-coox)
-2
{sinx-cosx)
2
2.
dy
2
2
+3)
n
(x2+3)", n(x2-4)"
2 2n (x+3)
Ana.
2x
y bas a minimum value of 4 and at (2, 1), y has a maximum value of 1.
4x-3
(b) y 2
Ans.
When this curve crosses
the y-axis, x=0;
and y-4(0)-3-3
(0)2+1
the curve passes. through the point (0,-3) Gradient at this point is given by
dy_ −4 ( 0 ) = −6 ( 0 ) ~4
+4
.the equation of the
tangent to the curve at the point (0, -3). is given by y-(−3)=4(x-0).
y-4x+3=0
2
2
Ang.
To find the gradient, differentiate with respect to x:
dy
2x+6yX-0
Зу
3(73)
At (a,1),
the equation of the
tangent at (a,) is given by
3-(x-3)
y√3-a--(x-a)
i.e. y√5+x-2a=0
Ans.
The equation of the normal is given by
Y-3(x-a) since the
gradient of. the normal is
33
.*. y√3-a=3(x-a) i.e. y/3-3x+20=0
Ans.
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